Microbiome and metabolome in home-made fermented soybean foods of India revealed by metagenome-assembled genomes and metabolomics

Grep-chhurpi, peha, peron namsing and peruñyaan are lesser-known home-made fermented soybean foods prepared by the native people of Arunachal Pradesh in India. Present work aims to study the microbiome, their functional annotations, metabolites and recovery of metagenome-assembled genomes (MAGs) in these four fermented soybean foods. Metagenomes revealed the dominance of bacteria (97.80 %) with minor traces of viruses, eukaryotes and archaea. Bacillota is the most abundant phylum with Bacillus subtilis as the abundant species. Metagenome also revealed the abundance of lactic acid bacteria such as Enterococcus casseliflavus, Enterococcus faecium, Mammaliicoccus sciuri and Staphylococcus saprophyticus in all samples. B. subtilis was the major species found in all products. Predictive metabolic pathways showed the abundance of genes associated with metabolisms. Metabolomics analysis revealed both targeted and untargeted metabolites, which suggested their role in flavour development and therapeutic properties. High-quality MAGs, identified as B. subtilis, Enterococcus faecalis, Pediococcus acidilactici and B. velezensis, showed the presence of several biomarkers corresponding to various bio-functional properties. Gene clusters of secondary metabolites (antimicrobial peptides) and CRISPR-Cas systems were detected in all MAGs. This present work also provides key elements related to the cultivability of identified species of MAGs for future use as starter cultures in fermented soybean food product development. Additionally, comparison of microbiome and metabolites of grep-chhurpi, peron namsing and peruñyaan with that of other fermented soybean foods of Asia revealed a distinct difference.

Comprehensive bacterial-metabolite profiles of Hawaijar, Bekang, and Akhone: a comparative study on traditional fermented soybeans of north-east India

Preparation of traditionally fermented soybeans varies across ethnicities with distinct tastes, flavour, and nutritional values. The fermented soybean varieties Hawaijar, Bekang, and Akhone of north-east India are associated with diverse ethnic groups from Manipur, Mizoram, and Nagaland, respectively. These varieties differ in substrate and traditional practice that exerts differential bacterial-metabolite profile, which needs an in-depth analysis i. Culture-dependent and independent techniques investigated the bacterial diversity of the fermented soybean varieties. Gas chromatography and mass spectroscopy (GC-MS) studied these varieties' metabolite profiles. The common dominant bacterial genera detected in Hawaijar, Bekang, and Akhone were Bacillus, Ignatzschinaria, and Corynebacterium, with the presence of Brevibacillus and Staphylococcus exclusively in Hawaijar and Oceanobacillus in Bekang and Akhone. The metabolite analysis identified a higher abundance of essential amino acids, amino and nucleotide sugars, and vitamins in Hawaijar, short-chain fatty acids in Bekang, polyunsaturated fatty acids in Akhone and Hawaijar, and prebiotics in Akhone. The bacteria-metabolite correlation analysis predicted four distinct bacterial clusters associated with the differential synthesis of the functional metabolites. While B. subtilis is ubiquitous, cluster-1 comprised B. thermoamylovorans/B. amyloliquefaciens, cluster-2 comprised B. tropicus, cluster-3 comprised B. megaterium/B. borstelensis, and cluster-4 comprised B. rugosus. To the best of our knowledge, this is the first comparative study on traditional fermented soybean varieties of north-east India linking bacterial-metabolite profiles which may help in designing starters for desired functionalities in the future.

Quality characteristics of soybean fermented by Mucor, Rhizopus, and Aspergillus from meju

Three candidate starter strains-Aspergillus oryzae SNU-G, Mucor sp. KACC 46077, and Rhizopus oryzae KACC 40256-were inoculated into soybean, as individual strains or in combination, to assess their roles in fermentation. All the strains increased the pH, amino-type nitrogen, and moisture content of the soybean during fermentation, and decreased the lightness, redness, and yellowness. The inoculated strains increased to an average density of 1.37 × 10⁸ spores/g (from the initial 5.0 × 10⁷ spores/g) after 20 days of fermentation. Forty-two volatile compounds, including an acid, alcohols, carbonyls, furans, and a pyrazine, were more abundant in soybean fermented with starters than in controls. A. oryzae SNU-G increased the pH more than the other strains and produced more volatile alcohol compounds. R. oryzae KACC 40256 resulted in the lowest reduction of redness and yellowness during the fermentation and produced large amounts of carbonyl compounds, including two specific volatile compounds, 2-hydroxy-3-methylcyclopent-2-en-1-one and (3E)-3-ethyl-2-methylhexa-1,3-diene. Mucor sp. KACC 46077 contributed the least to pH change and volatile compound production, and did not produce specific volatile compounds. Although no significant synergy in the production of volatile compounds was found when using mixtures of strains compared with application of single strains, the quality of fermented soybeans was confirmed to be different depending on the strain(s) applied.

Characterization of Bacillus subtilis bacteriophage BasuTN3 isolated from Thua Nao, a thai fermented soybean food product

The infection of bacteriophage is of great concern in food industry as this can result in complete fermentation failure. In this study, a virulent bacteriophage, named BasuTN3, was isolated from Thua Nao, a Thai fermented soybean. The stability of BasuTN3 was evaluated under various ranges of temperature, pH, chloroform, UV, and disinfectants. The results showed that the isolated BasuTN3 appeared to be specific to its bacterial host, which was identified as Bacillus subtilis strain TN3 based on the 16 S rRNA gene sequence analysis. Under TEM, the BasuTN3 belonged to the family Myoviridae. The isolated BasuTN3 could withstand wide temperature ranges (4-45 °C) and pH conditions (5-11). The BasuTN3 was susceptible to chloroform, UV, and commonly used disinfectants. The results obtained expand the knowledge of the Bacillus bacteriophage diversity in the fermented soybean products and provide useful information for the bacteriophage and its bacterial starter cultures.

Fermented soybean meal modified the rumen microbiome to enhance the yield of milk components in Holstein cows

The study was conducted to evaluate the rumen microbiota as well as the milk composition and milk component yields of Holstein cows supplemented with fermented soybean meal (FSBM). Eighteen Holstein cows in their 2nd parity with 54.38 ± 11.12 SD days in milking (DIM) were divided into two dietary groups (CON and TRT) of nine cows per group. The cows in the TRT group received 300 g of FSBM per cow per day in addition to the conventional diet, while each cow in the CON group was supplemented with 350 g of soybean meal (SBM) in their diet daily throughout the 28-day feeding trial. Rumen bacterial composition was detected via 16S rRNA sequencing, and the functional profiles of bacterial communities were predicted. Milk composition, milk yield, as well as rumen fermentation parameters, and serum biochemistry were also recorded. The inclusion of FSBM into the diets of Holstein cows increased the milk urea nitrogen (MUN), milk protein yield, fat corrected milk (FCM), and milk fat yield while the milk somatic cell count (SCC) was decreased. In the rumen, the relative abundances of Fibrobacterota, and Spirochaetota phyla were increased in the TRT group, while the percentage of Proteobacteria was lower. In addition, the supplementation of FSBM to Holstein cows increased the acetate percentage, rumen pH, and acetate to propionate ratio, while the proportion of propionate and propionate % was observed to decrease in the TRT group. The KEGG pathway and functional prediction revealed an upregulation in the functional genes associated with the biosynthesis of amino acids in the TRT group. This enrichment in functional genes resulted in an improved synthesis of several essential amino acids including lysine, methionine, and branch chain amino acids (BCAA) which might be responsible for the increased milk protein yield. Future studies should employ shotgun metagenomics, transcriptomics, and metabolomics technology to investigate the effects of FSBM on other rumen microbiomes and milk protein synthesis in the mammary gland in Holstein cows. KEY POINTS: • The supplementation of fermented soybean meal (FSBM) to Holstein cows modified the proportion of rumen bacteria. • Predicted metabolic pathways and functional genes of rumen bacteria revealed an enrichment in pathway and genes associated with biosynthesis of amino acids in the group fed FSBM. • The cows supplemented with FSBM record an improved rumen fermentation. • Cows supplemented with FSBM recorded an increased yield of milk protein and milk fat.

Fermented soybean foods: A review of their functional components, mechanism of action and factors influencing their health benefits

After thousands of years of evolution and development, traditional fermented soybean foods, with their unique charm, have gained a stable place in the global market. With the explosive development of modern biological technologies, some traditional fermented soybean foods that possess health-promoting benefits are gradually appearing. Physiologically active substances in fermented soybean foods have received extensive attention in recent decades. This review addresses the potential health benefits of several representative fermented soybean foods, as well as the action mechanism and influencing factors of their functional components. Phenolic compounds, low-molecular-weight peptides, melanoidins, furanones and 3-hydroxyanthranilic acid are the antioxidative components predominantly found in fermented soybean foods. Angiotensin I-converting enzyme inhibitory peptides and γ-aminobutyric acid isolated from fermented soy foods provide potential selectivity for hypertension therapy. The potential anti-inflammatory bioactive components in fermented soybean foods include γ-linolenic acid, butyric acid, soy sauce polysaccharides, 2S albumin and isoflavone glycones. Deoxynojirimycin, genistein, and betaine possess high activity against α-glucosidase. Additionally, fermented soybean foods contain neuroprotective constituents, including indole alkaloids, nattokinase, arbutin, and isoflavone vitamin B12. The anticancer activities of fermented soybean foods are associated with surfactin, isolavone, furanones, trypsin inhibitors, and 3-hydroxyanthranilic acid. Nattokinase is highly correlated with antioxidant activity. And a high level of menaquinones-7 is linked to protection against neurodegenerative diseases. Sufficiently recognizing and exploiting the health benefits and functional components of traditional fermented soybean foods could provide a new strategy in the development of the food fermentation industry.

Safety and Technological Characterization of Staphylococcus xylosus and Staphylococcus pseudoxylosus Isolates from Fermented Soybean Foods of Korea

We evaluated the antibiotic susceptibilities, hemolytic activities, and technological properties of 36 Staphylococcus xylosus strains and 49 S. pseudoxylosus strains predominantly isolated from fermented soybean foods from Korea. Most of the strains were sensitive to chloramphenicol, erythromycin, gentamycin, kanamycin, lincomycin, oxacillin, tetracycline, and trimethoprim. However, 23 strains exhibited potential phenotypic acquired resistance to erythromycin, lincomycin, and tetracycline. Based on breakpoint values for staphylococci from the Clinical and Laboratory Standards Institute, >30% of the isolates were resistant to ampicillin and penicillin G, but the population distributions in minimum inhibitory concentration tests were clearly different from those expected for acquired resistance. None of the strains exhibited clear α- or β-hemolytic activity. S. xylosus and S. pseudoxylosus exhibited salt tolerance on agar medium containing 20% and 22% (w/v) NaCl, respectively. S. xylosus and S. pseudoxylosus strains possessed protease and lipase activities, which were affected by the NaCl concentration. Protease activity of S. pseudoxylosus was strain-specific, but lipase activity might be a characteristic of both species. This study confirms the potential of both species for use in high-salt soybean fermentation, but the safety and technological properties of strains must be determined to select suitable starter candidates.

Fermented soybean enhances post-meal response in appetite-regulating hormones among Indonesian girls with obesity

OBJECTIVE

To assess the post-meal response in appetite-regulating hormones acyl-ghrelin and insulin after fermented soybean (tempeh) consumption in girls with obesity.

METHODS

A randomized counter-balanced crossover study was conducted using a breakfast (307 kcal, protein: 28%, fat: 23%, and carbohydrate: 55%) containing fermented soybean or isocaloric non-fermented soybean among 13 females (aged 18-20 y; BMI 25-30) after an overnight fast. The outcome variables were plasma acyl-ghrelin, insulin, arginine and score of the visual analog scale (VAS) appetite questionnaire.

RESULTS

While no change was observed after the non-fermented soybean meal, plasma acyl-ghrelin decreased by 35% at 30 min and remained below baseline until 120 min after the fermented soybean meal (P < 0.05). Plasma insulin increased after consumption of both meals and fermented soybean meal-induced 30% greater response in insulin at 120 min than non-fermented soybean meal (P < 0.05). Circulating arginine levels were slightly greater (24%) at 120 min after the fermented soybean meal than the non-fermented soybean meal (P < 0.05). No difference in subjective appetite was observed between the fermented soybean meal and the non-fermented soybean meal.

CONCLUSIONS

Fermented soybean meal induced greater response in appetite-regulating hormones compared with non-fermented soybean meal. No difference in post-meal satiety feeling between fermented and non-fermented soybean meal suggests poor sensitivity of the brain to the appetite-regulating hormones among girls with obesity.

Metabolic tracking of isoflavones in soybean products and biosamples from healthy adults after fermented soybean consumption

Fermentation may enhance the nutritional properties of foods by increasing metabolite bioactivity or bioavailability. This study explored the effect of fermentation on isoflavone bioavailability and metabolism. Isoflavone metabolites were tracked in foods and biospecimens of healthy adults after fermented soybean (FS) or non-fermented soybean (NFS) consumption in a randomized, controlled, crossover intervention study. The change in soybean isoflavones caused by fermentation resulted in faster absorption and higher bioavailability after consumption of FS. Although the urinary level of total isoflavone metabolites was similar after the consumption of the two diets, urinary genistein 7-O-sulfate was derived as a discriminant metabolite for the FS diet by partial least squares discriminant analysis. This study suggests that an isoflavone conjugate profile might be a more appropriate marker than total isoflavone levels for discriminating between the consumption of FS and NFS diets.

Small double-stranded RNA with anti-HIV activity abundantly produced by Bacillus subtilis MTCC5480 isolated from fermented soybean

Anti-viral RNA therapy is on high demand nowadays due to the emergence of several new viral infections. The small non-coding regulatory RNAs (dsRNA) from the microbial sources are not yet explored for anti-viral activity. In this study, we assessed the anti-HIV activity of the small dsRNA produced by 12 different microbial species isolated from naturally fermented foods of North-East India. For this, we selectively extracted the dsRNA from the microbial culture, confirmed its double-stranded nature by immunoblotting, and deep sequenced the cDNA library using Illumina platform. Further, we used conventional algorithms to predict the potential targets of the dsRNA sequences within the 3'-UTR region of HIV-1. A small dsRNA fragment with 34 bases in size with a sequence of 3'-UUGGUACACGAGAUGGUUCGACUCGAUGAAGGGC-5' produced abundantly (9.17% of the total dsRNA fraction) by Bacillus subtilis MTCC5480 showed a much higher base complementarity values than previously reported miRNAs analysed against HIV-1. We separated the dsRNA fraction and validated the anti-HIV activity against human peripheral blood mononuclear cells (PBMC) infected with JRCSF strain of HIV-1 virus and the EC50 value ranges from 0.2-0.3 μM. This small dsRNA abundantly produced by B. subtilis could be studied further for its application as an anti-viral therapeutic agent.

Proteomic study of bioactive peptides from tempe

Tempe is a traditional Indonesian fermented soybean mostly produced in small industries and sold locally throughout the country. Studies on the bioactive peptides in tempe are rare. Here, we studied bioactive peptides in samples from three tempe producers with different degrees of sanitation. The peptide sub-fractions of tempe from each producer were collected following water extraction, ultrafiltration (<3 kDa), gel filtration chromatography, and reversed phase-high performance liquid chromatography (RP-HPLC) separation followed by liquid chromatography-mass spectrometry (LC-MS). The MS spectra were then predicted using FindPept tools, and their biofunctionalities were confirmed with BIOPEP databases. There were few similar peptides found in tempe from the three producers. Peptides Val-His and Ala-Leu-Glu-Pro were found in tempe from all producers. Producers having a good sanitation level had more bioactive peptides than those with moderate or poor sanitation levels (58%, 43% and 35%, from good to poor sanitation). This work showed that the tempe from the three producers had antihypertensive, antidiabetic, antioxidative and antitumor peptides.

Microbial diversity and chemical analysis of Shuidouchi, traditional Chinese fermented soybean

Shuidouchi is a traditional Chinese fermented soybean product and its quality is largely affected by the microbes involved in the fermentation. In this study, eleven Shuidouchi samples were collected from southwest China and the microbial diversity and its correlations with chemical characteristics were investigated. Bacterial community was detected using 16S rRNA sequencing, along with bacterial and fungal viable plate counts. Biogenic amines and other chemical characteristics were determined by HPLC and corresponding chemical reaction methods. Among eleven Shuidouchi samples, 21 phyla and 356 genera were identified. Firmicutes, Bacteroidetes and Proteobacteria were the predominant phyla while Bacillus, Bacteroides and Lactobacillus were the main genera. The average cell number of bacteria, lactic acid bacteria and fungi were 1.6 × 106, 5.9 × 104 and 7.6 × 103 CFU/g, respectively. HPLC results showed that the mean concentration of tryptamine, β-phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine and spermine were 23.11, 3.66, 12.21, 7.12, 8.13, 22.98, 24.72, and 39.00 mg/kg, respectively. The average content of other characteristics including amino acid nitrogen, titratable acidity, and reducing sugar were 2.08, 3.44, and 25.78 g/kg, respectively. Shuidouchi samples were slightly acidic or neutral. Fibrinolytic enzyme activity was detected only in one sample. Among top 52 identified genera, 9 genera showed positive correlations with the chemical characteristics of Shuidouchi while 15 genera were negatively associated. Our results indicated that Shuidouchi contained rich microbial resources and were edible safety based on the tested indexes. The associations identified between microbes and chemical characteristics could be further utilized in the food fermentation industry.

Comparison of antioxidants potential, metabolites, and nutritional profiles of Korean fermented soybean (Cheonggukjang) with Bacillus subtilis KCTC 13241

This study was carried out to determine the effect of different concentrations of Bacillus subtilis (0, 1, 3, 5, and 7%) on the antioxidant potential and biochemical constituents of traditional Korean fermented soybean, Cheonggukjang (CKJ). The antioxidant capacity was studied using the reducing power, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) assays and the total phenolic contents (TPC) were measured using the Folin-Ciocalteu method. CKJ prepared using 1% B. subtilis revealed the highest TPC (5.99 mg/g), total amino acids (7.43 mg/g), DPPH (94.24%), and ABTS (86.03%) radical-scavenging activity and had the highest value of palmitic acid (11.65%), stearic acid (2.87%), and linolenic acid (11.76%). Results showed that the calcium, iron, sodium, and zinc contents increased in the CKJ prepared using 7% B. subtilis from 1481.38 to 1667.32, 41.38 to 317.00, 48.01 to 310.07, and 32.82 to 37.18 mg/kg respectively. In conclusion, the present results indicate that the fermentation of soybean with B. subtilis (KCTC 13241) significantly augments the nutritional and antioxidant potential of CKJ and it can be recommended as a health-promoting food source.

Improvement of nutritional components and in vitro antioxidative properties of soy-powder yogurts using Lactobacillus plantarum

This research was the first to demonstrate changes in nutritional compositions (isoflavone and CLA) from the 50% methanol extracts of soy-powder milk (SPM) and soy-powder yogurt (SPY) through fermentation using Lactobacillus plantarum S48 and P1201 strains. The radical scavenging activities and protective effects against oxidative stress in LLC-PK₁ cells were also investigated. The average physicochemical characteristics including acidity and viable cell number as well as β-glucosidase activity increased with 0.2 → 0.7%, 7.5 → 9.8 log cfu/mL, and 0.0 3 → 1.75 U/g in SPYs. Total average isoflavones were considerably reduced (3180.3 → 2018.3 μg/g) with the increase of aglycone contents (191.8 → 770.2 μg/g), especially, daidzein exhibited the most remarkable increase rate (98.6 → 460.9 μg/g; > 4.8 times) during fermentation. The CLA and total phenolics also increased with significant differences (ND → 1.6 mg/g; 2.4 → 3.6 mg/GAE/g) between SPM and SPY. Interestingly, the cis-9, trans-11 CLA showed approximately 90% in total content. Moreover, the scavenging capacities against three radicals markedly increased with about 30% in SPYs, as the following order: ABTS > hydroxyl > DPPH. The protective effects on oxidative stress (py-rogallol: O2-, SNP: NO, and SIN-1: ONOO⁻) were also observed high cell viabilities (>10%) under LLC-PK₁ cellular system. Our results suggest that SPY may be utilized as a potent source regarding natural antioxidants and beneficial components for health food and medical uses.

Douchi (fermented Glycine max Merr.) alleviates atopic dermatitis-like skin lesions in NC/Nga mice by regulation of PKC and IL-4

BACKGROUND

Douchi (fermented Glycine max Merr.) is produced from fermented soybeans, which is widely used in traditional herbal medicine. In this study, we investigated whether Douchi attenuates protein kinase C (PKC) and interleukin (IL)-4 response and cutaneous inflammation in Atopic dermatitis (AD)-like NC/Nga mice.

METHODS

To induce AD-like skin lesions, D. farinae antigen was applied to the dorsal skin of 3-week-old NC/Nga mice. After inducing AD, Douchi extract was administered 20 mg/kg daily for 3 weeks to the Douchi-treated mice group. We identified the changes of skin barrier and Th2 differentiation through PKC and IL-4 by immunohistochemistry.

RESULTS

Douchi treatment of NC/Nga mice significantly reduced clinical scores (p < 0.01) and histological features. The levels of PKC and IL-4 were significantly reduced in the Douchi-treated group (p < 0.01). The reduction of IL-4 and PKC led to decrease of inflammatory factors such as substance P, inducible nitric oxide synthase (iNOS) and Matrix metallopeptidase 9 (MMP-9) (all p < 0.01). Douchi also down-regulated Th1 markers (IL-12, TNF-α) as well as Th2 markers (IL-4, p-IκB) (p < 0.01).

CONCLUSION

Douchi alleviates AD-like skin lesions through suppressing of PKC and IL-4. These results also lead to diminish levels of substance P, iNOS and MMP-9 in skin lesions. Therefore, Douchi may have potential applications for the prevention and treatment of AD.

Soluble extract of soybean fermented with Aspergillus oryzae GB107 inhibits fat accumulation in cultured 3T3-L1 adipocytes

BACKGROUND/OBJECTIVES

This study was conducted to investigate the effects of fermented soybean (FS) extract on adipocyte differentiation and fat accumulation using cultured 3T3-L1 adipocytes.

MATERIALS/METHODS

3T3-L1 adipocytes were treated with FS and nonfermented soybean (NFS) extract during differentiation for 10 days in vitro. Oil red O staining was performed and glycerol-3-phosphate dehydrogenase (GPDH) activity was measured for analysis of fat accumulation. Expressions of adipogenic genes were measured.

RESULTS

Soluble extract of soybean fermented with Aspergillus oryzae GB107 contained higher levels of low-molecular-weight protein than conventional soybean protein did. FS extract (50 µg/ml) inhibited adipocyte differentiation and fat accumulation during differentiation of 3T3-L1 preadipocytes for 10 days in vitro. Significantly lower GPDH activity was observed in differentiated adipocytes treated with the FS extract than those treated with NFS extract. Treatment with FS extract resulted in decreased expression levels of leptin, adiponectin, and adipogenin genes, which are associated with adipogenesis.

CONCLUSIONS

This report is the first to demonstrate that the water-soluble extract from FS inhibits fat accumulation and lipid storage in 3T3-L1 adipocytes. Thus, the soybean extract fermented with A. oryzae GB107 could be used to control lipid accumulation in adipocytes.

Fermented soybeans by Rhizopus oligosporus reduce femoral bone loss in ovariectomized rats

BACKGROUND/OBJECTIVES

Soy isoflavones are structurally similar to estrogen and bind to estrogen receptors, suggesting that they exhibit estrogenic activities; therefore, they are referred to as phytoestrogens. Fermentation may affect the bioavailability of isoflavones altering soy isoflavone glycosides in the form of aglycones. Thus, this study investigated the effects of fermented soybeans by Rhizopus oligosporus on bone metabolism in both young rats as a pilot test and in ovariectomized (ovx) old rats as a model of menopause.

MATERIALS/METHODS

In the pilot test, a total of 24 seven-week-old female Sprague-Dawley (SD) rats were fed one of three diets for a period of four weeks: casein, unfermented soybean product, or fermented soybean product by R. oligosporus. In the ovx rat model, 20-week-old SD rats weighing 260-290 g underwent either sham-operation (n = 10) or bilateral ovariectomy (n = 30) and were then fed the AIN-93M diet for one week. Thereafter, rats were fed sham-casein, ovx-casein, ovx-soybean, or ovx-fermented soybean diet for five weeks. After decapitation, femoral bones were isolated and preserved in 9% formalin for assessment of bone mineral density (BMD), bone mineral content (BMC), and bone-breaking strength (BBS).

RESULTS

Ovx rats showed significantly increased weight gain and decreased uterine wet weight. Of particular interest, ovx rats fed fermented soybeans showed increased uterine wet weights compared to control rats. Fermented soybean diet caused a significant increase in plasma 17-β estradiol concentrations in young rats, and 17-β estradiol levels were enhanced in ovx rats to match those of sham-operated ones. Significantly lower femoral BMD and BMC were observed in ovx rats compared to sham-operated controls, whereas bone areas did not differ statistically among the groups. In addition, BBS tended to be increased in ovx rats fed soybeans and fermented soybeans.

CONCLUSIONS

Supplementation of fermented soybeans could have preventive and therapeutic effects against osteoporosis in postmenopausal women.