Plant source organic selenium cat food with immune regulation function

Abstract

The invention discloses a botanical organic selenium cat food with an immune regulation function. According to the cat food, yeast beta-glucan, lactoferrin and plant source organic selenium are added on the basis of basic cat food, the addition amount of the yeast beta-glucan is 300-500 mg / kg, the addition amount of the lactoferrin is 100-150 mg / kg, the total selenium content in the cat food is 0.4-0.5 mg / kg, and the organic selenium accounts for 80-90% of the total selenium content. The plant source organic selenium exists in a form of combining seleno-amino acid with protein. Through the synergistic compatibility of various immune function factors, the immune regulation function of the cat food is improved on the premise of ensuring the safety and the stability, and the cat food is suitable for the field of functional pet food.

Description

Technical Field

[0001] This invention relates to a functional cat food prepared by adding plant-derived organic selenium, which can improve the cat's immune activity and enhance the body's resistance to stress and infection, belonging to the field of pet food and functional feed technology. Background Technology

[0002] With the continued growth in the number of pet owners, cat health management is gradually shifting from simply meeting basic nutritional needs to functional and precise nutritional interventions. Among these, recurrent infections, increased stress responses, and chronic inflammation caused by weakened immune function have become significant factors affecting cat health and lifespan. Therefore, developing cat food products with immune-regulating functions is of great practical importance.

[0003] Selenium is an essential trace element for maintaining the body's immune function and antioxidant defense system. It participates in the synthesis of various selenoproteins and antioxidant enzymes, playing a key role in regulating immune cell activity, inhibiting inflammatory responses, and scavenging free radicals. Currently, some cat food products supplement selenium by adding inorganic selenium or chemically synthesized selenium sources. However, inorganic selenium has problems such as low bioavailability, unstable metabolism in vivo, narrow dosage window, and the potential for toxic side effects from excessive dosage, which limits its safe application in functional pet foods.

[0004] In contrast, plant-derived organic selenium typically exists in the form of selenoamino acids or selenium-binding proteins, which are closer to the form of natural dietary selenium and have advantages such as high absorption efficiency, good safety, and strong sustained-release properties in the body. However, there are still few studies and products that apply plant-derived organic selenium systems to cat food, and most products only focus on "nutritional supplementation," lacking targeted formulation design and stable addition methods around immune regulation functions, making it difficult to fully realize the potential advantages of plant-derived organic selenium in immune regulation. In addition, cats, as strict carnivores, have unique tolerance and metabolic characteristics to micronutrients. How to achieve the stable existence, uniform dispersion, and effective bioavailability of plant-derived organic selenium in cat food while ensuring palatability and safety remains a pressing technical problem to be solved in the current pet food industry.

[0005] Therefore, it is necessary to provide a safe, stable cat food product with plant-derived organic selenium as its core function and a clear immune-regulating effect, in order to make up for the shortcomings of existing technologies and enhance the functional value and health benefits of cat food. Summary of the Invention

[0006] This invention provides a cat food with immunomodulatory functions and its application, aiming to improve the immune activity of cats, enhance their stress resistance, and maintain their overall health through a combination of specific functional components. Its key feature is the addition of immune-functional components to a basic cat food diet. These components include yeast β-glucan, lactoferrin, and plant-derived organic selenium, wherein:

[0007] The addition amount of yeast β-glucan is 300–500 mg / kg;

[0008] The amount of lactoferrin added is 100–150 mg / kg;

[0009] The total selenium content in cat food is 0.4–0.5 mg / kg, and organic selenium accounts for 80–90% of the total selenium content.

[0010] The cat food as described in claim 1 is characterized in that the yeast β-glucan is derived from the cell wall of Saccharomyces cerevisiae or Kluyveromyces martensii, and its structural feature is a high molecular weight polysaccharide composed of a β-1,3-glucan backbone and β-1,6-glucan side chains.

[0011] The cat food as described in claim 1, wherein the lactoferrin is food-grade or feed-grade lactoferrin.

[0012] The cat food as described in claim 1 is characterized in that the plant-derived organic selenium is selected from one or more of the following: selenium-enriched plant protein, selenium-enriched grain extract, and selenium-enriched vegetable extract.

[0013] The cat food as described in claim 1 is characterized in that the selenium in the plant-derived organic selenium mainly exists in the form of selenomethionine, selenocysteine, methylselenocysteine ​​combined with protein or polypeptide.

[0014] The cat food as described in claim 1 is characterized in that the cat food base includes animal protein raw materials, carbohydrate raw materials, fat raw materials, dietary fiber, and vitamin and mineral premix.

[0015] The cat food as described in claim 1 is characterized in that the yeast β-glucan, lactoferrin and plant-derived organic selenium are added to the cat food by mixing or adding them in stages.

[0016] The cat food as described in claim 1, characterized in that the cat food is extruded dry food, semi-moist food, or freeze-dried compound cat food. The application of the cat food as described in any one of claims 1-9 in improving feline immune activity, enhancing stress resistance, and maintaining overall health.

[0017] Beneficial effects:

[0018] This invention, by scientifically combining yeast beta-glucan, lactoferrin, and plant-derived organic selenium with conventional cat food, utilizes the synergistic effect of multiple immune-active components to meet the daily nutritional needs of cats while enhancing their immune activity and stress resistance, thus helping to maintain their overall health. It offers the following beneficial effects:

[0019] (1) By synergistically adding yeast β-glucan, lactoferrin and plant-derived organic selenium to the basic cat food, the body's immune function can be regulated through multiple pathways, the activity of immune cells can be enhanced, and the overall immune level of the body can be improved. Its immune regulation effect is better than that of cat food with a single functional factor added.

[0020] (2) Plant-derived organic selenium, under the condition that the total selenium content is controlled at 0.4–0.5 mg / kg and the proportion of organic selenium reaches 80–90%, takes into account both safety and high bioavailability, significantly reduces the safety risks caused by excessive selenium, and is suitable for long-term feeding.

[0021] (3) The cat food of the present invention can help maintain the health and physiological homeostasis of cats by improving antioxidant capacity and reducing stress response level, providing clear support for the immune regulation function of functional cat food products, and has good application prospects and market value. Attached Figure Description

[0022] Figure 1 This invention relates to the effects of cat food on cat food intake and weight gain rate in Examples 1 and 1 of the present invention. Detailed Implementation

[0023] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explanation of the present invention and are not intended to limit the present invention.

[0024] The measurement methods involved in the examples are as follows:

[0025] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the embodiments are for better explanation of the present invention and are not intended to limit the present invention.

[0026] In the following embodiments, the measurements were performed according to the following methods:

[0027] 1. Method for determining total selenium

[0028] Take 0.1–0.2 g of sample into a microwave digestion tube, add 3.5 mL of concentrated nitric acid, and digest overnight in a cold environment. Then add 5.0 mL of ultrapure water, seal the tube with both inner and outer stoppers, and proceed with microwave digestion. After the program is complete, dilute the digested solution to the appropriate volume with ultrapure water and mix thoroughly. Take approximately 15 mL of the solution, pass it through a 0.22 μm nylon membrane, and place it in a 15 mL centrifuge tube. Perform a reagent blank simultaneously.

[0029] Total selenium was determined using an iCAP TQ inductively coupled plasma mass spectrometer in TQ-O2 reaction mode. 80 Se isotopes were monitored by the instrument, and the sampling cone was a nickel cone. A pig liver standard (selenium content 1.54 ± 0.29 mg / kg) was used as the quality control sample for total selenium determination. A series of standard solutions were prepared, and the selenium content was calculated using the external standard method.

[0030] The formula for calculating selenium content is:

[0031] Where X: selenium content of the sample (mg / kg); C: selenium concentration measured after sample digestion and volume adjustment (μg / L); K: dilution factor; V: volume of sample after digestion and volume adjustment (mL); M: amount of digested sample (g).

[0032] 2. Methods for determining selenium speciation

[0033] The content of organic selenium forms was determined by HPLC-ICP MS.

[0034] 1) Sample pretreatment:

[0035] Take 100 mg of sample into a 20 mL sealed hydrolysis flask. Add 5% w / w alkaline protease (purchased from DUPONT, enzyme activity ≥580000 DU / g), 5% w / w trypsin (purchased from Hefei Bomei Biotechnology Co., Ltd., enzyme activity ≥250 NFU / mg), and 5% w / w proteinase K (purchased from Hefei Bomei Biotechnology Co., Ltd., enzyme activity ≥40 U / mg) sequentially to each flask. Then add 15 mL of 30 mmol / L Tris-HCl (pH 8.5). Stir magnetically at 45 ℃ and 400 rpm for 4 h. After reaction, collect the enzymatic hydrolysate, filter it through a 0.22 μm aqueous membrane, and inject it into the sample.

[0036] 2) HPLC chromatographic conditions:

[0037] The chromatographic column was a TechMate C18-ST reversed-phase column (4.6 mm × 250 mm, 5 μm); the mobile phase was a 30 mmol / L diammonium hydrogen phosphate solution containing 0.5 mmol / L tetrabutylammonium hydroxide and 3.0% (v / v) methanol, and the pH of the mobile phase was adjusted to 6.0 with 10% formic acid. Isocratic elution was performed at a flow rate of 1.0 mL / min, the column temperature was 30 ℃, and the injection volume was 10 μL.

[0038] The ICP-MS conditions are shown in Table 2. A nickel cone with a high-sensitivity pad was used. The measurement mode was TQ-O2 mode, and the isotope sites were collected as follows: 80 Se, the dwell time is 0.05 s.

[0039] The contents of five selenium forms in the sample, namely methylselenocysteine ​​(MeSeCys), selenomethionine (SeMet), selenocysteine ​​(SeCys2), tetravalent selenium (Se(IV)), and hexavalent selenium (Se(VI)), were calculated using the external standard method.

[0040] 3. Growth performance

[0041] The mental state of the experimental cats was observed during the experiment. Food intake was measured on days 1, 10, 20, and 30 of the formal experiment, and the feed intake rate was calculated according to formula (1):

[0042] The weight of each group of experimental cats was measured on days 1, 10, 20 and 30 of the formal experiment, and their weight growth rate was calculated according to formula (2).

[0043] 4. Animal feeding and indicator testing

[0044] Five healthy adult cats of the same breed and similar weight were selected for each group. Before the experiment, all cats were fed standard commercial cat food for one week. After the acclimatization period, they were fed different experimental group cat foods for 30 days. All cats were housed individually in cages, and all groups were kept under the same feeding and management conditions, with adequate room temperature and ventilation. They were fed regularly each day, with free access to food and water. The living environment and equipment were cleaned and disinfected daily, and the cages were thoroughly cleaned.

[0045] 1) Blood sample collection: On day 1 and day 30 of the formal experiment, 5 mL of blood was collected from each group of cats via the cephalic vein in the forearm on an empty stomach. 1 mL of the blood was placed in a heparin sodium tube to prepare anticoagulated blood, and 4 mL of the blood was placed in a sterile test tube. The blood was centrifuged at 1500 r / min for 5 min. The separated serum was stored at 4℃ for testing.

[0046] 2) Oxidative stress-related indicators: The activity levels of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in serum, as well as the content of malondialdehyde (MDA), were measured using a kit. The specific detection steps were strictly performed in accordance with the kit instructions.

[0047] 3) Inflammatory factors and immune markers: The levels of inflammatory factors such as interleukin-8 (IL-8), interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), as well as immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin A (IgA) in serum were detected using an enzyme-linked immunosorbent assay (ELISA) kit. All detection procedures were strictly performed in accordance with the kit instructions.

[0048] Basic cat food

[0049] The cat food base used in the examples and comparative examples is the same, and by weight percentage, it includes: animal protein ingredients (chicken meal, fish meal, etc.): 40%; grain or tuber ingredients: 25%; fat ingredients (chicken oil, fish oil): 12%; dietary fiber ingredients: 5%; vitamin and mineral premix: 3%; except for the functional additives, the composition of other ingredients and the preparation process are the same.

[0050] Example 1

[0051] The following immune-functional components were added to the basic diet: yeast β-glucan: 400 mg / kg; lactoferrin: 120 mg / kg; total selenium content: 0.5 mg / kg, of which organic selenium accounted for 85%.

[0052] Example 2

[0053] The following were added to the basic diet: yeast β-glucan: 300 mg / kg; lactoferrin: 100 mg / kg; total selenium content: 0.4 mg / kg, of which 80% was organic selenium.

[0054] Example 3

[0055] The following ingredients were added to the basic diet: yeast β-glucan: 500 mg / kg; lactoferrin: 150 mg / kg; total selenium content: 0.5 mg / kg, of which 85% was organic selenium.

[0056] Comparative Example 1

[0057] The cat food described in Comparative Example 1 is only a basic food and does not contain yeast beta-glucan, lactoferrin, or plant-derived organic selenium.

[0058] Comparative Example 2

[0059] The following ingredients are added to the basic diet: yeast beta-glucan 400 mg / kg; lactoferrin 120 mg / kg; no plant-derived organic selenium is added.

[0060] Comparative Example 3

[0061] Based on the basic diet, only plant-derived organic selenium is added, bringing the total selenium content in the cat food to 0.4 mg / kg; organic selenium accounts for 85% of the total selenium content. No yeast beta-glucan or lactoferrin is added.

[0062] Comparative Example 4

[0063] In addition to the basic food, add: yeast beta-glucan 400 mg / kg; lactoferrin 120 mg / kg; and inorganic selenium to make the total selenium content in the cat food 0.4 mg / kg.

[0064] Feeding trials were conducted using the cat foods described in Comparative Example 1 and Example 1, respectively. The food intake and weight changes of the cats in each group were monitored on days 1, 10, 20, and 30 of the trials. The results are as follows: Figure 1 As shown in the figure. Overall, the feed intake rate of Example 1 group was slightly lower than that of Comparative Example 1 group, but both groups maintained normal feed intake levels throughout the experiment, with no obvious refusal to eat or adverse reactions. Analysis of the trend in feed intake showed that the feed intake of cats in each group peaked around day 10 of the experiment, then showed a slow decline and gradually stabilized. This phenomenon may be related to the cats' adaptation process to the new diet; feed intake briefly increases during the adaptation period, and then returns to a relatively stable level after the adaptation period ends. Regarding growth performance, the weight gain rate of cats in each group continued to increase with the extension of the experiment time. Specifically, the weight gain rate of Example 1 group was generally higher than that of Comparative Example 1 group throughout the entire experiment. By day 30 of the experiment, the average weight gain rate of Example 1 group reached 5.85 ± 0.76%, significantly higher than the 2.07 ± 0.55% of Comparative Example 1 group (p < 0.05). The above results indicate that, without affecting normal feeding behavior, appropriate supplementation of plant-derived organic selenium in cat food helps promote the growth performance of cats, further demonstrating the potential advantages of the cat food described in Example 1 in terms of nutritional regulation.

[0065] Oxidative stress is closely related to the body's immune function and is an important physiological indicator for evaluating the health-promoting effects of functional cat foods. Table 1 shows the effects of different formulations and comparative cat foods on oxidative stress-related indicators in the experimental cats. At the start of the experiment (day 0), the serum CAT, SOD, GSH-Px activities, and MDA levels in each group of experimental cats were at similar levels, with small differences between groups, indicating good comparability of the baseline oxidative stress levels of the animals. After 30 consecutive days of feeding intervention, the indicators showed significant differentiation between the different formulations and the comparative, reflecting the different effects of different formulation combinations on the body's antioxidant status.

[0066] Regarding the antioxidant enzyme system (CAT, SOD, and GSH-Px), all groups in Examples 1–3 showed significantly higher enzyme activity levels than the comparative groups on day 30. Specifically, the CAT activity in the Example groups increased to 54.45–55.02 U / mL, SOD to 38.54–40.31 U / mL, and GSH-Px to 39.52–40.51 U / mL, all representing increases of approximately 40%–80% compared to day 0. In contrast, Comparative Example 1 (basal diet only) showed almost no significant improvement in the above enzyme activities after 30 days; Comparative Example 2 (lacking organic selenium) and Comparative Example 3 (organic selenium only) showed some improvement, but the overall levels were significantly lower than the Example groups; Comparative Example 4 (inorganic selenium added) showed a moderate improvement, but still less than the Example groups. These results indicate that the synergistic combination of yeast β-glucan, lactoferrin, and a high proportion of organic selenium can more effectively activate the body's endogenous antioxidant enzyme system.

[0067] Regarding lipid peroxidation (MDA) levels, the example groups also showed a more significant improvement. On day 30, the MDA levels in Examples 1–3 decreased significantly to 9.01–9.53 mmol / L, a reduction of approximately 44%–47% from the initial levels, significantly lower than the comparative groups. The MDA level in Comparative Example 1 remained almost unchanged, while Comparative Examples 2 and 4 showed only moderate decreases. Although Comparative Example 3 showed improvement compared to Comparative Example 1, it was still significantly higher than the example groups. As MDA is the end product of lipid peroxidation, the significant reduction indicates that the formulations in the examples can effectively alleviate oxidative damage and improve the overall oxidative stress state of the body.

[0068] Comprehensive analysis shows that the sample from the example studies was significantly superior to the comparative samples in increasing the activity of antioxidant enzymes such as CAT, SOD, and GSH-Px while reducing MDA content. In particular, the simultaneous addition of yeast β-glucan, lactoferrin, and a high proportion of plant-derived organic selenium exhibited a significant synergistic effect; while the antioxidant improvement effects of adding only one ingredient or replacing organic selenium with inorganic selenium were limited to varying degrees.

[0069] Table 1. Effects of the cat food in the examples and comparative cases on oxidative stress-related indicators in cats.

[0070]

[0071] Inflammatory factor levels are important indicators reflecting the body's immune homeostasis and the degree of inflammatory response. Based on the changes in serum pro-inflammatory factor indicators in Table 2, the differences between Examples 1–3 and the comparative samples after 30 days of feeding were significant. At the start of the experiment (day 0), the serum levels of IL-8, IL-1β, IL-6, and TNF-α in each group of cats were similar, indicating that the initial inflammatory state of the animals in each group was basically the same.

[0072] After 30 days of feeding, the levels of pro-inflammatory factors in groups 1–3 generally showed a decreasing trend. Specifically, IL-8 decreased from 10.9–11.5 pg / mL to 9.8–11.0 pg / mL; IL-1β decreased to 9.3–9.5 pg / mL; IL-6 decreased slightly or remained stable at 24.3–26.3 pg / mL; and TNF-α decreased most significantly, to 7.1–7.9 pg / mL. In contrast, the changes in inflammatory factors in groups 1–4 were not significant, especially in groups 1 and 2, where the levels of IL-8, IL-1β, and IL-6 remained basically unchanged or increased slightly, while TNF-α decreased only slightly; in groups 3 and 4, TNF-α decreased, but the overall level was still higher than that in the example groups.

[0073] These results indicate that the cat food in the examples has a significant advantage in reducing serum pro-inflammatory factor levels and inhibiting chronic low-grade inflammation, with a particularly significant decrease in TNF-α, suggesting its outstanding effect in regulating the body's inflammatory response. In contrast, the comparative formulations that added a single component or used inorganic selenium instead of organic selenium showed significantly less anti-inflammatory effect than the synergistic effect of the multi-component combination in the examples.

[0074] Table 2. Effects of the cat food on feline inflammatory markers in the examples and comparative cases.

[0075]

[0076] Immunoglobulin levels are important parameters reflecting the body's humoral immune function. As shown in Table 3, on day 0 of the experiment, the serum levels of immunoglobulin G (IgG), immunoglobulin A (IgA), and immunoglobulin M (IgM) in the experimental cats of each group were within similar ranges, with small differences between groups. This indicates that the initial immune status of the animals in each group was basically consistent, making them highly comparable.

[0077] After 30 consecutive days of feeding intervention, serum IgG levels in Examples 1–3 significantly increased, reaching 3.39, 3.50, and 3.43 mg / mL, respectively, more than doubling from the initial levels and significantly higher than the 1.63 mg / mL in Comparative Example 1. In contrast, although Comparative Examples 2–4 showed some improvement compared to Comparative Example 1, their IgG levels were still significantly lower than those in the Example groups, indicating that simply adding yeast β-glucan and lactoferrin, adding plant-derived organic selenium alone, or replacing organic selenium with inorganic selenium, are insufficient to achieve the immune-enhancing effect produced by the synergistic effect of multiple components.

[0078] Regarding IgA levels, the example groups also showed a more significant improvement. On day 30, the IgA levels in Examples 1–3 increased to 0.26–0.29 mg / mL, an increase of approximately 1.2–1.5 times compared to day 0, while Comparative Example 1 showed almost no change, remaining at around 0.10 mg / mL. Although IgA levels in Comparative Examples 2–4 increased, the increase was significantly lower than that in the example groups, suggesting that the example formulations have a more significant advantage in enhancing mucosal immune function.

[0079] Regarding IgM levels, groups 1–3 achieved levels of 0.49–0.54 mg / mL on day 30, significantly higher than the 0.29 mg / mL in Comparative Example 1. Comparative Examples 2–4 showed IgM levels between 0.34–0.41 mg / mL, which, while better than the basal diet group, were still lower than the Example groups. As an important indicator of the primary immune response, the significant increase in IgM levels indicates that the Example cat diets can more effectively activate the body's humoral immune response.

[0080] In summary, the cat foods described in Examples 1–3 were significantly superior to the comparative samples in increasing the levels of key immunoglobulins such as IgG, IgA, and IgM. The results indicate that the synergistic addition of yeast β-glucan, lactoferrin, and a high proportion of plant-derived organic selenium can significantly enhance the immune function of cats without inducing abnormal inflammatory responses.

[0081] Table 3. Effects of the cat food on feline immune indicators in the examples and comparative cases.

[0082]

[0083] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A cat food with immune-modulating function, characterized in that, This product adds immune-functional components to a basic cat food diet. These components include yeast beta-glucan, lactoferrin, and plant-derived organic selenium. The addition amount of yeast β-glucan is 300–500 mg / kg; The amount of lactoferrin added is 100–150 mg / kg; The total selenium content in cat food is 0.4–0.5 mg / kg, and organic selenium accounts for 80–90% of the total selenium content.

2. The cat food according to claim 1, characterized in that, The yeast β-glucan is derived from the cell wall of Saccharomyces cerevisiae or Kluyveromyces martensii, and its structural feature is a high molecular weight polysaccharide composed of a β-1,3-glucan backbone and β-1,6-glucan side chains.

3. The cat food according to claim 1, characterized in that, The lactoferrin is food-grade or feed-grade lactoferrin.

4. The cat food according to claim 1, characterized in that, The plant-derived organic selenium is selected from one or more of the following: selenium-enriched plant protein, selenium-enriched grain extract, and selenium-enriched vegetable extract.

5. The cat food according to claim 1, characterized in that, In the plant-derived organic selenium, selenium mainly exists in the form of selenomethionine, selenocysteine, and methylselenocysteine ​​bound to proteins or polypeptides.

6. The cat food according to claim 1, characterized in that, The cat food base includes animal protein ingredients, carbohydrate ingredients, fat ingredients, dietary fiber, and vitamin and mineral premixes.

7. The cat food according to claim 1, characterized in that, The yeast beta-glucan, lactoferrin, and plant-derived organic selenium are added to the cat food through a mixed or stepwise addition method.

8. The cat food according to claim 1, characterized in that, The cat food is extruded dry food, semi-wet food, or freeze-dried compound cat food.

9. The use of the cat food according to any one of claims 1–9 in improving the immune activity of cats, enhancing their stress resistance and maintaining their health.

Images