A synbiotic composition and uses thereof

Abstract

This invention discloses a synbiotic composition and its application, relating to the field of functional food technology. The synbiotic composition disclosed in this invention includes probiotics and prebiotics; the probiotics are selected from at least one of *Lactobacillus acidophilus* NCFM and *Lactobacillus plantarum* 6595; the prebiotics are selected from at least one of stachyose, fructooligosaccharides, and yeast spore β-glucan. This invention studies the hypoglycemic and lipid-lowering abilities, gastrointestinal tolerance, Caco-2 cell adhesion ability, and inter-strain antagonism of the three bacterial powders through in vitro culture, determining that *Lactobacillus acidophilus* and *Lactobacillus plantarum* can synergistically enhance each other when combined. Simultaneously, the optimal prebiotic that promotes bacterial proliferation is screened for compounding, and the effects of different proportions of compounded prebiotics on the proliferation of mixed bacterial strains are measured. Combined with in vitro simulated colonic fermentation experiments, the optimal compounding ratio of prebiotics is determined, thus providing a theoretical basis for the development of optimal probiotic-prebiotic (synbiotic) formulations.

Description

Technical Field

[0001] This invention relates to the field of functional food technology, and in particular to a synbiotic composition and its application. Background Technology

[0002] Diabetes and cardiovascular disease are among the leading causes of death and disease worldwide. Although various medications are available to effectively control blood sugar and lipid levels, long-term use often results in side effects such as liver and kidney damage. Furthermore, patient adherence is poor, especially when faced with complex treatment regimens. Therefore, there is an urgent need for a safer alternative with fewer side effects that can effectively manage blood sugar and lipids in the long term.

[0003] Synbiotics are a combination of probiotics and prebiotics. Probiotics help regulate metabolic function by improving the balance of gut microbiota; while prebiotics can selectively promote the metabolism and proliferation of beneficial bacteria in the body, thus helping to improve health. Chinese Patent CN110150669A discloses a probiotic composition suitable for diabetic patients and its application. The composition includes *Lactobacillus plantarum* YMC1005 (trade number LP45), *Lactobacillus acidophilus* La28, *Bifidobacterium lactis* BAL531, and prebiotics. This probiotic composition can be used as a functional food for type 2 diabetic patients and can improve their blood sugar status. Chinese patent CN117243376A discloses a synbiotic microecological preparation with the function of improving metabolic syndrome and its application. The components include probiotics and prebiotics; the probiotics include *Bifidobacterium animalis* subsp. *lactospirum* WHH2276, *Lactobacillus fermentum* WHH3906, *Lactobacillus fermentum* 2644, and *Lactobacillus rhamnosus* 1155; the prebiotics include fructooligosaccharides and galactooligosaccharides. Current research mostly focuses on the effects of probiotics or prebiotics alone on metabolic health, but research on the effects of synbiotic combinations on lowering blood sugar and lipids is relatively limited, and factors such as the types and proportions of combinations are still under exploration. This provides a huge potential space for the development of novel synbiotic combinations, and by optimizing the combination, its metabolic regulatory effect can be further enhanced.

[0004] In view of this, in order to overcome the shortcomings of the prior art, the present invention provides a synbiotic composition and its application. Summary of the Invention

[0005] The purpose of this invention is to provide a synbiotic composition and its application, which greatly improves the in vitro hypoglycemic ability, in vitro cholesterol-lowering ability and intestinal flora proliferation ability of the synbiotic composition.

[0006] To achieve the above-mentioned objectives, the technical solution of this invention is as follows:

[0007] On the one hand, the present invention provides a synbiotic composition comprising probiotics and prebiotics;

[0008] The probiotics are selected from at least one of Lactobacillus acidophilus NCFM and Lactobacillus plantarum 6595;

[0009] The prebiotic is selected from at least one of stachyose, fructooligosaccharides, and yeast spore β-glucan.

[0010] Preferably, the probiotics are Lactobacillus acidophilus NCFM and Lactobacillus plantarum 6595.

[0011] More preferably, the mass ratio of Lactobacillus acidophilus NCFM to Lactobacillus plantarum 6595 is 1:0.1-1.

[0012] More preferably, the mass ratio of Lactobacillus acidophilus NCFM to Lactobacillus plantarum 6595 is 1:1.

[0013] Preferably, the prebiotic is stachyose, fructooligosaccharide, and yeast spore β-glucan.

[0014] More preferably, the mass ratio of stachyose, fructooligosaccharide and yeast spore β-glucan is 1-3:1-3:1-3.

[0015] More preferably, the mass ratio of stachyose, fructooligosaccharide and water-soluble β-glucan is 2-3:2-3:1.

[0016] More preferably, the mass ratio of stachyose, fructooligosaccharide and water-soluble β-glucan is 3:2:1.

[0017] Preferably, the mass ratio of probiotics to prebiotics is 1:0.1-1.

[0018] More preferably, the mass ratio of probiotics to prebiotics is 1:1.

[0019] In another aspect, the present invention provides the use of the above-mentioned synbiotic composition in the preparation of food, dietary supplements or pharmaceuticals.

[0020] Preferably, the food, dietary supplement, or medicine is used to treat one or more of the following diseases and conditions in mammals:

[0021] (1) Regulates gut microbiota;

[0022] (2) Improves abnormal blood sugar and blood lipid levels;

[0023] (3) Improve obesity, reduce body fat and / or reduce mesenteric fat;

[0024] (4) Improves type 2 diabetes;

[0025] (5) Improve insulin resistance.

[0026] The beneficial effects of this invention are as follows:

[0027] (1) The synbiotic provided by the present invention is a combination of multiple probiotics and multiple prebiotics, which can work synergistically in the complex intestinal environment and can better improve metabolic syndrome.

[0028] (2) This invention provides a synbiotic composition and its application. The hypoglycemic ability, lipid-lowering ability, gastrointestinal tolerance, Caco-2 cell adhesion ability, and inter-strain antagonism of three bacterial powders (Lactobacillus acidophilus, Lactobacillus plantarum and their mixture) were studied by in vitro culture. It was determined that Lactobacillus acidophilus and Lactobacillus plantarum can be synergistically enhanced when combined.

[0029] (3) This invention studies the effects of different types of prebiotics on the growth of three types of bacterial powders and determines that stachyose, fructooligosaccharides and yeast spore β-glucan are most beneficial to the growth of the three types of bacterial powders.

[0030] (4) This invention studies the effects of different compound ratios of prebiotics (stachyose, fructooligosaccharides, and yeast spore β-glucan) on the proliferation of mixed strains, and combined with colon fermentation experiments, determines that the optimal compound ratio of prebiotics is 3:2:1.

[0031] (5) The synbiotic composition provided by the present invention has a good ability to regulate intestinal flora. Attached Figure Description

[0032] Figure 1 This shows the growth of Lactobacillus plantarum in different types of prebiotics.

[0033] Figure 2 This shows the growth of mixed strains in different types of prebiotics.

[0034] Figure 3 This shows the growth of Lactobacillus acidophilus in different types of prebiotics.

[0035] Figure 4 The utilization of different prebiotics by the three strains is shown.

[0036] Figure 5 This shows the growth of mixed strains in prebiotics with different compound ratios.

[0037] Figure 6 The results of colonic fermentation experiments with different ratios of prebiotics are shown. LAC / UNI represents Lactobacillus regulation, BIF / UNI represents Bifidobacterium regulation, and AKK / UNI represents Akkermansia regulation. Different lowercase letters in the figure indicate significant differences.

[0038] Figure 7 The growth and acid production of Lactobacillus plantarum, Lactobacillus acidophilus, and mixed strains in prebiotics with optimal compound ratios were studied. Detailed Implementation

[0039] The following non-limiting embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way. The following description is merely an exemplary illustration of the scope of protection of the present invention, and those skilled in the art can make various changes and modifications to the invention based on the disclosed content, which should also fall within the scope of protection of the present invention.

[0040] The present invention will be further described below by way of specific embodiments. Unless otherwise specified, all chemical reagents used in the embodiments of the present invention were obtained through conventional commercial means. Unless otherwise specified, all contents mentioned below are mass contents. Unless otherwise specified, it is understood that the process was carried out at room temperature.

[0041] 1. Reagents

[0042] The Lactobacillus acidophilus NCFM lyophilized powder was purchased from Danisco (China) Co., Ltd.

[0043] The freeze-dried powder of Lactobacillus plantarum 6595 was purchased from Danisco (China) Co., Ltd.

[0044] The mixed strains (Lactobacillus acidophilus NCFM and Lactobacillus plantarum 6595) were mixed in a mass ratio (m / m) of 1:1.

[0045] 2. Preparation of reagents

[0046] (1) Cholesterol (0.1 mg / mL)-MRS medium: Weigh (m / m) bile salts, sucrose, cholesterol and fatty acid esters in a ratio of 2:1:1, add 1 part Tween-80 and 5 parts anhydrous ethanol and mix well. Sonicate in an 80°C water bath until completely dissolved, then add to MRS medium and mix well.

[0047] (2) Fermentation medium (1L): Sodium chloride 0.1g, dipotassium hydrogen phosphate 0.04g, potassium dihydrogen phosphate 0.04g, magnesium sulfate 0.01g, calcium chloride 0.01g, sodium bicarbonate 2g, peptone 2.5g, yeast extract 4g, glucose 0.4g, mucin 2g, bile salts III 0.5g, cysteine ​​salt 0.46g, Tween-80 2mL. Mix and adjust to pH 7.0 (1M HCl). Autoclave at 121℃ for 15min. Cool and set aside.

[0048] (3) Simulated gastric juice: Weigh 0.35g of pepsin (250U / mg) into 100mL of 0.2% sterile physiological saline, adjust the pH to 3.0 with 1M HCl, and filter to remove bacteria to obtain simulated gastric juice.

[0049] (4) Simulated intestinal fluid: Weigh 0.1g pancreatic enzyme (4U), 0.3g bile salt III and 1.1g NaHCO3, dissolve in 100mL 0.2% sterile physiological saline, adjust pH to 8.0, and filter through a sterile filter membrane.

[0050] 3. Activation of bacterial strains and sample preparation

[0051] Weigh 0.1 g of bacterial powder into 5 mL of MRS broth and incubate in a 37°C anaerobic incubator. Subculture every 12 hours (add 200 μL of the stock solution to fresh broth). Take the strain in the logarithmic growth phase, centrifuge at 8000 rpm for 1 min, discard the supernatant in a clean bench, and add a certain amount of sterile PBS to the bacterial sludge to adjust the bacterial suspension concentration to OD0.05. 600 =1, vortex oscillation to mix evenly, ready for use.

[0052] Example 1: Screening of strains

[0053] 1. Gastrointestinal tolerance analysis

[0054] 1.1 Analytical Methods

[0055] 0.5 mL of the test bacterial culture was inoculated into 4.5 mL of gastric fluid and incubated at 37°C with shaking for 1.5 h. Samples were taken at 0 h and 1.5 h. 0.5 mL of the gastric digestion sample was then inoculated into 4.5 mL of simulated intestinal fluid and incubated at 37°C with shaking for 3 h. The viable bacterial count was determined using the plate count method. The calculation formula was: initial colony count / colony count after digestion in simulated gastric or intestinal fluid.

[0056] 1.2 Analysis Results

[0057] Table 1 shows the survival rates of the bacterial strains in the simulated gastrointestinal environment. All three bacterial powders showed a survival rate of over 90% in simulated gastric fluid, with *Lactobacillus plantarum* exhibiting the highest survival rate at 105.21%, indicating its complete tolerance to gastric acid and its ability to proliferate in the simulated gastric fluid. In simulated intestinal fluid, the mixed strain had the highest survival rate at 96.59%, while *Lactobacillus acidophilus* had the lowest at 34.92%. These results indicate that *Lactobacillus acidophilus* is significantly affected by high intestinal pH and bile salts. However, the mixed strain, obtained by combining two strains, exhibits a synergistic effect, enhancing the strain's tolerance to the intestinal environment.

[0058] Table 1. Results of simulated gastrointestinal digestion

[0059]

[0060] 2. Analysis of antagonistic effects among strains

[0061] 2.1 Analytical Methods

[0062] Add OD to the culture medium 600 =0.8-1.0 The bacterial suspension in the logarithmic growth phase was evenly spread. Sterile filter paper was evenly placed on the culture medium, and 20 μL of another bacterial suspension was added to the filter paper. The mixture was incubated at 37℃ for 24 h. The appearance of inhibition zones was observed. A "+" signified the presence of an inhibition zone, indicating antagonistic activity between the two strains; a "-" signified the absence of an inhibition zone, indicating no antagonistic activity between the two strains.

[0063] 2.2 Analysis Results

[0064] The antagonistic effects of Lactobacillus acidophilus and Lactobacillus plantarum are shown in Table 2. Due to differences in strain origin, species, and characteristics, the extracellular secretions produced by the strains may have a certain inhibitory effect, thus manifesting as an antagonistic effect between strains. The results of this experiment show that there is no antagonistic effect between the two strains, which can provide a basis for subsequent strain compounding.

[0065] Table 2. Analysis of inter-strain antagonistic effects

[0066] Group Lactobacillus acidophilus Lactobacillus plantarum Lactobacillus acidophilus / - Lactobacillus plantarum - /

[0067] 3. Analysis of the adhesion ability of probiotics

[0068] 3.1 Analytical Methods

[0069] Caco-2 cells were seeded in DMEM medium containing 10% FBS and cultured at 37°C with 5% CO2. When the cells reached approximately 80% confluence, they were digested and counted. A certain number of cells were then seeded into 12-well plates containing cell spreaders. After cell adhesion, the medium was discarded, and the cells were washed 2-3 times with PBS. 1 mL of probiotic suspension was added to each well, and the plates were incubated at 37°C for 2 hours. The bacterial suspension was then removed, and the cells were washed 3 times with PBS (to remove unadhered probiotics). The cells were then fixed with 4% paraformaldehyde solution for 25 minutes, washed twice with PBS, and Gram staining was performed. The cell spreaders were then carefully removed with forceps, allowed to air dry at room temperature, and the adhesion of probiotics to Caco-2 cells was observed under a microscope.

[0070] 3.2 Analysis Results

[0071] Probiotics can competitively bind to human intestinal epithelial cells, preventing pathogenic microorganisms from colonizing these cells. According to the data in Table 3, the mixed strains showed significantly enhanced adhesion to Caco-2 cells compared to single strains.

[0072] Table 3. Adhesion ability analysis of probiotics

[0073]

[0074] 4. Analysis of in vitro blood glucose lowering ability

[0075] 4.1 Analytical Methods

[0076] (1) α-glucosidase inhibition experiment

[0077] Add 50 μL of α-glucosidase solution (1.5 U / mL) to the fermentation supernatant or bacterial strain lysate, mix well, and incubate at 37°C for 5 min. Then add 75 μL of PNPG (20 mmol / L), mix well, and continue incubation at 37°C for 15 min. Finally, add 400 μL of Na₂CO₃ (0.2 mol / L) to terminate the reaction. Measure the OD value at 405 nm using a microplate reader and calculate the inhibition rate. Each sample should be tested in at least three replicates.

[0078] (2) Assay of α-amylase inhibitory activity

[0079] Mix 200 μL of fermentation supernatant or strain fragments with 200 μL of 1% soluble starch solution and incubate at 3°C ​​for 10 min. Then add 200 μL of α-amylase working solution and continue incubation for another 10 min. Subsequently, add 400 μL of DNS and boil in a water bath for 5 min. After removal, cool in cold water, add 4 mL of deionized water, vortex to mix, and measure the OD value at 540 nm using a microplate reader.

[0080] 4.2 Analysis Results

[0081] Carbohydrates in food are mainly absorbed in the intestines in the form of monosaccharides. Ingested polysaccharides such as starch are broken down into oligosaccharides and disaccharides by α-amylase in saliva. These then need to be further broken down into glucose by α-glucosidase in the intestinal mucosa before absorption. Therefore, inhibitors of α-glucosidase and α-amylase can effectively lower blood glucose levels. This study investigated the enzyme inhibitory activity of selected strains, using the inhibition rate as an indicator to evaluate their in vitro hypoglycemic effect. Acarbose (an antidiabetic drug) was used as a positive control in the experiment. The results are shown in Table 4. The α-glucosidase inhibitory activity experiment showed that the fermentation supernatant of *Lactobacillus plantarum*, *Lactobacillus acidophilus*, and their mixed strains all had a certain inhibitory effect on α-glucosidase. When the supernatant was diluted 8 times, the mixed strains showed an inhibition rate of 82.18% on α-glucosidase, significantly higher than other strains. However, the fermentation supernatant of *Lactobacillus acidophilus* did not show significant inhibition at a 8-fold dilution, but its inhibition rate decreased to 88.27% after reducing the dilution factor. In the α-amylase inhibition experiment, the mixed strain exhibited an inhibitory activity of 98.17% (p<0.05), significantly higher than that of a single strain; while there was no significant difference in inhibitory activity between *Lactobacillus acidophilus* (86.24%) and *Lactobacillus plantarum* (84.71%). These results indicate that the combination of strains can enhance their in vitro enzyme inhibitory activity, possibly exhibiting a certain synergistic effect. Notably, the fragments of *Lactobacillus plantarum*, *Lactobacillus acidophilus*, and their mixed strains did not show inhibitory activity against these two enzymes, suggesting that their inhibitory ability mainly originates from the extracellular secretions of the strains, such as short-chain fatty acids or extracellular polysaccharides.

[0082] Table 4. In vitro hypoglycemic activity analysis

[0083]

[0084] 5. Analysis of in vitro cholesterol-lowering ability

[0085] 5.1 Analytical Methods

[0086] The test bacterial culture was inoculated into MRS-cholesterol liquid medium to achieve an initial colony count of 10-1. 8 The bacterial culture was anaerobic at 37℃ for 24 h with CFU / mL. The culture was then centrifuged at 8000 r / min for 10 min, and the supernatant was collected. The cholesterol content of the supernatant was determined by the o-phthalaldehyde method.

[0087] 5.2 Analysis Results

[0088] According to the results in Table 5, the cholesterol clearance rates of the selected strains ranged from 29.72% to 36.10%, indicating that all three bacterial powders possessed certain cholesterol-lowering abilities. Among them, the mixed strain showed the best effect, with a clearance rate of 41.27%, significantly higher than *Lactobacillus plantarum* and *Lactobacillus acidophilus* (p<0.05), suggesting a possible synergistic effect among the mixed strains. Previous studies have shown that probiotics inhibit cholesterol absorption in the intestine by hydrolyzing bile salts with bile salt hydrolases, preventing bile salts from forming micelles with cholesterol and phospholipids; or by binding to the cell membrane of probiotics, thereby achieving a cholesterol-lowering effect.

[0089] Table 5. In vitro cholesterol clearance effect of probiotics

[0090]

[0091] Example 2: Screening of prebiotic types and ratios

[0092] 1. Probiotic tropism analysis

[0093] 1.1 Analytical Methods

[0094] The test bacterial culture was inoculated at a rate of 2% into MRS medium containing different prebiotics (1% added) as the sole carbon source. The medium was incubated at 37°C with shaking. The absorbance (OD) of the fermentation broth at 600 nm was measured at 0, 6, 12, 24, 36, and 48 h. 600 MRS medium without a carbon source was used as a negative control, MRS medium with glucose as a carbon source was used as a positive control, and MRS medium without bacterial culture was used as a blank control.

[0095] 1.2 Analysis Results

[0096] This experiment investigated the growth ability of bacterial strains in culture media with different prebiotics as the sole carbon source, aiming to screen for suitable carbon sources for probiotic growth. The experimental results are as follows: Figure 1-3 As shown, the three bacterial powders exhibited better growth in fructooligosaccharides, yeast spore β-glucan, and stachyose. However, they showed almost no growth in a medium with xylooligosaccharides as the carbon source. Specifically, for mixed strains, the three best-performing prebiotics were stachyose, yeast spore β-glucan, and fructooligosaccharides; for *Lactobacillus acidophilus*, the best-performing prebiotics were fructooligosaccharides, yeast spore β-glucan, and stachyose; and for *Lactobacillus plantarum*, the best-performing prebiotics were yeast spore β-glucan, fructooligosaccharides, and stachyose. In conclusion, this experiment screened out stachyose, yeast spore β-glucan, and fructooligosaccharides as three relatively good prebiotics for further research into compound formulations.

[0097] 2. Prebiotic utilization rate analysis

[0098] The prebiotic content in the culture medium before and after fermentation was quantified using ultra-high performance liquid chromatography (UHPLC), and the utilization rate of different prebiotics by probiotics was analyzed. The experimental results are as follows: Figure 4 As shown, the mixed strains utilized stachyose and yeast spore β-glucan at significantly higher rates than the single strains (p<0.05), indicating that the combination of Lactobacillus acidophilus and Lactobacillus plantarum enhanced the utilization of prebiotics.

[0099] 3. Screening of the affinity of mixed bacterial strains for prebiotic ratios

[0100] Based on the prebiotic preference analysis results, the optimal prebiotics stachyose, fructooligosaccharide, and yeast spore β-glucan for mixed strains were selected for compounding and exploration. This experiment designed 5 ratios for compounding and exploration, with the mass ratios of stachyose, fructooligosaccharide, and yeast spore β-glucan being 1:1:1, 2:1:3, 2:3:1, 3:1:2, and 3:2:1, respectively.

[0101] 3.1 Analytical Methods

[0102] Stachyose, fructooligosaccharides, and yeast spore β-glucan were compounded in mass ratios of 1:1:1, 2:1:3, 2:3:1, 3:1:2, and 3:2:1, respectively. The test bacterial culture was inoculated at a rate of 2% into MRS medium containing different proportions of prebiotic combinations (added at 1%) as the sole carbon source. The mixture was cultured at 37°C with shaking, and the absorbance (OD) of the fermentation broth at 600 nm was measured at 0, 6, 12, 24, 36, and 48 h. 600 MRS medium without a carbon source was used as a negative control, and MRS medium with glucose as a carbon source was used as a positive control.

[0103] 3.2 Analysis Results

[0104] The analysis results are shown below. Figure 5 ,Depend on Figure 5 It can be seen that, taking into account the growth conditions in the early and late stages of proliferation, the mixed strains have the best proliferation ability when the prebiotic mass ratio is 3:2:1.

[0105] 4. Colonic fermentation analysis of different proportions of prebiotic combinations

[0106] 4.1 In vitro simulated colon fermentation experiment

[0107] (1) Preparation of fecal fermentation liquid: Collect fresh feces, add pH7.0 sterile PBS buffer at a ratio of 1:9 (w / v) to dilute, homogenize for 10 min, centrifuge the fecal mixture at 1000 rpm for 10 min to remove impurities, and keep the upper turbid liquid as fecal fermentation liquid for later use.

[0108] (2) In vitro simulated colonic fermentation experiment: 2 mL of mixed fecal suspension was added to 8.0 mL of basal nutrient medium containing 200 mg of the intervention, and the mixture was cultured anaerobically at 37 °C for 24 h. Samples were collected after 24 h, and the bacterial pellet was collected by centrifugation at 12000 rpm for 10 min. DNA was extracted according to the instructions of the fecal genomic DNA extraction kit, and the extracted DNA was diluted to 1 ng / μL. A standard curve was constructed using plasmids of successfully sequenced bacteria as standards, and qPCR detection was performed. Under the same conditions, the culture without the intervention served as the control group, the culture with inulin served as the positive control group, and the combination of different proportions of prebiotics served as the experimental group.

[0109] 4.2 Analysis Results

[0110] Experimental results are as follows Figure 6 As shown, in terms of Lactobacillus regulation, the intervention group showed significantly better results than the control group. When the ratio of prebiotics was 2:3:1 and 3:2:1, there was no significant difference compared to the positive control inulin group, but the abundance of Lactobacillus was significantly increased compared to other groups. In terms of Bifidobacterium regulation, the intervention group showed significantly better results than the control group, and the ratios of 2:3:1 and 3:2:1 significantly increased the abundance of Bifidobacterium. In terms of Akkermansia regulation, compared to other groups, the 3:2:1 ratio of prebiotics significantly increased the abundance of Akkermansia. In conclusion, a prebiotic ratio of 3:2:1 can significantly promote the upregulation of beneficial bacteria in the human gut microbiota.

[0111] Example 3: Effect of the optimal prebiotic ratio (3:2:1) on probiotic proliferation and acid production

[0112] Using a compound prebiotic consisting of stachyose, fructooligosaccharides, and yeast spore β-glucan in an optimal ratio of 3:2:1 as a carbon source, the growth and acid production of *Lactobacillus plantarum*, *Lactobacillus acidophilus*, and mixed strains were analyzed.

[0113] 1. Effect of the optimal prebiotic ratio (3:2:1) on probiotic proliferation and acid production

[0114] 1.1 Analytical Methods

[0115] The test bacterial culture was inoculated at a rate of 2% into MRS medium with the optimal prebiotic combination (added at 1%) as the sole carbon source. The medium was incubated at 37°C with shaking. The absorbance (OD) of the fermentation broth at 600 nm was measured at 0, 6, 12, 24, 36, and 48 h. 600 ) and pH.

[0116] 1.2 Analysis Results

[0117] The results are as follows Figure 7As shown in the figure, all three bacterial powders can proliferate and produce acid well in this compound prebiotic, and the OD value after fermentation is [data missing]. 600 The variation was around 1.0. During the lag and logarithmic growth phases, *Lactobacillus acidophilus* and the mixed strain showed similar growth patterns, but *Lactobacillus acidophilus* grew slightly better than the mixed strain in the later stages of fermentation. The pH decrease in this compound prebiotic was similar to its growth pattern, but the mixed strain showed a greater pH decrease than *Lactobacillus acidophilus* in the later stages of fermentation. Probiotics can proliferate and produce acid by hydrolyzing key glycosidic bonds to break down prebiotics. The different types and activities of related enzymes among different strains cause differences in their proliferation and acid production using the same carbon source.

[0118] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A synbiotic composition, characterized in that, The synbiotic composition includes probiotics and prebiotics; The probiotics are Lactobacillus acidophilus NCFM and Lactobacillus plantarum 6595; The prebiotics are stachyose, fructooligosaccharides, and yeast spore β-glucan; The mass ratio of Lactobacillus acidophilus NCFM to Lactobacillus plantarum 6595 is 1:1; The mass ratio of stachyose, fructooligosaccharide and yeast spore β-glucan is 1-3:1-3:1-3.

2. The synbiotic composition according to claim 1, characterized in that, The mass ratio of stachyose, fructooligosaccharide and yeast spore β-glucan is 2-3:2-3:

1.

3. The synbiotic composition according to claim 2, characterized in that, The mass ratio of stachyose, fructooligosaccharide and yeast spore β-glucan is 3:2:

1.

4. The synbiotic composition according to claim 1, characterized in that, The mass ratio of prebiotics to probiotics is 1:0.1-1.

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