Iron absorption promoting probiotic compound powder and preparation method thereof

Abstract

This invention discloses a probiotic compound powder that promotes iron absorption and its preparation method. The compound powder consists of germinated grains, a bacterial / algal substrate, and *Lactobacillus plantarum* microcapsules. The fermentation substrate uses a composite substrate of germinated brown rice, germinated chickpeas, and fungi / spirulina fermented with *Bacillus subtilis*. The microcapsules are a blend of resistant starch, sodium alginate, fructooligosaccharides, tyrosine, ferrous gluconate, and vitamin C, with *Lactobacillus plantarum* BRX-1 as the core material. Microcapsule encapsulation technology enables the delivery and functional induction of probiotics. This invention significantly improves iron absorption through a dual-strain synergistic system. It also possesses multiple benefits, including regulating intestinal flora, improving latent iron deficiency, and enhancing immunity. It is suitable for people on diets, long-term vegetarian diets, and intermittent fasting, and has broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of functional meal replacement food technology, specifically to a probiotic compound powder that promotes iron absorption and its preparation method. Background Technology

[0002] Iron is an essential trace element for the human body, a crucial component of hemoglobin, myoglobin, and various enzyme systems, playing a vital role in oxygen transport, energy metabolism, and immune function. Iron deficiency leads to iron-deficiency anemia, manifesting as fatigue, weakness, and weakened immunity, seriously impacting human health. In recent years, with increased health awareness, dieting for weight loss, intermittent fasting, and long-term vegetarianism have become mainstream weight management and health maintenance methods. However, these dietary patterns generally suffer from iron nutrient metabolism deficiencies.

[0003] The overall food intake is drastically reduced under a diet-based weight loss model, resulting in a severe deficiency of basal iron intake from natural diets, which cannot meet the body's daily iron metabolism needs. Women and children are high-risk groups. More seriously, vegetarian diets are rich in anti-nutritional factors such as phytates, which strongly chelate iron ions in the intestines and block intestinal absorption pathways, causing iron absorption disorders such as difficulty in absorbing iron and ineffective iron supplementation.

[0004] Existing technologies for improving iron absorption mainly include direct iron supplements, iron-fortified foods, and naturally rich iron foods. However, these methods have significant drawbacks: direct iron supplements can easily cause gastrointestinal irritation, constipation, and other side effects; the bioavailability of iron ions in iron-fortified foods is low, and they easily combine with phytic acid to form insoluble complexes; naturally rich iron foods have limited iron content, making it difficult to meet the body's needs.

[0005] Probiotic technology offers a new approach to improving iron absorption. Studies have found that lactic acid bacteria can produce p-hydroxyphenyllactic acid (HPLA), a molecule capable of reducing Fe(III) to Fe(II), which can enter the DMT1 channel of intestinal cells and promote Fe(II) absorption. HPLA can mimic the function of DcytB ferric reductase protein, promoting iron absorption across the intestinal cell membrane. However, directly adding lactic acid bacteria presents challenges such as low viable colonization rates and unstable functional performance.

[0006] Microencapsulation technology is an effective means of improving the activity of probiotics. By encapsulating probiotics in protective wall materials, the acid resistance, bile salt resistance, and storage stability of the bacteria can be improved. Current microencapsulation technologies mainly focus on bacterial protection, but lack the co-delivery of functional precursors, making it difficult to achieve targeted induction and sustained exertion of probiotic functions.

[0007] Therefore, developing a probiotic compound powder that can simultaneously address iron absorption barriers, maintain probiotic activity, and induce targeted function is of significant scientific importance and application value. Summary of the Invention

[0008] Technical problems to be solved: Existing meal replacement products have low iron absorption rates, difficulty in maintaining probiotic activity, and unstable function. This invention provides a probiotic compound powder and its preparation method that can effectively promote iron absorption and maintain probiotic activity through raw material improvement, fermentation, and microencapsulation technology.

[0009] Technical solution: A method for preparing a probiotic compound powder that promotes iron absorption, comprising the following steps: S1. The fermentation raw materials are dried, pulverized and sieved at low temperature. The mixed powder is stirred with water to make a slurry. The slurry is sterilized at high temperature and then cooled. The pH is adjusted and Bacillus subtilis suspension is inoculated. Fermentation is carried out at constant temperature and stirred to obtain fermentation slurry. It is then sterilized at high temperature. S2. Resistant starch, sodium alginate, and fructooligosaccharides are mixed, water is added and stirred until swollen, cooled, and then a suspension of Lactobacillus plantarum is added and stirred at low speed to obtain a microcapsule solution. S3.L-tyrosine, ferrous gluconate, and vitamin C are mixed with warm water, stirred at a constant temperature, and the pH is adjusted to obtain a mixture. The mixture is then slowly added dropwise to the microcapsule solution, sheared and emulsified, and freeze-dried to obtain microcapsule powder. S4. After sieving, the fermented slurry is mixed with microcapsule powder using a mixer and then spray-dried at low temperature to obtain probiotic compound powder. Further, the fermentation raw materials in step S1 include, by weight, the following: 22-25 parts sprouted brown rice, 18-20 parts sprouted chickpeas, 15-20 parts sprouted quinoa, 4-7 parts shiitake mushrooms, 1-2 parts cordyceps militaris, 5-6 parts spirulina, 3-5 parts almonds, and 3-5 parts pine nuts.

[0010] Furthermore, in step S1, the mass ratio of the mixed powder to water is 6:(9-14); the stirring speed is 500-800 rpm; the instantaneous sterilization temperature is 121℃ and the time is 15-20s; the temperature is cooled to 32-37℃; the pH is adjusted to 6.0-6.5; the constant temperature stirring fermentation temperature is 32-37℃ and the time is 18-24h, with a stirring speed of 120-150 rpm.

[0011] Furthermore, in step S1, the Bacillus subtilis LX-W3 is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 27046, deposited on April 10, 2023, at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing; the concentration of the Bacillus subtilis suspension is 1×10⁻⁶. 8 CFU / g, the amount of Bacillus subtilis suspension inoculated is 3-4 wt.% of the slurry.

[0012] Furthermore, in step S2, the mass ratio of resistant starch, sodium alginate, fructooligosaccharide, and water is (3-4):(2-3):(1-2):(44-66); the stirring and swelling temperature is 50-60℃, the stirring speed is 500-800rpm, and the time is 40-60min; the cooling temperature is 30-35℃; the low-speed stirring speed is 80-100rpm, and the time is 15-30min.

[0013] Furthermore, in step S2, the *Lactobacillus plantarum* BRX-1 is deposited at the China General Microbiological Culture Collection Center (CGMCC), with accession number CGMCC No. 38511, deposit date of April 29, 2026, and address at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing; the concentration of the *Lactobacillus plantarum* suspension is 1×10⁻⁶. 9 -1×10 11 CFU / g; the amount of Lactobacillus plantarum suspension added is 30-50 wt.%.

[0014] Furthermore, in step S3, the mass ratio of L-tyrosine, ferrous gluconate, vitamin C, and warm water is (3-5):(2-3):(1-2):(14-20); the temperature of the warm water is 35-45℃; the constant temperature stirring temperature is 35-45℃, the rotation speed is 300-500 rpm, and the time is 25-40 min; the pH is adjusted to 5.5-6.0; the mass ratio of the mixture to the microcapsule liquid is 1:(9-10); the rotation speed of the shear emulsification is 3000-5000 rpm, and the time is 10-15 min.

[0015] Furthermore, in step S4, the mass ratio of microcapsule powder to fermentation slurry is 1:(100-110); the speed of the mixer is 300-500 rpm, and the time is 30-40 min.

[0016] The present invention also provides a probiotic compound powder that promotes iron absorption, prepared by the above-described preparation method. Beneficial effects

[0017] 1. The highly active phytase produced by Bacillus subtilis fermentation metabolism can degrade anti-nutritional factors such as phytic acid in the raw materials, eliminating the inhibitory effect of iron ions from the source; the organic acids produced by fermentation increase the solubility of iron ions, avoid the precipitation and inactivation of iron ions, and lay the foundation for iron absorption.

[0018] 2. The microcapsules can carry Lactobacillus plantarum BRX-1 into the intestine, first releasing L-tyrosine to provide HPLA synthesis precursors for the released Lactobacillus plantarum BRX-1. The presence of iron ions and tyrosine induce the strain to secrete p-hydroxyphenyllactic acid (HPLA), which efficiently reduces ferric iron to highly bioactive and directly absorbable ferrous iron, completing the conversion of iron ions into their active form and activating intestinal transport channels. This significantly improves the efficiency of iron ion transport in intestinal cell membranes and reduces the loss of iron ions in the intestine.

[0019] 3. This invention optimizes the raw materials in the compound powder formula, using germinated grains with low phytic acid content, while releasing glutamic acid and γ-aminobutyric acid (GABA) to reduce the digestive burden on the intestines; it also combines mushrooms and algae to replace traditional refined carbohydrates, which are naturally rich in plant organic iron, β-glucan and high-quality dietary fiber. Organic iron is milder and more easily tolerated than inorganic iron, which improves the basic iron intake level while ensuring the satiety and intestinal conditioning properties of the meal replacement.

[0020] 4. This invention utilizes Bacillus subtilis as a pre-fermentation functional bacterium and employs microcapsule encapsulation to protect the sensitive core functional strain Lactobacillus plantarum BRX-1, precisely avoiding the problem of BRX-1 inactivation and failure during processing, thus achieving the dual functioning of the two bacteria and ensuring full functional preservation throughout the process.

[0021] 5. The microcapsule wall material system has extremely high stability. It uses modified resistant starch, sodium alginate and oligofructose to form a dense and stable colloidal coating structure, which avoids bacterial inactivation and greatly improves the stability of probiotics at room temperature and the intestinal colonization rate.

[0022] 6. The microcapsules employ a composite structure of precursors loaded with wall material and auxiliary iron, which differs from ordinary single-encapsulated microcapsules. It has three core advantages: high stability, long-lasting sustained release, and functional induction. The microcapsule core material is highly pure and encapsulates BRX-1 live bacteria. The wall material and gaps are uniformly loaded with functional matrices such as L-tyrosine, ferrous gluconate, and vitamin C, which not only ensures the stability of the bacterial structure but also achieves long-term retention of functional precursors. After entering the intestine, the microcapsules disintegrate at specific sites, simultaneously releasing live bacteria, amino acids, and organic iron sources. This solves the problem of free tyrosine being easily decomposed and unable to continuously induce live bacteria production, ensuring that the strain can stably receive metabolic signals and continuously synthesize HPLA active substances after colonization.

[0023] 7. This product boasts a strong multi-functionality. In addition to enhancing iron absorption and improving latent iron deficiency and blood deficiency, it also regulates gut microbiota, repairs the intestinal barrier, and enhances metabolism. It is low in calories and low in burden, making it suitable for people who diet to lose weight, are long-term vegetarians, or engage in intermittent fasting. It has a wide range of applications and strong product compatibility, and can be widely used in multiple fields such as functional foods for weight management, dietary supplements for gut health, nutritional meal replacements for vegetarians, and iron supplementation products for sub-health conditions. It has extremely strong market competitiveness and practicality. Attached Figure Description

[0024] Figure 1 The graph shows the results of iron content in the liver and spleen of mice in Example 1 and the comparative experiment. Detailed Implementation

[0025] The present invention will be further described below with reference to embodiments. These embodiments are illustrative of the present invention, but the present invention is not limited to these embodiments: Example 1

[0026] A method for preparing a probiotic complex powder that promotes iron absorption includes the following steps: S1. Weigh out 23 parts by weight of sprouted brown rice, 19 parts by weight of sprouted chickpeas, 18 parts by weight of sprouted quinoa, 5 parts by weight of shiitake mushrooms, 1 part by weight of cordyceps militaris, 5.5 parts by weight of spirulina, 4 parts by weight of almonds, and 4 parts by weight of pine nuts. Dry all raw materials at low temperature, mix them, grind and sieve to obtain a mixed powder. Add water to the mixed powder at a mass ratio of 1:2, stir at 700 rpm to make a slurry, sterilize the slurry at 121℃ for 18 seconds, cool it to 35℃, adjust the pH of the slurry to 6.2, and inoculate it with 3.5 wt.% of Bacillus subtilis LX-W3 suspension, with a bacterial suspension concentration of 1×10⁻⁶. 8 CFU / g, stirring speed 120rpm, fermentation at 35℃ for 24h to obtain fermented slurry, instantaneous sterilization at 121℃ for 18s; S2. Weigh out the raw materials according to the mass ratio of resistant starch, sodium alginate, fructooligosaccharides, and water 3:2:1:44. Mix them, add water, and stir at 650 rpm for 50 min at 55℃ to allow them to swell. Cool the mixture to 32℃, and add 40 wt.% of *Lactobacillus plantarum* BRX-1 suspension (1×10⁻⁶ BX1 suspension). 10 CFU / g, stirred continuously at 90 rpm for 22 min to obtain microcapsule solution; S3.L-tyrosine, ferrous gluconate, vitamin C, and 40℃ warm water were weighed and mixed in a mass ratio of 3:2:1:14. The mixture was stirred at 400 rpm for 30 min at 40℃. The pH was adjusted to 5.5 to obtain a mixed solution. The mass ratio of the mixed solution to the microcapsule solution was 1:9. The composite mixed solution was slowly added dropwise to the microcapsule solution. The mixture was sheared and emulsified at 4000 rpm for 10 min. After freeze-drying, the mixture was pulverized and sieved to obtain composite microcapsule powder. S4. The fermentation slurry is sieved and then mixed in a sterile mixer at a mass ratio of 1:100 between the microcapsule powder and the fermentation slurry. The mixture is then mixed at 400 rpm for 35 minutes and spray-dried at low temperature to obtain the probiotic compound powder. Example 2

[0027] A method for preparing a probiotic complex powder that promotes iron absorption includes the following steps: S1. Weigh out 23 parts by weight of sprouted brown rice, 19 parts by weight of sprouted chickpeas, 18 parts by weight of sprouted quinoa, 5 parts by weight of shiitake mushrooms, 1 part by weight of cordyceps militaris, 5.5 parts by weight of spirulina, 4 parts by weight of almonds, and 4 parts by weight of pine nuts. Dry all raw materials at low temperature, mix them, grind and sieve to obtain a mixed powder. Add water to the mixed powder at a mass ratio of 3:7, stir at 700 rpm to make a slurry, sterilize the slurry at 121℃ for 18 seconds, cool it to 35℃, adjust the pH of the slurry to 6.2, and inoculate it with 3.5 wt.% of Bacillus subtilis LX-W3 suspension, with a bacterial suspension concentration of 1×10⁻⁶. 8 CFU / g, stirring speed 120rpm, fermentation at 35℃ for 24h to obtain fermented slurry, instantaneous sterilization at 121℃ for 18s; S2. Weigh out the raw materials according to the mass ratio of resistant starch, sodium alginate, fructooligosaccharides, and water 3:2:1:44. Mix them, add water, and stir at 650 rpm for 50 min at 55℃ to allow them to swell. Cool the mixture to 32℃, and add 40 wt.% of *Lactobacillus plantarum* BRX-1 suspension (1×10⁻⁶ BX1 suspension). 10 CFU / g, stirred continuously at 90 rpm for 22 min to obtain microcapsule solution; S3.L-tyrosine, ferrous gluconate, vitamin C, and 40℃ warm water were weighed and mixed in a mass ratio of 3:2:1:14. The mixture was stirred at 400 rpm for 30 min at 40℃. The pH was adjusted to 5.5 to obtain a mixed solution. The mass ratio of the mixed solution to the microcapsule solution was 1:9. The composite mixed solution was slowly added dropwise to the microcapsule solution. The mixture was sheared and emulsified at 4000 rpm for 10 min. After freeze-drying, the mixture was pulverized and sieved to obtain composite microcapsule powder. S4. The fermentation slurry is sieved and then mixed in a sterile mixer at a mass ratio of 1:100 between the microcapsule powder and the fermentation slurry. The mixture is then mixed at 400 rpm for 35 minutes and spray-dried at low temperature to obtain the probiotic compound powder. Example 3

[0028] A method for preparing a probiotic complex powder that promotes iron absorption includes the following steps: S1. Weigh out 23 parts by weight of sprouted brown rice, 19 parts by weight of sprouted chickpeas, 18 parts by weight of sprouted quinoa, 5 parts by weight of shiitake mushrooms, 1 part by weight of cordyceps militaris, 5.5 parts by weight of spirulina, 4 parts by weight of almonds, and 4 parts by weight of pine nuts. Dry all raw materials at low temperature, mix them, grind and sieve to obtain a mixed powder. Add water to the mixed powder at a mass ratio of 1:2, stir at 700 rpm to make a slurry, sterilize the slurry at 121℃ for 18 seconds, cool it to 35℃, adjust the pH of the slurry to 6.2, and inoculate it with 3.5 wt.% of Bacillus subtilis LX-W3 suspension, with a bacterial suspension concentration of 1×10⁻⁶. 8 CFU / g, stirring speed 120rpm, fermentation at 35℃ for 18h to obtain fermented slurry, instantaneous sterilization at 121℃ for 18s; S2. Weigh out the raw materials according to the mass ratio of resistant starch, sodium alginate, fructooligosaccharides, and water 3:2:1:44. Mix them, add water, and stir at 55°C and 650 rpm for 50 min to swell. Cool the mixture to 32°C, and add 40 wt.% of *Lactobacillus plantarum* BRX-1 suspension (1×10⁻⁶ BX1 concentration) of the total mass of the mixture. 10 CFU / g, stirred continuously at 90 rpm for 22 min to obtain microcapsule solution; S3.L-tyrosine, ferrous gluconate, vitamin C, and 40℃ warm water were weighed and mixed in a mass ratio of 3:2:1:14. The mixture was stirred at 400 rpm for 30 min at 40℃. The pH was adjusted to 5.5 to obtain a mixed solution. The mass ratio of the mixed solution to the microcapsule solution was 1:9. The composite mixed solution was slowly added dropwise to the microcapsule solution. The mixture was sheared and emulsified at 4000 rpm for 10 min. After freeze-drying, the mixture was pulverized and sieved to obtain composite microcapsule powder. S4. The fermentation slurry is sieved and then mixed in a sterile mixer at a mass ratio of 1:100 between the microcapsule powder and the fermentation slurry. The mixture is then mixed at 400 rpm for 35 minutes and spray-dried at low temperature to obtain the probiotic compound powder. Example 4

[0029] A method for preparing a probiotic complex powder that promotes iron absorption includes the following steps: S1. Weigh out 23 parts by weight of sprouted brown rice, 19 parts by weight of sprouted chickpeas, 18 parts by weight of sprouted quinoa, 5 parts by weight of shiitake mushrooms, 1 part by weight of cordyceps militaris, 5.5 parts by weight of spirulina, 4 parts by weight of almonds, and 4 parts by weight of pine nuts. Dry all raw materials at low temperature, mix them, grind and sieve to obtain a mixed powder. Add water to the mixed powder at a mass ratio of 1:2, stir at 700 rpm to make a slurry, sterilize the slurry at 121℃ for 18 seconds, cool it to 35℃, adjust the pH of the slurry to 6.2, and inoculate it with 3.5 wt.% of Bacillus subtilis LX-W3 suspension, with a bacterial suspension concentration of 1×10⁻⁶. 8 CFU / g, stirring speed 120rpm, fermentation at 35℃ for 24h to obtain fermented slurry, instantaneous sterilization at 121℃ for 18s; S2. Weigh out the raw materials according to the mass ratio of resistant starch, sodium alginate, fructooligosaccharides, and water 3:3:1:53, mix them, add water, and stir at 55℃ and 650rpm for 50min to swell. Cool the mixture to 32℃, and add 40wt.% of *Lactobacillus plantarum* BRX-1 suspension (1×10⁻⁶) of the total mass of the mixture. 10 CFU / g, stirred continuously at 90 rpm for 22 min to obtain microcapsule solution; S3.L-tyrosine, ferrous gluconate, vitamin C, and 40℃ warm water were weighed and mixed in a mass ratio of 3:2:1:14. The mixture was stirred at 400 rpm for 30 min at 40℃. The pH was adjusted to 5.5 to obtain a mixed solution. The mass ratio of the mixed solution to the microcapsule solution was 1:9. The composite mixed solution was slowly added dropwise to the microcapsule solution. The mixture was sheared and emulsified at 4000 rpm for 10 min. After freeze-drying, the mixture was pulverized and sieved to obtain composite microcapsule powder. S4. The fermentation slurry is sieved and then mixed in a sterile mixer at a mass ratio of 1:100 between the microcapsule powder and the fermentation slurry. The mixture is then mixed at 400 rpm for 35 minutes and spray-dried at low temperature to obtain the probiotic compound powder. Example 5

[0030] A method for preparing a probiotic complex powder that promotes iron absorption includes the following steps: S1. Weigh out 23 parts by weight of sprouted brown rice, 19 parts by weight of sprouted chickpeas, 18 parts by weight of sprouted quinoa, 5 parts by weight of shiitake mushrooms, 1 part by weight of cordyceps militaris, 5.5 parts by weight of spirulina, 4 parts by weight of almonds, and 4 parts by weight of pine nuts. Dry all raw materials at low temperature, mix them, grind and sieve to obtain a mixed powder. Add water to the mixed powder at a mass ratio of 1:2, stir at 700 rpm to make a slurry, sterilize the slurry at 121℃ for 18 seconds, cool it to 35℃, adjust the pH of the slurry to 6.2, and inoculate it with 3.5 wt.% of Bacillus subtilis LX-W3 suspension, with a bacterial suspension concentration of 1×10⁻⁶. 8 CFU / g, stirring speed 120rpm, fermentation at 35℃ for 24h to obtain fermented slurry, instantaneous sterilization at 121℃ for 18s; S2. Weigh out the raw materials according to the mass ratio of resistant starch, sodium alginate, fructooligosaccharides, and water 3:2:1:44. Mix them, add water, and stir at 650 rpm for 50 min at 55℃ to allow them to swell. Cool the mixture to 32℃, and add 40 wt.% of *Lactobacillus plantarum* BRX-1 suspension (1×10⁻⁶ BX1 suspension). 10 CFU / g, stirred continuously at 90 rpm for 22 min to obtain microcapsule solution; S3.L-tyrosine, ferrous gluconate, vitamin C, and 40℃ warm water were weighed and mixed in a mass ratio of 3:3:1:18. The mixture was stirred at 400 rpm for 30 min at 40℃. The pH was adjusted to 5.5 to obtain a mixed solution. The mass ratio of the mixed solution to the microcapsule solution was 1:9. The composite mixed solution was slowly added dropwise to the microcapsule solution. The mixture was sheared and emulsified at 4000 rpm for 10 min. After freeze-drying, the mixture was pulverized and sieved to obtain composite microcapsule powder. S4. The fermentation slurry is sieved and then mixed in a sterile mixer at a mass ratio of 1:100 between the microcapsule powder and the fermentation slurry. The mixture is then mixed at 400 rpm for 35 minutes and spray-dried at low temperature to obtain the probiotic compound powder. Example 6

[0031] A method for preparing a probiotic complex powder that promotes iron absorption includes the following steps: S1. Weigh out 23 parts by weight of sprouted brown rice, 19 parts by weight of sprouted chickpeas, 18 parts by weight of sprouted quinoa, 5 parts by weight of shiitake mushrooms, 1 part by weight of cordyceps militaris, 5.5 parts by weight of spirulina, 4 parts by weight of almonds, and 4 parts by weight of pine nuts. Dry all raw materials at low temperature, mix them, grind and sieve to obtain a mixed powder. Add water to the mixed powder at a mass ratio of 1:2, stir at 700 rpm to make a slurry, sterilize the slurry at 121℃ for 18 seconds, cool it to 35℃, adjust the pH of the slurry to 6.2, and inoculate it with 3.5 wt.% of Bacillus subtilis LX-W3 suspension, with a bacterial suspension concentration of 1×10⁻⁶. 8 CFU / g, stirring speed 120rpm, fermentation at 35℃ for 24h to obtain fermented slurry, instantaneous sterilization at 121℃ for 18s; S2. Weigh out the raw materials according to the mass ratio of resistant starch, sodium alginate, fructooligosaccharides, and water 3:2:1:44. Mix them, add water, and stir at 55°C and 650 rpm for 50 min to swell. Cool the mixture to 32°C, and add 40 wt.% of *Lactobacillus plantarum* BRX-1 suspension (1×10⁻⁶ BX1 concentration) of the total mass of the mixture. 10 CFU / g, stirred continuously at 90 rpm for 22 min to obtain microcapsule solution; S3.L-tyrosine, ferrous gluconate, vitamin C, and 40℃ warm water were weighed and mixed in a mass ratio of 3:2:1:14. The mixture was stirred at 400 rpm for 30 min at 40℃. The pH was adjusted to 5.5 to obtain a mixed solution. The mass ratio of the mixed solution to the microcapsule solution was 1:10. The composite mixed solution was slowly added dropwise to the microcapsule solution. The mixture was sheared and emulsified at 4000 rpm for 10 min. After freeze-drying, the mixture was pulverized and sieved to obtain composite microcapsule powder. S4. The fermentation slurry is sieved and then mixed in a sterile mixer at a mass ratio of 1:100 between the microcapsule powder and the fermentation slurry. The mixture is then mixed at 400 rpm for 35 minutes and spray-dried at low temperature to obtain the probiotic compound powder. Example 7

[0032] A method for preparing a probiotic complex powder that promotes iron absorption includes the following steps: S1. Weigh out 23 parts by weight of sprouted brown rice, 19 parts by weight of sprouted chickpeas, 18 parts by weight of sprouted quinoa, 5 parts by weight of shiitake mushrooms, 1 part by weight of cordyceps militaris, 5.5 parts by weight of spirulina, 4 parts by weight of almonds, and 4 parts by weight of pine nuts. Dry all raw materials at low temperature, mix them, grind and sieve to obtain a mixed powder. Add water to the mixed powder at a mass ratio of 1:2, stir at 700 rpm to make a slurry, sterilize the slurry at 121℃ for 18 seconds, cool it to 35℃, adjust the pH of the slurry to 6.2, and inoculate it with 3.5 wt.% of Bacillus subtilis LX-W3 suspension, with a bacterial suspension concentration of 1×10⁻⁶.8 CFU / g, stirring speed 120rpm, fermentation at 35℃ for 24h to obtain fermented slurry, instantaneous sterilization at 121℃ for 18s; S2. Weigh out the raw materials according to the mass ratio of resistant starch, sodium alginate, fructooligosaccharides, and water 3:2:1:44. Mix them, add water, and stir at 650 rpm for 50 min at 55℃ to allow them to swell. Cool the mixture to 32℃, and add 40 wt.% of *Lactobacillus plantarum* BRX-1 suspension (1×10⁻⁶ BX1 suspension). 10 CFU / g, stirred continuously at 90 rpm for 22 min to obtain microcapsule solution; S3.L-tyrosine, ferrous gluconate, vitamin C, and 40℃ warm water were weighed and mixed in a mass ratio of 3:2:1:14. The mixture was stirred at 400 rpm for 30 min at 40℃. The pH was adjusted to 5.5 to obtain a mixed solution. The mass ratio of the mixed solution to the microcapsule solution was 1:9. The composite mixed solution was slowly added dropwise to the microcapsule solution. The mixture was sheared and emulsified at 4000 rpm for 10 min. After freeze-drying, the mixture was pulverized and sieved to obtain composite microcapsule powder. S4. The fermentation slurry is sieved and then mixed in a sterile mixer at a mass ratio of 1:100 between the microcapsule powder and the fermentation slurry. The mixture is then mixed at 400 rpm for 35 minutes and spray-dried at low temperature to obtain the probiotic compound powder. Comparative Example 1

[0033] The difference between this comparative example and Example 1 is that Bacillus subtilis LX-W3 was not added for fermentation, while the other conditions and steps are the same. Comparative Example 2

[0034] The difference between this comparative example and Example 1 is that Lactobacillus plantarum BRX-1 was not added, while the other conditions and steps were the same. Comparative Example 3

[0035] The difference between this comparative example and Example 1 is that L-tyrosine is not added, while the other conditions and steps are the same. Comparative Example 4

[0036] The difference between this comparative example and Example 1 is that ferrous gluconate is not added, while the other conditions and steps are the same. Comparative Example 5

[0037] The difference between this comparative example and Example 1 is that resistant starch, sodium alginate, and fructooligosaccharides were not added to prepare the microcapsules. The Lactobacillus plantarum BRX-1 suspension was directly mixed with L-tyrosine, ferrous gluconate, vitamin C, and fermentation slurry. All other conditions and steps were the same. Comparative Example 6

[0038] The difference between this comparative example and Example 1 is that the raw materials are not sprouted, but ordinary brown rice, chickpeas, and quinoa are used, while the other conditions and steps are the same. Performance testing

[0039] Sensory evaluation Ten sensory evaluators conducted a blind taste test on the compound powder. Evaluation factors included color, texture, flavor, and reconstitution properties, with each evaluator scoring independently. A 10-point scale was used for scoring, with 9-10 points being excellent, 7-8 points being good, 5-6 points being average, and below 5 points being poor.

[0040] The sensory evaluation results are shown in Table 1. Fermentation process and raw materials are the main factors affecting sensory evaluation. All four indicators in Comparative Examples 1 and 6 fell below 7 points, with an overall rating of "average". This may be because when fermented with Bacillus subtilis, a large amount of phytic acid, macromolecular starch, and crude protein in the grains were not degraded, resulting in a coarse, sticky texture and a strong raw grain smell after reconstitution. Ordinary unsprouted raw materials themselves have a high phytic acid content, coarse and hard fibers, a dark yellow color, and are prone to clumping and separation when reconstituted.

[0041] Table 1 Sensory evaluation scores

[0042] Probiotic activity To simulate gastrointestinal fluid tolerance, artificial gastric fluid (pH 2.0) and artificial intestinal fluid (pH 6.8) were prepared. The composite powder suspension (1 mg / mL) was added to the artificial gastric fluid, and the survival rate was measured after incubation at 37°C for 1 h. Then, the gastric fluid-treated samples were transferred to the artificial intestinal fluid, and the survival rate was measured after incubation at 37°C for 2 h.

[0043] The results are shown in Table 2. The initial viable count, gastric juice tolerance, and intestinal juice tolerance of the embodiment were significantly better than all the comparative examples. Microencapsulation is the core key to improving the survival and gastrointestinal tolerance of probiotics. The ratio of fermentation raw materials and wall materials can slightly change the tolerance performance.

[0044] Table 2 Results of Probiotic Activity Assay

[0045] animal experiments Mice were housed in a standard environment for one week. Ten mice were randomly selected as the normal control group, and these mice were fed a standard diet until the end of the experiment. The remaining mice were fed an iron-deficient diet for eight weeks to establish an iron-deficiency anemia mouse model. After eight weeks, blood was collected via orbital vein puncture for routine blood tests. A hemoglobin level less than 100 g / L was considered iron-deficiency anemia. After the iron-deficiency model was established, mice were divided into nine groups of ten each: an anemia model group, a positive control group, Example 1 group, and six comparative groups. Mice in the normal and anemia model groups were given deionized water daily. The iron-deficiency anemia mice in each experimental group were administered the corresponding samples and FeSO4 via gavage, while the positive control group received only FeSO4. The weight of all mice was monitored weekly for three weeks.

[0046] After the procedure, all mice were fasted for 18 hours. The mice were anesthetized with isoflurane, and blood was collected for testing.

[0047] 0.1 g of liver or spleen was transferred to a mixed acid solution consisting of concentrated nitric acid and perchloric acid. The contents were heated to 85°C for 24 hours, then the temperature was adjusted to 110°C and heated for another 5 hours. Digestion was considered complete when the solution became colorless. After digestion, the solution was diluted, and the iron content in the digestive fluid was determined using inductively coupled plasma atomic emission spectrometry (ICP-AES).

[0048] The results are shown in Table 3. In the anemia model group, hemoglobin was 81.33±12.47 g / L and serum iron was only 18.94±0.65 μmol / L. Both indicators were significantly lower than those in the blank normal group, proving the successful establishment of the iron deficiency anemia mouse model, which can be used to evaluate the effects of samples on promoting iron absorption and improving anemia. In Example 1, hemoglobin was 146.89±3.67 g / L and serum iron was 41.62±1.19 μmol / L, significantly better than the positive control group, and serum iron levels were close to those of normal mice. In Comparative Example 1, the phytic acid used was not degraded by phytase, and phytic acid chelated intestinal iron ions, significantly reducing iron absorption rate; hemoglobin and serum iron were significantly lower than in Example 1. In Comparative Example 5, the probiotic activity was reduced, limiting iron absorption efficiency, and the indicators were low. In Comparative Example 3, the lack of tyrosine as a precursor significantly reduced the ability of *Lactobacillus plantarum* to synthesize iron-promoting substances.

[0049] Figure 1 The results of iron content measurements in the liver and spleen showed that the cumulative iron content in Example 1 was close to that of the normal group. While the comparative group showed some improvement compared to the model group, the effect was not as good as in Example 1. In Comparative Example 1, due to the presence of anti-absorption factors such as phytic acid (potentially unfermented), iron absorption was slightly lower than in the control group even with supplementation, indicating that consuming foods high in phytic acid can affect iron absorption.

[0050] Table 3 Blood test results from animal experiments

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the spirit and technical essence of the present invention. Therefore, any simple modifications, equivalent substitutions, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the technical solutions of the present invention, shall still fall within the scope of protection of the present invention.

Claims

1. A method for preparing a probiotic compound powder that promotes iron absorption, characterized in that, Includes the following steps: S1. The fermentation raw materials are dried, pulverized and sieved at low temperature. The mixed powder is stirred with water to make a slurry. The slurry is sterilized at high temperature and then cooled. The pH is adjusted and Bacillus subtilis suspension is inoculated. Fermentation is carried out at constant temperature and stirred to obtain fermentation slurry. It is then sterilized at high temperature. S2. Resistant starch, sodium alginate, and fructooligosaccharides are mixed, water is added and stirred until swollen, cooled, and then a suspension of Lactobacillus plantarum is added and stirred at low speed to obtain a microcapsule solution; S3.L-tyrosine, ferrous gluconate, and vitamin C are mixed with warm water, stirred at a constant temperature, and the pH is adjusted to obtain a mixture. The mixture is then slowly added dropwise to the microcapsule solution, sheared and emulsified, and freeze-dried to obtain microcapsule powder. S4. After the fermentation slurry is sieved, it is mixed with microcapsule powder in a mixer and then spray-dried at low temperature to obtain probiotic compound powder.

2. The method for preparing a probiotic compound powder that promotes iron absorption according to claim 1, characterized in that: The fermentation raw materials in step S1 include, by weight, 22-25 parts of sprouted brown rice, 18-20 parts of sprouted chickpeas, 15-20 parts of sprouted quinoa, 4-7 parts of shiitake mushrooms, 1-2 parts of cordyceps militaris, 5-6 parts of spirulina, 3-5 parts of almonds, and 3-5 parts of pine nuts.

3. The method for preparing a probiotic compound powder that promotes iron absorption according to claim 1, characterized in that: In step S1, the mass ratio of the mixed powder to water is 6:(9-14); the stirring speed is 500-800 rpm; the instantaneous sterilization temperature is 121℃ and the time is 15-20s; the temperature is cooled to 32-37℃; the pH is adjusted to 6.0-6.5; the constant temperature stirring fermentation temperature is 32-37℃ and the time is 18-24h, with a stirring speed of 120-150 rpm.

4. The method for preparing a probiotic compound powder that promotes iron absorption according to claim 1, characterized in that: In step S1, the Bacillus subtilis strain LX-W3 was deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 27046, deposited on April 10, 2023, at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing; the concentration of the Bacillus subtilis suspension was 1×10⁻⁶. 8 CFU / g, the amount of Bacillus subtilis suspension inoculated is 3-4 wt.% of the slurry.

5. The method for preparing a probiotic compound powder that promotes iron absorption according to claim 1, characterized in that: In step S2, the mass ratio of resistant starch, sodium alginate, fructooligosaccharide, and water is (3-4):(2-3):(1-2):(44-66); the stirring and swelling temperature is 50-60℃, the stirring speed is 500-800 rpm, and the time is 40-60 min; the cooling temperature is 30-35℃; the low-speed stirring speed is 80-100 rpm, and the time is 15-30 min.

6. The method for preparing a probiotic compound powder that promotes iron absorption according to claim 1, characterized in that: In step S2, the *Lactobacillus plantarum* BRX-1 is deposited at the China General Microbiological Culture Collection Center (CGMCC), accession number CGMCC No. 38511, deposited on April 29, 2026, at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing; the concentration of the *Lactobacillus plantarum* suspension is 1×10⁻⁶. 9 -1×10 11 CFU / g; the amount of Lactobacillus plantarum suspension added is 30-50 wt.%.

7. The method for preparing a probiotic compound powder that promotes iron absorption according to claim 1, characterized in that: In step S3, the mass ratio of L-tyrosine, ferrous gluconate, vitamin C, and warm water is (3-5):(2-3):(1-2):(14-20); the temperature of the warm water is 35-45℃; the constant temperature stirring temperature is 35-45℃, the speed is 300-500 rpm, and the time is 25-40 min; the pH is adjusted to 5.5-6.0; the mass ratio of the mixture to the microcapsule liquid is 1:(9-10); the speed of shear emulsification is 3000-5000 rpm, and the time is 10-15 min.

8. The method for preparing a probiotic compound powder that promotes iron absorption according to claim 1, characterized in that: In step S4, the mass ratio of microcapsule powder to fermentation slurry is 1:(100-110); the speed of the mixer is 300-500 rpm, and the time is 30-40 min.

9. A probiotic compound powder that promotes iron absorption, prepared by any one of the preparation methods according to claims 1-8.

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