Brown rice fermented product and use thereof

Abstract

The present invention relates to a brown rice fermented product and use thereof, and in particular, to use of a brown rice fermented product in facilitating bowel relaxing and intestinal flora regulation. It has been discovered that the brown rice fermented product can relieve constipation, has an NO scavenging effect, and can down-regulate the relative expression levels of nos1, nos2a, and nos2b genes; intervention with the brown rice fermented product can restore the species richness of intestinal flora in constipated zebrafish, and has a certain influence on the species evenness and diversity, thereby increasing the abundance of beneficial bacteria (Bacteroidetes) while reducing the abundance of harmful bacteria (Firmicutes, Aeromonas, and Enterobacteriales). The brown rice fermented product of the present invention can be widely used as a functional raw material in the field of food products.

Description

Brown rice fermentation product and its use Technical Field The invention belongs to the technical field of functional substance research, and specifically relates to brown rice fermentation products and uses thereof, and more specifically relates to the use of the brown rice fermentation products in improving constipation and intestinal flora. Background Art Rice is the third largest agricultural product in the world (reference 1), and brown rice is whole-grain rice that only retains the outer layer of tissue after the rice is roughly husked, and is composed of rice bran layer, germ and endosperm. In addition to starch, protein, fat, minerals, vitamins and other nutrients, brown rice also contains dietary fiber, oryzanol, glutathione, γ-aminobutyric acid, rice bran polysaccharides and other substances, among which the crude fiber content is 1.48% (references 2, 3, 4). Dietary fiber is a non-starch polysaccharide that can effectively prevent gastrointestinal diseases, promote intestinal peristalsis, improve constipation, improve intestinal flora diversity, and has physiological functions such as lowering blood sugar and blood lipids (reference 5). However, since brown rice is surrounded by a hard seed coat, many nutrients are in a bound state and are not easily absorbed. In particular, brown rice contains more cellulose, so it is not easy to cook during processing and cooking, and has certain limitations in taste experience. Current research has found that by using a fermentation process to treat brown rice, not only can the flavor be improved, but also new nutritional value can be given to brown rice (reference document 6). Reference document 13 discloses a brown rice fermentation product rich in multiple active ingredients and its preparation method, which improves the taste of brown rice, enriches and increases the content of soluble dietary fiber, is rich in probiotic metabolites, VB 1 ,VB 2 , VE, amylase, protease, and lipase contents are all increased, and can be applied to various products. Reference 14 discloses a method for preparing a brown rice fermentation stock solution for cosmetics and its product, which provides a method for preparing a brown rice fermentation stock solution with a short production cycle, stable products, high content of active substances, and whitening effect that can be used in cosmetics. Reference 15 discloses a method for preparing a rice fermented beverage, which adopts the steps of mixed fermentation of lactic acid bacteria, double enzyme treatment, and ultra-high pressure treatment to improve the unique taste and aroma of the product. Reference 16 discloses a rice fermentation extract and its preparation method and application, which confirms that the rice fermentation product prepared in this way has the effects of high efficiency anti-inflammatory, allergy and skin repair. On the other hand, in recent years, zebrafish has been frequently used as a new and cost-effective animal model to evaluate the efficacy of food and drugs and their impact on human health and safety (citation 7). Zebrafish has a gastrointestinal tract structure similar to that of humans, which consists of endothelial cells, connective tissue, outer longitudinal muscle, and circular muscle. Moreover, the body of juvenile zebrafish is transparent, making it easy to observe the motility characteristics of the entire gastrointestinal tract (citation 8). Aluminum sulfate can be used to induce a constipation model in zebrafish. Aluminum sulfate can absorb water in the intestine to form crystal water, causing dry stools. At the same time, it inhibits intestinal peristalsis and propulsion, ultimately leading to constipation (citation 17). In addition, neurotransmitters in the colon control its motility. Nitric oxide (NO), as a major neurotransmitter affecting intestinal motility, plays an important role in the functional activities of the gastrointestinal tract (citation 9). Currently, some studies have shown that NO may inhibit intestinal motility and trigger the occurrence of constipation by relaxing smooth muscle in a way that reduces intracellular Ca 2+ concentration or reduces the factors causing contraction on the Ca 2+ sensitivity (citations 10, 11). Citation 12 discloses a composition and method for treating constipation and other gastrointestinal system diseases, using the intestinal NO concentration as an indicator for drugs to improve constipation and other gastrointestinal system diseases. Nitric oxide synthase (NOS) is the key enzyme for endogenous NO production. Currently, three types of NOS are known, including endothelial tissue (eNOS or NOS3), nervous system (nNOS or NOS1), and cytokine-induced type (iNOS or NOS2) (citation 18). Some studies have shown that intestinal motility can be promoted by increasing the mRNA expression of glial cell derived neurotrophic factor (GDNF) and decreasing the mRNA expression of NOS (citation 19). Other studies have shown that the imbalance of the intestinal flora affects the occurrence of constipation. The intestinal flora of constipation patients is disordered, often manifested as a decrease in the abundance of the flora, a significant reduction in the abundance of beneficial bacteria, and a significant increase in the abundance of pathogenic bacteria (citation 20). The imbalance of the intestinal flora leads to abnormalities in itself and its metabolites, and then leads to abnormal intestinal motility (citation 21). Currently, there is no publicly available information that can confirm the efficacy of brown rice fermented products in improving gastrointestinal conditions and the mechanism behind it, nor are there any reports on the improvement and regulation of the intestinal flora by brown rice fermented products. Citation: Citation 1: Punia S, Sandhu KS, Grasso S, Singh Purewal S, Kaur M, Kumar Siroha A, Kumar K, Kumar V, Kumar M. Aspergillus oryzae Fermented Rice Bran: A Byproduct with Enhanced Bioactive Compounds and Antioxidant Potential. Foods. 2020 Dec 31;10(1):70. Citation 2: Yang Y, Guo M, Sun S, et al. Natural variation of OsGluA2 is involved in grain protein content regulation in rice[J]. Nature Communications, 2019, 10(1). Citation 3: OECD, Revised consensus document on compositional considerations for new varieties of rice (oryza sativa): key food and feed nutrients, anti - nutrients and other constituents, 2016, Organisation for Economic Co - operation and Development, Paris Citation 4: Lv Chengwei, Yue Yulan, Wang Zheng, Li Zhuolin, Li Tiezhu, Hu Jimei. Research progress on the nutritional value and processing technology of brown rice[J]. Science and Technology of Cereals, Oils and Foods, 2020, 28(6):5. Citation 5: Huang Suya, Qian Bingjun, Deng Yun. Research progress on the functions of dietary fiber[J]. The Food Industry, 2016(1):5. Citation 6: Gallo M, Nigro F, Passannanti F, et al. Rice Fermentation by Lactobacillus Paracasei CBA L74[J]. 2018. Citation 7: Mcgrath P. Zebrafish: Methods for Assessing Drug Safety and Toxicity[M]. John Wiley & Sons, 2011. Citation 8: Rich A. A new high-content model system for studies of gastrointestinal transit: the zebrafish[J]. Neurogastroenterol Motil, 2009(3). Citation 9: Idrizaj E, Traini C, Vannucchi M, et al. Nitric Oxide: From Gastric Motility to Gastric Dysmotility.[J]. International journal of molecular sciences, 2021, 22(18). Citation 10: Fan Yufeng, Jiang Ming, Huang Xueqin, et al. Nitric Oxide and Slow Transit Constipation[J]. Chinese Journal of Anorectal Diseases, 2016(2): 3. Citation 11: Dang Yue, Tian Mengyuan, Wang Chengxiao, et al. Study on the Laxative Effect and Mechanism of Moringa Oleifera Leaf Extract on Constipated Mice[J]. Chinese Traditional and Herbal Drugs, 2021, 52(14): 7. Citation 12: Thomas Julius Polodi. Laxative Compositions and Methods for Treating Constipation and Related Gastrointestinal Diseases and Conditions: CN201380056438.5[P][2023-08-28]. Citation 13: CN202111559673.7; Citation 14: CN201810171483.X; Citation 15: CN201410261208.9; Citation 16: CN202010254708.5; Citation 17: Talley N J, Jones M, Nuyts G, et al. Risk factors for chronic constipation based on a general practice sample[J]. American Journal of Gastroenterology, 2003, 98(5): 1107-1111. Citation 18: Knyushko T V, Sharov V S, Williams T D, et al. 3-Nitrotyrosine Modification of SERCA2a in the Aging Heart: A Distinct Signature of the Cellular Redox Environment[J]. Biochemistry, 2005, 44(39): 13071-81. Citation 19: Fan Yihong, Xu Guoping, Feng Wen, et al. Effects of Zhizhu Tongbian Decoction on Colonic Ink Propulsion Rate, GDNF and NOS mRNA Expression in Rats with Slow Transit Constipation[J]. Chinese Journal of Integrated Traditional and Western Medicine, 2012, 32(4): 4. Citation 20: Shi Min, Liu Fulin, Xia Xuting, Liao Chenmin. Research Progress on Traditional Chinese Medicine Regulating Intestinal Flora in the Treatment of Slow Transit Constipation[J]. China Medical Herald, 2022, 19(32): 47-50. Citation 21: Choi C H, Chang S K. Alteration of Gut Microbiota and Efficacy of Probiotics in Functional Constipation[J]. Journal of Neurogastroenterology & Motility, 2015, 21(1): 4-7. SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION At present, there are numerous studies on brown rice fermented products, but they still mainly focus on their preparation methods. A small amount of prior art has explored the efficacy of brown rice fermented products in improving skin conditions and applied them to the cosmetics field. There is still room for development in the research on brown rice fermented products. Based on the above research on the efficacy of brown rice fermented products in the prior art, when studying the possible biological efficacy of brown rice fermented products, the present invention newly discovers that brown rice fermented products have an obvious improvement effect on constipation, and unexpectedly discovers that brown rice fermented products have an obvious regulatory effect on constipation-causing or intestinal flora disorders caused by constipation. SOLUTION TO THE PROBLEM The present invention discovers that the above technical problems can be solved by the following technical solutions: [1]. Use of brown rice fermented product in the preparation of a food or health food that helps moisten the intestines and relieve constipation and / or helps regulate intestinal flora, wherein the preparation method of the brown rice fermented product comprises the following steps: Inoculation step: Place brown rice in a fermentation container and add a fermentation bacterium accounting for 0.1 - 1% of the mass of the dry brown rice. Fermentation step: Seal the fermentation container and carry out fermentation, where the fermentation temperature is 22 - 37°C and the fermentation time is 30 - 45 hours. [2]. The use according to [1], characterized in that the brown rice is processed through the following steps: Cooking step: Steam the rice until the grains expand, are hard on the outside and soft on the inside, and have no uncooked core. [3]. The use according to [1] or [2], characterized in that the fermentation container has a volume of 10 - 50 L for every 1 kg of dry brown rice, and the thickness of the brown rice in the container does not exceed 20 cm. [4]. The use according to any one of [1] - [3], characterized in that the fermentation bacterium includes Rhizopus. [5]. The use according to any one of [1] - [4], characterized in that the facilitation of laxation and / or regulation of the intestinal flora includes any one or more of the following: improvement of constipation, clearance of intestinal NO, down - regulation of the expression of the NOS gene, increase in the abundance of beneficial intestinal bacteria, and decrease in the abundance of harmful intestinal bacteria. [6]. The use according to [5], characterized in that the NOS gene includes any one or more of the nos1 gene, nos2a gene, and nos2b gene. [7]. The use according to [5] or [6], characterized in that the beneficial intestinal bacteria include probiotics of the phylum Bacteroidetes. [8]. The use according to any one of [5] - [7], characterized in that the harmful intestinal bacteria include any one or more of the bacteria of the phylum Firmicutes, Aeromonas bacteria, and Enterobacteriales bacteria. [9]. The use of an edible product for facilitating laxation and / or regulating the intestinal flora, characterized in that the edible product contains the brown rice ferment obtained according to any one of [1] - [8] or is prepared from the brown rice ferment obtained according to any one of [1] - [8].

[0010] . The use according to [9], characterized in that, based on the total mass of the edible product, the content of the brown rice ferment is 1 - 90% by mass. Effects of the invention Based on the implementation of the above - mentioned technical solution, the present invention can achieve the following technical effects: The experimental data of the present invention show that the fermented brown rice product provided by the present invention has good effects in preventing intestinal constipation (i.e., helping to moisten the intestines and relieve constipation) and improving the structure and abundance of the intestinal flora (i.e., helping to regulate the intestinal flora). Its specific manifestations are, for example: improving constipation and NO scavenging effects and being able to down-regulate the relative expression levels of nos1, nos2a, and nos2b genes; after the intervention of the fermented brown rice product, the intestinal flora disorder can be improved, the species richness of the intestinal flora of constipated zebrafish can be called back, and it has a certain impact on species evenness and diversity; after the intervention of the fermented brown rice product, the intestinal flora structure of constipated zebrafish changes, the abundance of beneficial bacteria (Bacteroidetes) can be increased, and the abundance of harmful bacteria (Firmicutes, Aeromonas, Enterobacterales) can be reduced. Generally, the fermented brown rice product (such as freeze-dried powder of fermented brown rice) may achieve the function of preventing constipation by reducing the NOS gene expression level, and can improve the intestinal flora disorder caused by constipation. As a functional raw material, the fermented brown rice product of the present invention has a wider range of applications. The carriers can be foods, health foods, drugs, cosmetics, etc., and the dosage forms can include powders, tablets, granules, oral liquids, capsules, jelly candies, beverages, dairy products, soy milk, etc. Intaken in the form of oral administration, it can fill the gap of products with the effect of preventing constipation. Brief Description of the Drawings Figure 1: Typical diagram of the intestinal fluorescence intensity of zebrafish after treatment with freeze-dried powder of fermented brown rice; among them, the dotted box is the analysis site of the zebrafish intestine. Figure 2: Analysis diagram of the intestinal fluorescence intensity of zebrafish after treatment with freeze-dried powder of fermented brown rice; among them, compared with the model control group, *** indicates p < 0.001. Figure 3: Typical diagram of the intestinal NO fluorescence intensity of zebrafish after treatment with freeze-dried powder of fermented brown rice; among them, the dotted box is the analysis site of the zebrafish intestine. Figure 4: Analysis diagram of the intestinal NO fluorescence intensity of zebrafish after treatment with freeze-dried powder of fermented brown rice; among them, compared with the model control group, ***p < 0.001. Figure 5: Analysis diagram of the relative expression level of nos1 gene. Figure 6: Analysis diagram of the relative expression level of nos2a gene. Figure 7: Analysis diagram of the relative expression level of nos2b gene. Figure 8A: Analysis diagram of the species diversity of intestinal flora; among them, the vertical coordinate is the Shannon index; in the box plot, the upper and lower end lines of the box: the upper and lower quartiles (Interquartile range, IQR); the median line: the median; the upper and lower edges: the maximum and minimum inner values (1.5 times of the IQR); the points outside the upper and lower edges: represent outliers. The numbers on the connecting lines between the columns are the P values of the T test (if the P value > 0.05, the P value is default not to be displayed). Figure 8B: Analysis diagram of the species diversity of the intestinal flora; among them, the vertical axis is the Simpson index; in the box plot, the upper and lower lines of the box: the upper and lower quartiles (Interquartile range, IQR); the median line: the median; the upper and lower edges: the maximum and minimum inner values (1.5 times the IQR); the points outside the upper and lower edges: represent outliers. The numbers on the connecting lines between the columns are the P values of the T test (if the P value > 0.05, the P value is not displayed by default). Figure 9: PCA analysis diagram; among them, the horizontal axis represents the first principal component, and the percentage represents the contribution value of the first principal component to the sample difference; the vertical axis represents the second principal component, and the percentage represents the contribution value of the second principal component to the sample difference. Figure 10: PCoA analysis diagram; among them, the horizontal axis represents the first principal component, and the percentage represents the contribution value of the first principal component to the sample difference; the vertical axis represents the second principal component, and the percentage represents the contribution value of the second principal component to the sample difference. Figure 11: NMDS analysis diagram; among them, the horizontal axis represents the first principal component, and the percentage represents the contribution value of the first principal component to the sample difference; the vertical axis represents the second principal component, and the percentage represents the contribution value of the second principal component to the sample difference. Each point in the figure represents a sample; different colors represent different groups. When Stress is less than 0.2, it indicates that the NMDS analysis has a certain reliability, and the closer the samples are on the coordinate graph, the higher the similarity. Figure 12: Diagram of the compositional changes of the intestinal microorganisms of each sample at the phylum level; among them, the horizontal axis is the sample name (1, 2, and 3 represent 3 biological replicates respectively); the vertical axis is the relative abundance percentage. Different colors represent different species; the stacked columns are the top 10 taxa in relative abundance at each taxonomic level. Figure 13: Diagram of the compositional changes of the intestinal microorganisms of each sample at the order level; among them, the horizontal axis is the sample name (1, 2, and 3 represent 3 biological replicates respectively); the vertical axis is the relative abundance percentage. Different colors represent different species; the stacked columns are the top 10 taxa in relative abundance at each taxonomic level. Figure 14: Diagram of the compositional changes of the intestinal microorganisms of each sample at the genus level; among them, the horizontal axis is the sample name (1, 2, and 3 represent 3 biological replicates respectively); the vertical axis is the relative abundance percentage. Different colors represent different species; the stacked columns are the top 10 taxa in relative abundance at each taxonomic level. Figure 15: Evolutionary cladogram of differential species from phylum to genus (LEfSe analysis); among them, the circles radiating from the inside to the outside of the evolutionary cladogram represent the taxonomic levels from phylum to species; each small circle at different taxonomic levels represents a taxon at that level, and the diameter of the small circle is proportional to the relative abundance. Different colors represent different groups, and the nodes of different colors represent the microbial communities that play important roles in the groups represented by the colors. Figure 16: Bar chart of LDA value distribution (LEfSe analysis); wherein, the abscissa represents the LDA value obtained from LEfSe analysis, and the ordinate represents the microbiota that plays an important role. Figure 17A: Analysis diagram of the characteristic microbiota (Methylobacterium and Beijerinckiaceae) of the blank control group selected in Figure 16; wherein, the ordinate is the LDA value of relative abundance. Figure 17B: Analysis diagram of the characteristic microbiota (Bacteroidetes and Rhizobiales) of the sample group selected in Figure 16; wherein, the ordinate is the LDA value of relative abundance. Figure 17C: Analysis diagram of the characteristic microbiota (Gammaproteobacteria, Enterobacterales and Aeromonas) of the model control group selected in Figure 16; wherein, the ordinate is the LDA value of relative abundance. Detailed implementation manners The following describes the implementation manners of the present invention, but the present invention is not limited thereto. The present invention is not limited to the various components described below. Various changes can be made within the scope claimed in the invention, and the implementation manners and embodiments obtained by appropriately combining the technical means respectively disclosed in different implementation manners and embodiments are also included in the technical scope of the present invention. In this specification, the numerical range expressed by "numerical value A to numerical value B" refers to the range including the endpoint numerical values A and B. In this specification, the numerical range expressed by "above" or "below" refers to the numerical range including this number. In this specification, the meaning expressed by "can" includes the meanings of both performing a certain process and not performing a certain process. In this specification, the use of "optional" or "optional" means that certain substances, components, execution steps, applied conditions and other factors are used or not used. In this specification, unless otherwise specified, the "normal temperature" usually refers to the temperature at 23 ± 2°C. In this specification, the unit names used are all international standard unit names, and unless otherwise stated, the "%" used represents the weight or mass percentage content. In this specification, the "some specific / preferred implementation manners", "some other specific / preferred implementation manners", "implementation manners", etc. mentioned refer to the specific elements (for example, features, structures, properties and / or characteristics) related to the implementation manner, which are included in at least one of the implementation manners described herein, and may or may not exist in other implementation manners. In addition, it should be understood that the elements can be combined in various implementation manners in any suitable way. Unless otherwise defined, other technical and scientific terms used in the present invention have the same meanings as commonly understood by those of ordinary skill in the technical field to which the present invention pertains. Through biological research, the present invention has discovered new effects of the fermented brown rice product, and based on this research, has expanded the existing application methods of the fermented brown rice product. The present invention is mainly based on the following insights: Using zebrafish as the research object, the present invention feeds them with water containing a certain concentration of the fermented brown rice product. By analyzing the Nile red fluorescence intensity in the zebrafish intestine, the NO fluorescence intensity in the intestine, the relative expression level of the NOS gene, the 16S rRNA of the intestinal flora, and the species composition at different taxonomic levels, it is found that the fermented brown rice product (freeze-dried powder) has the effects of preventing and improving constipation and regulating the structure and abundance of the intestinal flora at the same time. (Fermented brown rice product) In the present invention, the fermented brown rice product refers to the product obtained by fermenting brown rice, and there is no particular limitation on the specific type of brown rice. For example, the brown rice that can be used includes one or more of japonica rice, indica rice, and glutinous rice. In some specific embodiments, the present invention preferably uses japonica brown rice. In some embodiments, the preparation method of the fermented brown rice product includes the following steps: Inoculation step: Place the brown rice in a fermentation container and add a fermentation bacterium accounting for 0.1-1% of the dry brown rice mass. Fermentation step: Seal the fermentation container and carry out fermentation, wherein the fermentation temperature is 22-37°C and the fermentation time is 30-45 hours. In some embodiments, the brown rice is processed through the following steps: Cooking step: Steam the rice until the grains expand, are hard on the outside and soft on the inside, and have no uncooked core. I. Inoculation step: In some specific embodiments, the step of inoculating bacteria is the step of placing (cooked) brown rice in a fermentation container and adding fermentation bacteria. Any fermentation container in the food industry can be used as the fermentation container. From the viewpoints of optimizing the alcohol content, smell, texture and taste of the fermentation product, and being more conducive to laxation and regulating the intestinal flora, the fermentation container preferably has a volume of 10 - 50 L (i.e., the volume ratio of dry brown rice to air in the container is 1:19 - 1:49), preferably 15 - 45 L, per 1 kg of dry brown rice, and the thickness of the brown rice in the container does not exceed 20 cm, preferably does not exceed 18 cm. Without being bound by theory, it is considered that if the volume is less than 10 L, more alcohol will be produced, and if the volume is more than 50 L, the supply amount of oxygen is too high, which is not conducive to the progress of fermentation. In addition, if the thickness of the brown rice in the container is too thick, the air permeability will decrease and more alcohol will also be produced. On the other hand, the lower limit of the thickness of the brown rice is not particularly limited, but if it is too thin, the production cost will increase, so it is not preferred. Therefore, in the present invention, it is preferably 2 cm or more. In a specific embodiment, the fermentation container used has a volume of 30 L (i.e., the volume ratio of dry brown rice to air in the container is 1:29) per 1 kg of dry brown rice, and the thickness of the brown rice in the container is 15 cm. The present invention has no particular limitation on the fermentation bacteria that can be used, and fermentation bacteria commonly used in food work for fermentation can be used, such as Rhizopus and Aspergillus can be cited. From the viewpoint of reducing the alcohol content, Rhizopus is preferably used. Without being bound by theory, Rhizopus can produce a small amount of zymase and has a certain alcohol-producing ability, so it can carry out the process of saccharification and fermentation simultaneously, but the alcohol-producing ability is not high, making the sweet fermented grains have a unique wine aroma in addition to the rice aroma. The addition amount of the fermentation bacteria is preferably 0.1 - 1% of the mass of dry brown rice, for example, it can be 0.1% of the mass of dry brown rice, 0.3% of the mass of dry brown rice, 0.5% of the mass of dry brown rice, 0.8% of the mass of dry brown rice, or 1.0% of the mass of dry brown rice. If it is less than 0.1% of the mass of dry brown rice, it is not conducive to the progress of fermentation, and if it is more than 1.0% of the mass of dry brown rice, the alcohol content increases and the content of soluble solids decreases. In a specific embodiment, 0.5% of the mass of dry brown rice of Rhizopus is added. In another specific embodiment, 1.0% of the mass of dry brown rice of Rhizopus is added. II. Fermentation step: In some specific embodiments, the fermentation step is a step of fermenting after sealing the fermenter treated with inoculation (for example, covering with a film, etc.). From the viewpoints that the fermented product has a high soluble solid content, a low alcohol content, excellent odor, texture and taste, and is more conducive to laxation and regulating the intestinal flora, the fermentation temperature can be set at 22-37 °C, preferably 25-35 °C, and the fermentation time can be set at 30-45 hours, preferably 32-43 hours. In a specific embodiment, the fermentation temperature can be 28 °C and the fermentation time can be 36 hours. In another specific embodiment, the fermentation temperature can be 26 °C and the fermentation time can be 34 hours. III. Cooking step: The cooking step is, to a certain extent, to increase the soluble solids in the fermented product so as to have a better effect of facilitating laxation and regulating the intestinal flora. In some specific embodiments, the cooking step is a step of steaming brown rice. As long as the brown rice as the raw material can be steamed until the rice grains expand, are hard on the outside and soft on the inside, and have no uncooked core, the cooking method is not particularly limited. For example, the cooking can be carried out by steaming the brown rice with water. The amount of water used in the steaming is usually set at 0.5-2 times the mass of dry brown rice. If the amount of water used is less than 0.5 times the mass of dry brown rice, the brown rice cannot be fully steamed. If the amount of water used is more than 2 times the mass of dry brown rice, not only water resources are wasted but also the rice grains are likely to become soft and lose their toughness, making it difficult to maintain the whole grains. The steaming temperature is usually set at 90-130 °C, preferably 95-120 °C. For example, it can be 95 °C, 100 °C, 105 °C, 110 °C, 115 °C, 120 °C. If the temperature is too low, the brown rice is not easily steamed, resulting in a longer steaming time and wasting energy. If the temperature is too high, the actual production cost will increase, so it is not preferred. As long as the rice grains can be steamed until they expand, are hard on the outside and soft on the inside, and have no uncooked core, the steaming time is not particularly limited and can usually be set at 5-70 min, preferably 10-60 min. In a specific embodiment, the amount of water used in the steaming can be 1.5 times the mass of dry brown rice, the steaming temperature can be 110 °C, and the steaming time can be 20 min. Furthermore, from the viewpoints of making the rice grains easy to steam and obtaining a fermented product with excellent odor, texture and taste, the brown rice used in the above cooking step is preferably brown rice treated through a pretreatment step. In some specific embodiments, the pretreatment is a step of making the brown rice to be fermented absorb water and soften. As long as the brown rice to be fermented can absorb water and soften, the method of pretreatment is not particularly limited. For example, the pretreatment can be carried out by soaking the rice in water at 15-25°C, wherein the amount of water used in the soaking is 1-5 times the mass of dry brown rice, preferably 1-4 times the mass of dry brown rice; the soaking time is 1-12 hours, preferably 2-10 hours. In a specific embodiment, the amount of water used in the soaking can be 2 times the mass of dry brown rice, and the soaking time can be 6 hours. In addition, from the viewpoints of improving product quality and enhancing the edible taste, the pretreatment may further include steps of removing impurities and washing the brown rice. Removing impurities refers to the step of removing impurities such as straws, rice bran, and stones that affect the product quality or edible taste and are mixed in the brown rice, and washing refers to the step of washing with water, which can be carried out by the methods of removing impurities and washing commonly used in food processing. IV. Sterilization: Furthermore, the brown rice treated by the above fermentation step is preferably sterilized by the following sterilization step. In some specific embodiments, sterilization is a step of sterilizing the fermented brown rice. Methods known in the food field can be used for sterilization. As known sterilization methods, for example, there can be mentioned the method of steam sterilization by filling the fermented brown rice into a heat-resistant package and steaming at 95-100°C for 10-30 min. In a specific embodiment, the fermented brown rice can be filled into a heat-resistant package and placed at 100°C for steaming for 20 min. The heat-resistant package used in the present invention is not particularly limited as long as it can package the fermented brown rice and can withstand high-temperature heating without introducing impurities or peculiar smells into the fermented brown rice, and heat-resistant packages commonly used in the food industry can be used. The method for preparing the brown rice ferment of the present invention may further include other steps as needed within the range not affecting the effects of the present invention. In the brown rice ferment prepared by the above preparation method according to the present invention, the content of soluble solids is preferably 30 Brix or more, more preferably 35 Brix or more; the alcohol content is preferably less than 0.5%. The present invention has no particular limitation on the form of the brown rice ferment, for example, it is a liquid (liquid product after filtering the brown rice ferment), semi-solid (aqueous slurry), powder (lyophilized powder), granule or block (lyophilized block, or obtained by pressing), etc. (Edible product) The edible product according to the present invention contains the above brown rice ferment or is prepared from the above brown rice ferment. In some specific embodiments, in the edible product, the fermented brown rice product can be used in the form of a dry product, a solution or a slurry; preferably, it is used in the form of a dry product. These dry products usually have a moisture content of less than 3% by mass, preferably less than 2% by mass, and more preferably less than 1% by mass, and have a block or powder appearance. The edible product of the present invention may, in addition to the above-mentioned essential components, contain other optional ingredients in food, such as other plants or plant extracts (such as vegetables, fruits, grains, nuts, beans, etc. and their extracts), animal ingredients (such as animal meat products, animal dairy products, etc.), microbial ingredients (such as probiotics, prebiotics, etc.), functional added components (such as vitamin supplements, mineral supplements, unsaturated fatty acid supplements, etc.) and any food-acceptable auxiliary materials (such as stabilizers, thickeners, sweeteners, emulsifiers, antioxidants, pigments, etc.), etc., according to the needs of the final product, and such ingredients may be used in liquid, solid or semi-solid form. The present invention does not particularly limit the specific types of edible products, and may include oral preparations (e.g., tablets, powders, granules, capsules, oral liquids, etc.), animal milk-based products (e.g., liquid milk, milk powder, milk cubes, milk-containing beverages, etc.), plant milk-based products (plant protein beverages such as soy milk, soy yogurt, etc.), candies (e.g., gel candies, pressed candies, etc.), pasta products (e.g., bread, cakes, biscuits, noodles, steamed buns, steamed stuffed buns, dumplings, wontons, etc.), beverages (instant coffee, cereal powder, nut powder, lotus root powder, fruit and vegetable powder, etc.), etc. In principle, there is no particular limitation on the content of the fermented brown rice in the edible product. From the perspective of meeting nutritional requirements, complying with relevant laws and regulations, and having the desired effect of helping to moisten the intestines and promote bowel movements and / or helping to regulate intestinal flora, based on the total mass (dry weight) of the edible product, the content of the fermented brown rice is preferably 1 to 90% by mass. (Helps to moisturize the intestines and / or regulate intestinal flora) The present invention proposes for the first time that appropriate fermented brown rice can be used for moistening the intestines and facilitating bowel movements and regulating intestinal flora. Therefore, the edible product also has the effects of moistening the intestines and facilitating bowel movements and regulating intestinal flora. In some embodiments, the method of the present invention for helping to moisturize the intestine and promote bowel movements and / or regulate intestinal flora includes any one or more of the following: improving constipation, removing intestinal NO, downregulating the expression of NOS gene, increasing the abundance of beneficial intestinal bacteria and reducing the abundance of harmful intestinal bacteria. In some specific embodiments, the NOS gene includes any one or more of the nos1 gene, the nos2a gene and the nos2b gene. In some specific embodiments, the beneficial intestinal bacteria include probiotics of the phylum Bacteroidetes. In some specific embodiments, the harmful intestinal bacteria include any one or more of Firmicutes bacteria, Aeromonas bacteria, and Enterobacterales bacteria. The present invention helps to moisten the intestines and relieve constipation and / or regulate the intestinal flora, or improve constipation without the purpose of preventing and / or treating diseases. In addition, the edible product of the present invention is generally suitable for all populations, especially suitable for those who have a need for moistening the intestines and relieving constipation and / or regulating the intestinal flora, including but not limited to constipated people. For populations with different characteristics, the components in the edible product can also be adjusted accordingly. Examples To more clearly describe the technical solution of the present invention, it is further illustrated below with specific examples, but it cannot be used to limit the present invention. These are only partial examples of the present invention. Unless otherwise specified, the instruments, reagents, materials, experimental animals, etc. used in the present invention can be obtained through conventional commercial means. Example 1: Efficacy of freeze-dried powder of fermented brown rice in preventing constipation 1. Detection materials 1.1 Sample preparation information Freeze-dried powder sample of fermented brown rice: Brown rice was fully soaked in water and then steamed until the grains swelled, were hard on the outside and soft on the inside, and had no raw core. Then it was placed in a fermentation container, and 0.2% of the dry brown rice mass of Rhizopus powder (Angel Yeast Co., Ltd.) was added for fermentation (fermentation temperature 28°C, fermentation time 36 hours). The obtained fermented brown rice liquid was sterilized by steaming (temperature 100°C, steaming time 20 min). Finally, the sterilized fermented brown rice liquid was freeze-dried to obtain the freeze-dried powder of fermented brown rice. Unfermented brown rice powder sample: After the paddy was dehulled, the whole grain rice without processing was repeatedly ground by a rice milling machine and then broken into powder, and then collected through a 120-mesh sieve to obtain a powder with uniform texture. Freeze-dried powder solution of fermented brown rice: Prepared into a 20.0 mg / mL mother liquor with standard dilution water and used immediately. Unfermented brown rice powder solution: Prepared into a 20.0 mg / mL mother liquor with standard dilution water and used immediately. Positive control sample: Domperidone tablets (hereinafter referred to as domperidone), white tablets, batch number 190104499, Janssen Pharmaceutical Co., Ltd. of Xi'an, stored in a cool place. Prepared into a 10.0 mg / mL mother liquor with DMSO and stored at -20°C. 1.2 Experimental animals Zebrafish were all raised in fish-raising water at 28°C (Water quality: 200 mg of instant sea salt was added to every 1 L of reverse osmosis water, with a conductivity of 450 - 550 μS / cm; pH of 6.5 - 8.5; hardness of 50 - 100 mg / L CaCO 3 ), provided by the fish-raising center of Hangzhou Huante Biotechnology Co., Ltd. The experimental animal use license number was: SYXK(Zhe)2022 - 0004, and the feeding management met the requirements of international AAALAC accreditation (accreditation number: 001458). Wild-type AB strain zebrafish were bred by natural paired mating. Zebrafish at 5 days post-fertilization (5 dpf) were used for the determination of the maximum test concentration (MTC) of the freeze-dried powder of fermented brown rice for preventing constipation, the prevention of constipation, the improvement of constipation (NO scavenging), the evaluation of the effect on constipation-related genes, and the evaluation of the mechanism of regulating intestinal health. 1.3 Instruments, consumables and reagents Dissecting microscope (SZX7, OLYMPUS, Japan); CCD camera (VertA1, Shanghai Tusen Vision Technology Co., Ltd., China); Electrically focused continuous zoom fluorescence microscope (AZ100, Nikon, Japan); Precision electronic balance (CP214, OHAUS, USA); 6-well plate (Zhejiang Bellamber Biotechnology Co., Ltd., China); Ordinary PCR amplifier (T100, BIO-RAD, Singapore); Fluorescent quantitative PCR instrument (CFX Connect, BIO-RAD, Singapore); High-speed refrigerated centrifuge (Heraeus Fresco17, ThermoFisher, Germany); UV-visible spectrophotometer (Nanodrop 2000, Thermo, USA); Microwell plate mini centrifuge (BE-6100, Qilinbeier Instrument Manufacturing Co., Ltd., Haimen, China); Low-edge 96-well plate (transparent) (HSP9601, Bio-rad, USA). Methyl cellulose (batch number C2004046, Shanghai Aladdin Biochemical Technology Co., Ltd., China); Aluminum sulfate (batch number RH424739, Shanghai Yien Chemical Technology Co., Ltd., China); Dimethyl sulfoxide (DMSO, batch number BCCD8942, Sigma, Switzerland); Nile red (batch number SLBP9326V, Sigma, India); iTaq Universal SYBR Green Supermix (product number 1725124, Bio-rad, USA). 2. Evaluation method for the efficacy of preventing constipation Randomly select wild-type AB strain zebrafish at 5 dpf and randomly allocate them into 6-well plates, with 30 zebrafish in each well (experimental group). Administer freeze-dried powder of fermented brown rice (concentration shown in Table 1), unfermented brown rice powder at a concentration of 1000.0 μg / mL, and positive control domperidone at a concentration of 50.0 μg / mL by water solution. At the same time, set up a normal control group and a model control group, with a volume of 3 mL per well. After treatment at 28°C for 24 h, remove the freeze-dried powder of fermented brown rice and unfermented brown rice powder, and administer Nile red to stain the intestine in each experimental group by water solution. After the staining is completed, except for the normal control group, a constipation model is established by administering aluminum sulfate in water solution to the remaining experimental groups. After 6 h of aluminum sulfate treatment, randomly select 10 zebrafish from each group to take pictures and save the images under a fluorescence microscope, and analyze and collect data using NIS-Elements D 3.20 advanced image processing software. Analyze the fluorescence intensity of the zebrafish intestine, and evaluate the efficacy of the freeze-dried powder of fermented brown rice in preventing constipation based on the statistical analysis results of this index. The statistical processing results are expressed as mean±SE. Use SPSS 26.0 software for statistical analysis, and p<0.05 indicates that the difference is statistically significant. 3. Evaluation results of the efficacy in preventing constipation Under the conditions of this experiment, the freeze-dried powder of fermented brown rice has the efficacy in preventing constipation. The analysis results of the fluorescence intensity of the zebrafish intestine show (Table 1, Figure 1, Figure 2) that as the concentration of the administered sample gradually increases from 250 - 1000 μg / mL, the fluorescence intensity signal of the intestine shows a gradually decreasing phenomenon, and a good dose-effect relationship is presented. Among them, after the sample concentration rises to 655 μg / mL, compared with the constipation model group, the efficacy in preventing constipation has been significantly improved (p<0.001), indicating that the freeze-dried powder of fermented brown rice has the efficacy in preventing constipation, and the lowest effective concentration is 655 μg / mL. Unfermented brown rice powder shows no significant difference compared with the constipation model group. Table 1. Experimental results of the efficacy evaluation of the freeze-dried powder of fermented brown rice in preventing constipation (n = 10) Table note: Compared with the model control group, “***” in the table indicates p<0.001. Example 2: Efficacy of the freeze-dried powder of fermented brown rice in preventing constipation and scavenging NO 1. Detection materials 1.1 Sample preparation information Freeze-dried powder sample of fermented brown rice: The preparation method is the same as that in Example 1. Unfermented brown rice powder sample: The preparation method is the same as that in Example 1. Freeze-dried powder solution of fermented brown rice: The preparation method is the same as that in Example 1. Unfermented brown rice powder solution: The preparation method is the same as that in Example 1. Positive control sample: The preparation method is the same as that in Example 1. 1.2 Experimental animals Same as Example 1. 1.3 Instruments, Consumables and Reagents Dissecting microscope (SZX7, OLYMPUS, Japan); CCD camera (VertA1, Shanghai Tusen Vision Technology Co., Ltd., China); motorized focusing continuous zoom fluorescence microscope (AZ100, Nikon, Japan); precision electronic balance (CP214, OHAUS, USA); 6-well plate (Zhejiang Beranbo Biotechnology Co., Ltd., China); ordinary PCR amplifier (T100, BIO-RAD, Singapore); fluorescence quantitative PCR instrument (CFX Connect, BIO-RAD, Singapore); high-speed refrigerated centrifuge (Heraeus Fresco17, ThermoFisher, Germany); ultraviolet-visible spectrophotometer (Nanodrop 2000, Thermo, USA); microplate mini centrifuge (BE-6100, Qilinbeier Instrument Manufacturing Co., Ltd., Haimen, China); low-edge 96-well plate (transparent) (HSP9601, Bio-rad, USA); optical adhesive sealing film B (MSB1001, Bio-rad, USA). Methyl cellulose (batch number C2004046, Shanghai Aladdin Biochemical Technology Co., Ltd., China); aluminum sulfate (batch number RH424739, Shanghai Yian Chemical Technology Co., Ltd., China); dimethyl sulfoxide (DMSO, batch number BCCD8942, Sigma, Switzerland); nitric oxide detection probe (batch number D3308010, Yeasen Biotechnology (Shanghai) Co., Ltd., China)); Nile red (batch number SLBP9326V, Sigma, India). 2. NO Scavenging Efficacy Evaluation Method Wild-type AB strain zebrafish at 5 dpf were randomly selected and randomly assigned to 6-well plates, with 30 zebrafish in each well (experimental group). The freeze-dried powder of fermented brown rice was administered in water, with concentrations ranging from 250 to 1000 μg / mL (specific concentrations are shown in Table 2), the concentration of unfermented brown rice powder was 1000.0 μg / mL, and the concentration of the positive control domperidone was 50.0 μg / mL. At the same time, a normal control group and a model control group were set up, and the volume of each well was 3 mL. After treatment at 28 °C for 24 h, the freeze-dried powder of fermented brown rice and unfermented brown rice powder were removed. Except for the normal control group, aluminum sulfate was administered in water to the remaining experimental groups to establish a constipation model. After treatment at 28 °C for 6 h, staining was performed with a NO fluorescence kit. After staining, 10 zebrafish were randomly selected from each group, photographed under a fluorescence microscope, and the pictures were saved. Data were analyzed and collected using NIS-Elements D 3.20 advanced image processing software, and the NO fluorescence intensity in the zebrafish intestine was analyzed. The efficacy of the freeze-dried powder of fermented brown rice in preventing constipation (NO scavenging) was evaluated based on the statistical analysis results of this index. The statistical treatment results were expressed as mean ± SE. Statistical analysis was performed using SPSS 26.0 software, and p < 0.05 indicated that the difference was statistically significant. 3. Evaluation results of NO scavenging efficacy From the NO fluorescence intensity in the zebrafish intestine, it can be seen that when the sample concentration was from 500 to 1000 μg / mL, compared with the model control signal, the NO fluorescence intensity signal in the intestine decreased, and the signal intensity gradually decreased with the increase in the sample concentration. This indicates that the freeze-dried powder of fermented brown rice has NO scavenging efficacy, and compared with the model control, it shows a good dose-effect relationship. Compared with the fermented brown rice, the unfermented brown rice powder did not show a highly significant difference compared with the model control group, indicating that the fermented brown rice can better scavenge the NO fluorescence signal intensity. See Table 2, Figures 3 and 4 for details. Table 2. Evaluation experimental results of the efficacy of the freeze-dried powder of fermented brown rice in improving constipation (NO scavenging) (n = 10) Table note: Compared with the model control group, “***” in the table indicates p < 0.001. Example 3: Effects of the freeze-dried powder of fermented brown rice on constipation-related genes 1. Detection materials 1.1 Sample preparation information Freeze-dried powder sample of fermented brown rice: The preparation method was the same as in Example 1. Unfermented brown rice powder sample: The preparation method was the same as in Example 1. Freeze-dried powder solution of fermented brown rice: The preparation method was the same as in Example 1. Unfermented brown rice powder solution: The preparation method was the same as in Example 1. Positive control sample: The preparation method was the same as in Example 1. 1.2 Experimental animals Same as Example 1. 1.3 Instruments, Consumables and Reagents Dissecting microscope (SZX7, OLYMPUS, Japan); CCD camera (VertA1, Shanghai Tusen Vision Technology Co., Ltd., China); motorized focusing continuous zoom fluorescence microscope (AZ100, Nikon, Japan); precision electronic balance (CP214, OHAUS, USA); 6-well plate (Zhejiang Bellamber Biotechnology Co., Ltd., China); ordinary PCR amplifier (T100, BIO-RAD, Singapore); fluorescence quantitative PCR instrument (CFX Connect, BIO-RAD, Singapore); high-speed refrigerated centrifuge (Heraeus Fresco17, ThermoFisher, Germany); ultraviolet-visible spectrophotometer (Nanodrop 2000, Thermo, USA); microplate mini centrifuge (BE-6100, Qilinbeier Instrument Manufacturing Co., Ltd., Haimen, China); low-profile skirt 96-well plate (transparent) (HSP9601, Bio-rad, USA); optical adhesive sealing film B (MSB1001, Bio-rad, USA); automatic sample rapid grinder (JXFSTPRP-24L, Shanghai Jingxin Experimental Equipment Technology Department, China); automatic nucleic acid extractor (Auto-Pure32A, Hangzhou Ausheng Instrument Co., Ltd., China). Methyl cellulose (batch number C2004046, Shanghai Aladdin Biochemical Technology Co., Ltd., China); aluminum sulfate (batch number RH424739, Shanghai E&G Chemical Technology Co., Ltd., China); dimethyl sulfoxide (DMSO, batch number BCCD8942, Sigma, Switzerland); nitric oxide detection probe (batch number D3308010, Yeasen Biotechnology (Shanghai) Co., Ltd., China)); Nile red (batch number SLBP9326V, Sigma, India); iTaq Universal SYBR Green Supermix (product number 1725124, Bio-rad, USA); FastKing cDNA First Strand Synthesis Kit (genome-free) (batch number X0320, Tiangen Biochemical Technology (Beijing) Co., Ltd., China); Universal RNA Extraction TL Kit C (product number TL2204001643C, Foshan Aowei Biotechnology Co., Ltd., China). 2. Evaluation method for the influence on constipation-related genes First, after the sample treatment was completed, the total RNA of zebrafish was extracted, and the concentration of RNA and the A260 / A280 ratio were measured using an ultraviolet-visible spectrophotometer (Table 3) to evaluate the quality of the total RNA of zebrafish. Subsequently, the primer sequence information was determined: Wild-type AB strain zebrafish at 5 dpf were randomly selected and randomly assigned to 6-well plates, with 30 zebrafish in each well (experimental group). The freeze-dried powder of fermented brown rice and unfermented brown rice powder (both at a concentration of 1000 μg / mL) were administered by water solution, and domperidone at a concentration of 50.0 μg / mL was used as the positive control. At the same time, a normal control group and a model control group were set up, and the volume of each well was 3 mL. After treatment at 28 °C for 24 h, the freeze-dried powder of fermented brown rice and unfermented brown rice powder were removed. Except for the normal control group, aluminum sulfate was administered by water solution to the remaining experimental groups to establish a constipation model. After treatment at 28 °C for 6 h, the total RNA of zebrafish in each group was extracted using an automatic nucleic acid extractor, and the concentration and purity of the total RNA were measured using an ultraviolet-visible spectrophotometer. 2.00 μg of the total RNA of the zebrafish sample was taken, and cDNA was synthesized according to the instructions of the cDNA first-strand synthesis kit to obtain 20.0 μL of cDNA. The expressions of β-actin, nos1, nos2a, and nos2b genes were detected by q-PCR. β-actin was used as the internal reference for gene expression, and the relative RNA expression levels of nos1, nos2a, and nos2b genes were calculated. The results of statistical processing were expressed as mean±SE. Statistical analysis was performed using SPSS 26.0 software, and p<0.05 indicated that the difference was statistically significant. 3. Evaluation results of the effects on constipation-related genes 3.1 RNA extraction results and primer sequence information After the sample treatment was completed, the total RNA of zebrafish was extracted, and the results of the concentration of RNA and the A260 / A280 ratio measured using an ultraviolet-visible spectrophotometer are shown in Table 3. The A260 / A280 ratios were all between 1.8 and 2.2, indicating that the quality of the total RNA of zebrafish extracted was good and could be used for subsequent q-PCR experiments. The primer sequences are shown in Table 4. Table 3. Concentration of total RNA and A260 / A280 ratio (n = 3) Table 4. Primer sequence information 3.2 Effects on constipation-related genes Total RNA of zebrafish samples was used to detect the expression of constipation-related nos1, nos2a, and nos2b genes by q-PCR according to the cDNA first-strand synthesis kit. The results showed that the freeze-dried powder of fermented brown rice could downregulate the relative expression levels of nos1, nos2a, and nos2b genes. Compared with the fermented brown rice powder, the unfermented brown rice powder did not show a significant difference compared with the model control group, indicating that fermented brown rice could significantly reduce the relative expression levels of nos1 and nos2b genes. See Table 5 and Figures 5-7 for details. Table 5. Experimental results of the effect of freeze-dried powder of fermented brown rice on constipation-related genes (n = 3) Table note: Compared with the model control group, *p < 0.05, **p < 0.01, ***p < 0.001. Example 4: Evaluation of the freeze-dried powder of fermented brown rice on the intestinal flora 16S rRNA 1. Detection materials 1.1. Sample preparation information Freeze-dried powder sample of fermented brown rice: The preparation method is the same as that in Example 1. Freeze-dried powder solution of fermented brown rice: The preparation method is the same as that in Example 1. 1.2. Experimental animals Zebrafish were all raised in fish-raising water at 28°C (water quality: 200 mg of instant sea salt was added to every 1 L of reverse osmosis water, the conductivity was 450-550 μS / cm; the pH was 6.5-8.5; the hardness was 50-100 mg / L CaCO 3 )), provided by the fish-raising center of our company, and the experimental animal use license number was: SYXK(Zhe)2022-0004, and the feeding management met the requirements of international AAALAC certification (certification number: 001458). Wild-type AB strain zebrafish were used for natural paired mating and reproduction. Zebrafish at the age of 5 dpf were used for the evaluation of the mechanism of the freeze-dried powder of fermented brown rice in regulating intestinal health. 1.3. Instruments, consumables, and reagents Dissecting microscope (SZX7, OLYMPUS, Japan); Precision electronic balance (CP214, OHAUS, USA); 6-well plate (Zhejiang Beilamber Biotechnology Co., Ltd., China); Microplate reader (synergy HTX, GeneCompang Limited, China); Instant centrifuge (OSE-MC8, Tiangen Biochemical Technology (Beijing) Co., Ltd., China); Vortex oscillator (vortex-2G560E, SCIENTIFIC INDUSTRIES.INC, USA); Gradient gene amplifier (veriti96well9902, Appliedbiosystem, USA). Aluminum sulfate (batch number RH424739, Shanghai Yien Chemical Technology Co., Ltd., China); TGuide S96 Magnetic Soil / Fecal DNA Kit (DP812, Tiangen Biotech Co., Ltd., China); KOD FX Neo (TOYOBO) (KFX-201S, Beijing Bailingke Biotechnology Co., Ltd., China); TransStart FastPfu Fly DNA Polymerase (AP231-12, Beijing TransGen Biotech Co., Ltd., China); Phusion HF MM (M0544L, Beijing Bailingke Biotechnology Co., Ltd., China); VAHTSTM DNA Clean Beads (N411-03, Nanjing Novoprotein Science & Technology Co., Ltd., China). 2. Evaluation method of intestinal flora 16S rRNA Wild-type AB strain zebrafish at 5 dpf were randomly selected and randomly assigned to 6-well plates, with 30 zebrafish in each well (experimental group), and the volume of each well was 3 mL. 10 biological replicates were set up in parallel. The freeze-dried powder of brown rice fermented product was administered at a concentration of 1000 μg / mL in water, and at the same time, a normal control group (blank control group) and a model control group were set up, with the volume of each well being 3 mL. After treatment at 28 °C for 24 h, the freeze-dried powder of brown rice fermented product was removed. Except for the normal control group, aluminum sulfate was administered in water to the remaining experimental groups to establish a constipation model. After 6 h of aluminum sulfate treatment, the liquid medicine was washed off with ultrapure water in each experimental group, and then immediately transferred into 1.5 mL EP tubes (100 tails / tube), the liquid was sucked out, and liquid nitrogen was immediately poured in for 3 min and stored at -80 °C for subsequent detection of intestinal flora 16S rRNA. The main steps of 16S rRNA detection include: 1) Sequencing data quality assessment (ASVs analysis): The collected samples are subjected to DNA extraction, quality detection, and sequencing quality assessment. First, Trimmomatic is used to perform quality filtering on the raw data, then Cutadapt is used to identify and remove primer sequences, and subsequently USEARCH is used to splice paired-end reads and remove chimeras to finally obtain high-quality sequences for subsequent analysis. The quality assessment is based on the Labchip Touch platform. Through an automated analysis and determination process, Labchip can automatically identify the main peak, perform smear analysis on the peak graph, and determine whether the sequencing data quality is qualified. If qualified, it can be used for subsequent library construction. 2) Analysis of intestinal flora species diversity (α-diversity analysis): The Shannon index is calculated using the mothur software; the Simpson index is calculated using the Simpson diversity index formula. Under the condition of the same species richness, the greater the evenness of each species in the community, the greater the diversity of the community is considered. The larger the Shannon index value and the Simpson index value, the higher the species diversity of the sample. 3) Analysis of differences in microbial communities among groups (β-diversity analysis): Principal component analysis (PCA), principal coordinates analysis (PCoA), and analysis of the correlation between environmental factors and sample composition (RDA / CCA) are plotted based on the R language platform. 3. Evaluation results of intestinal flora 16S rRNA 3.1 Analysis of intestinal flora species diversity As shown in Figures 8A - 8B, compared with the normal control group, the simpson index and shannoneven index of the model control group decreased (p < 0.05), indicating that the species diversity of the intestinal flora in constipated zebrafish decreased, which had an impact on species richness and evenness; compared with the model control group, the simpson index and shannoneven index of the sample group increased (p < 0.05), indicating that after sample intervention, the species diversity of the intestinal flora in zebrafish increased, and it had a role in callback to the normal control group for species richness and evenness. The above results indicate that sample intervention can callback the species richness of the intestinal flora in constipated zebrafish and has a certain impact on species evenness and diversity. 3.2 Analysis of differences in microbial communities among groups As shown in Figures 9, 10, and 11, principal component analysis (PCA), principal coordinates analysis (PCoA), and non-metric multidimensional scaling (NMDS) based on operational taxonomic units (OTUs) were used to evaluate the differences between microbial communities in each group. Each point in the figure represents a sample; different colors represent different groups; the oval circles indicate that they are 95% confidence ellipses (i.e., if there are 100 samples in this sample group, 95 of them will fall within it). The results show that the samples within each group can be significantly clustered, indicating that the intestinal flora within each group of samples tends to be consistent; there are differences in the microbial community structure between the normal control group and the model control group, indicating that the intestinal flora structure of constipated zebrafish is disordered; the intestinal flora structure of the sample group deviates from that of the model control group, indicating that the intestinal flora structure of constipated zebrafish has changed after sample intervention. 3.3 Analysis of species composition at different taxonomic levels As shown in Figure 12, at the phylum level, compared with the normal control group, the abundances of Proteobacteria and Bacteroidota decreased in the samples of the model control group; the abundances of Firmicutes and Actinobacteriota increased; sample intervention had no callback effect on Proteobacteria, but could increase the abundance of Bacteroidota and decrease the abundances of Firmicutes and Actinobacteriota. As shown in Figure 13, at the order level, compared with the normal control group, the abundance of Enterobacterales increased in the samples of the model control group; sample intervention could reduce the abundance of Enterobacterales. As shown in Figure 14, at the genus level, compared with the normal control group, the abundance of Aeromonas increased in the samples of the model control group; sample intervention could reduce the abundance of Aeromonas. The results of the changes in the composition of intestinal microorganisms at the phylum, order, and genus levels in each group indicate that the intestinal flora composition is specific among groups. Sample intervention can callback the abundances of beneficial bacteria (Bacteroidota) and harmful bacteria (Firmicutes, Enterobacterales, Aeromonas) in the intestinal flora of zebrafish, manifested as increasing the abundance of Bacteroidota and decreasing the abundances of Firmicutes, Aeromonas, and Enterobacterales. 3.4 Analysis of differences in species composition among groups Linear discriminant analysis effect size (LEfSe) was used to compare multiple groups. According to the ranking of the linear discriminant analysis value (LDA score ≥ 2), the species with significant differences in abundance between groups were found. The characteristic flora refers to: in the three groups of experiments of the normal control group (blank control group), model control group, and sample group of a certain bacterium, the one with the highest LDA value was determined as the characteristic flora of this group of experiments. Thus, the characteristic flora of the normal control group are Methylolbacterium, Beijerinckiaceae, etc.; the characteristic flora of the model control group are Gammaproteobacteria, Enterobacterales, Aeromonas, etc.; the characteristic flora of the sample group are Bacteroidota, Rhizobiales, etc. The results are shown in Figures 15 - 17C. Application Example In the following application examples, methods for making several foods and health products using the fermented brown rice product are provided. However, it cannot be used to limit the present invention, and this is only part of the application examples of the present invention. Unless otherwise specified, the instruments, materials, edible raw materials, etc. used in the present invention can be obtained through conventional commercial means. Among them, the preparation method of the freeze-dried powder of the fermented brown rice product is the same as that in the above-mentioned embodiment. "Parts" are all parts by weight, and the percentage content of the components is all percentage by weight. Application Example 1 A soy milk drink containing the freeze-dried powder of the fermented brown rice product, and every 1000 parts of the soy milk drink are prepared from the following components by weight: The raw materials used in the soy milk drink of the present invention are: 670 parts of purified water, 200 parts of soybeans, 80 parts of the freeze-dried powder of the fermented brown rice product, 5 parts of hemp seeds, 30 parts of xylitol, and 15 parts of cereal powder; 200 parts of soybeans are washed, after high-temperature cooking, 80 parts of the freeze-dried powder of the fermented brown rice product and 5 parts of hemp seeds are added and ground into a slurry together, homogenized (600 / 120 bar), 30 parts of xylitol and 15 parts of cereal powder are added for flavoring, then 670 parts of purified water are added for standardization, mixed evenly and then homogenized again (600 / 120 bar), cooled and sterilized by UHT at 140 - 145 °C / 4 - 6 s, and aseptically filled into brown rice enzyme soy milk. The content of the freeze-dried powder of the fermented brown rice product in the product is 8%. Application Example 2 A freeze-dried milk block containing the freeze-dried powder of the fermented brown rice product, and every 1000 parts of the freeze-dried milk block are prepared from the following components by weight: The raw materials used for the freeze-dried milk cubes of the present invention are: 500 parts of purified water, 150 parts of milk powder, 250 parts of freeze-dried powder of fermented brown rice, 90 parts of granulated sugar, and 10 parts of citric acid; the above raw materials are mixed and stirred for 25 minutes, and the mixture is sterilized by ultra-high pressure treatment. After cooling, the mixture is poured into a mold, and a spatula is used to evenly spread the solution for dish laying. The mixture is placed at -80°C for quick freezing for 12 hours, and the quick-frozen mixture solid is put into a vacuum freeze dryer, and the freeze-drying time is 24 hours. Packaging gives the final product. The freeze-dried powder of fermented brown rice in the product is 25%. Application Example 3 Triangular milk cubes containing freeze-dried powder of fermented brown rice, and every 1000 parts of triangular milk cubes are prepared from the following components in parts by weight: The raw materials used for the triangular milk cubes of the present invention are: 250 parts of whole milk powder, 200 parts of isomaltooligosaccharide, 200 parts of cheese, 160 parts of freeze-dried powder of fermented brown rice, 80 parts of butter, 50 parts of purified water, 40 parts of cream, and 20 parts of emulsifying salt; 250 parts of whole milk powder, 200 parts of isomaltooligosaccharide, 200 parts of cheese, 160 parts of freeze-dried powder of fermented brown rice, and 20 parts of emulsifying salt are pre-mixed evenly; the pre-mixed materials are mixed with 80 parts of butter, 50 parts of purified water, and 40 parts of cream, stirred and heated to 85-95°C, kept warm and stirred for emulsification, and then the above materials are quickly cooled, shaped into sheets, sterilized by microwave sterilization method, and packaged and refrigerated after sterilization to obtain the final product. The freeze-dried powder of fermented brown rice in the product is 16%. Application Example 4 Milk-containing beverage containing freeze-dried powder of fermented brown rice, and every 1000 parts of milk-containing beverage are prepared from the following components in parts by weight: The raw materials used for the milk-containing beverage of the present invention are: 600 parts of purified water, 200 parts of lactic acid bacteria fermentation broth, 100 parts of fruit and vegetable juice, 60 parts of stevioside, 20 parts of freeze-dried powder of fermented brown rice, 10 parts of pectin, and 10 parts of L-ascorbic acid; the above raw materials are mixed evenly and subjected to homogenization treatment, and the homogenized liquid is sterilized by a sterilizer; the sterilized liquid is aseptically filled into a package to obtain the final product. The freeze-dried powder of fermented brown rice in the product is 2%. Application Example 5 Formula milk powder containing freeze-dried powder of fermented brown rice, and every 1000 parts of formula milk powder are prepared from the following components in parts by weight: The raw materials used for the formula milk powder of the present invention are: 350 parts of skimmed milk powder, 260 parts of whole milk powder, 300 parts of demineralized whey powder, 50 parts of freeze-dried powder of fermented brown rice, 6 parts of lecithin, 4 parts of docosahexaenoic acid, 5 parts of arachidonic acid, 5 parts of taurine, 6 parts of phosphatidylserine, 4 parts of tryptophan, 5 parts of lysine, 2 parts of compound prebiotics, 1 part of compound vitamins, and 2 parts of compound minerals; the above raw materials are mixed evenly, and in a sterile environment, the materials after sufficient multi-dimensional mixing are filled with nitrogen and packaged to obtain the final product. The freeze-dried powder of fermented brown rice in the product is 5%. Application Example 6 Hard capsules containing freeze-dried powder of fermented brown rice. Every 1000 parts of the hard capsules are prepared from the following components by weight: The raw materials used for the hard capsules of the present invention are: 800 parts of freeze-dried powder of fermented brown rice, 160 parts of microcrystalline cellulose, and 20 parts of magnesium stearate. After mixing the above raw materials evenly, they are filled into gelatin capsule shells (the capsule shells are mainly gelatin, and the proportion of gelatin is 20 parts), and then packaged to obtain the final product. The freeze-dried powder of fermented brown rice accounts for 80% in the product. Application Example 7 Dry powder supplements or solid beverages containing freeze-dried powder of fermented brown rice. Every 1000 parts of the dry powder supplements or solid beverages are prepared from the following components by weight: The raw materials used for the dry powder supplements or solid beverages of the present invention are: 345 parts of isomaltooligosaccharide, 160 parts of resistant dextrin, 80 parts of fructooligosaccharide, 400 parts of freeze-dried powder of fermented brown rice, 5 parts of Bifidobacterium lactis (BB-12), 4 parts of Bifidobacterium lactis (HN019), and 6 parts of Lactobacillus rhamnosus (HN001). After mixing the above raw materials evenly, in a sterile environment, after sufficient dry mixing, the solid beverage powder after mixing evenly is filled with nitrogen and packaged to obtain the final product. The freeze-dried powder of fermented brown rice accounts for 40% in the product. Application Example 8 Tablet supplements or chewable candies containing freeze-dried powder of fermented brown rice. Every 1000 parts of the tablet supplements or chewable candies are prepared from the following components by weight: The raw materials used for the tablet supplements or chewable candies of the present invention are: 220 parts of isomaltooligosaccharide, 100 parts of comprehensive fruit and vegetable powder, 500 parts of freeze-dried powder of fermented brown rice, 50 parts of mixed fruit and vegetable enzymes, 40 parts of cassia seed powder, 30 parts of lotus leaf powder, 25 parts of aloe vera powder, and 15 parts of stevioside. After mixing the above raw materials evenly, through granulation, drying, sieving, and mixing with 20 parts of excipients (the excipients are a mixture of microcrystalline cellulose, magnesium stearate, and silicon dioxide), with or without adding essence, it is pressed into semi-finished products, and the semi-finished product granules are coated and packaged to obtain the final product. The freeze-dried powder of fermented brown rice accounts for 50% in the product. Application Example 9 Compound fruit and vegetable powder containing freeze-dried powder of fermented brown rice. Every 1000 parts of the compound fruit and vegetable powder are prepared from the following components by weight: The raw materials used in the compound fruit and vegetable powder of the present invention are: 300 parts of freeze-dried powder of fermented brown rice, 160 parts of pears, 140 parts of cabbages, 100 parts of corns, 100 parts of apples, 50 parts of spinach, 50 parts of carrots, 50 parts of melons, and 50 parts of broccoli; after washing the above-mentioned fruit and vegetable raw materials and cutting them into pieces, 140 parts of cabbages, 100 parts of corns, 50 parts of spinach, 50 parts of carrots, and 50 parts of broccoli are first placed in a steamer and steamed for 10 minutes, and then are ground into vegetable juice together with 160 parts of pears, 100 parts of apples, and 50 parts of melons. 300 parts of freeze-dried powder of fermented brown rice are mixed evenly with the vegetable juice and then steamed for 10 minutes to obtain a concentrated liquid, and the concentrated liquid is spray-dried to obtain the final product. The freeze-dried powder of fermented brown rice in the product is 30%. Industrial applicability The use of the fermented brown rice provided by the present invention can be widely applied in the fields of food or health food, etc.

Claims

1. Use of fermented brown rice in preparing food that helps to moisten the intestines and promote bowel movements and / or helps to regulate intestinal flora, characterized in that: The preparation method of the brown rice fermented product comprises the following steps: Inoculation step: placing brown rice in a fermentation container, adding 0.1-1% of the mass of dry brown rice fermentation bacteria; Fermentation step: Fermentation is performed after the fermentation container is sealed, wherein the fermentation temperature is 22-37° C. and the fermentation time is 30-45 hours.

2. The use according to claim 1, characterized in that The brown rice is processed by the following steps: Cooking steps: Steam the rice until the rice grains are puffy, hard on the outside and soft on the inside, with no raw core.

3. The use according to claim 1 or 2, characterized in that: The fermentation container is configured such that the volume of the container is 10 to 50 L per 1 kg of dry brown rice, and the thickness of the brown rice in the container does not exceed 20 cm.

4. The use according to any one of claims 1 to 3, characterized in that: The fermentation bacteria include Rhizopus.

5. The use according to any one of claims 1 to 4, characterized in that: The method for helping to moisten the intestine and promote bowel movements and / or regulate intestinal flora includes any one or more of the following: improving constipation, removing intestinal NO, downregulating the expression of NOS gene, increasing the abundance of beneficial intestinal bacteria and reducing the abundance of harmful intestinal bacteria.

6. The use according to claim 5, characterized in that The NOS gene includes any one or more of nos1 gene, nos2a gene and nos2b gene.

7. The use according to claim 5 or 6, characterized in that The beneficial intestinal bacteria include probiotics from the phylum Bacteroidetes.

8. The use according to any one of claims 5 to 7, characterized in that: The harmful intestinal bacteria include any one or more of Firmicutes bacteria, Aeromonas bacteria and Enterobacteriales bacteria.

9. A use of an edible product to help moisturize the intestines and promote bowel movements and / or to help regulate intestinal flora, characterized in that: The edible product comprises the fermented brown rice as defined in any one of claims 1 to 8 or is prepared from the fermented brown rice as defined in any one of claims 1 to 8.

10. The use according to claim 9, characterized in that The content of the fermented brown rice product is 1 to 90% by mass based on the total mass of the edible product.

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