Soybean meal (SBM) prepared by soybean crushing is the most popular protein source in the poultry and livestock industries (Cai et al., 2015) due to its economic manufacture, high protein content, and good nutritional value. Despite these benefits, SBM contains various antigen proteins such as glycinin and β-conglycinin, which account for approximately 70% of the total proteins of the SBM and reduce digestibility and damage intestinal function (Peng et al., 2018). Treating SBM with proteases (neutrase, alcalase, and trypsin) or fermentation can eliminate these antigen proteins (Contesini et al., 2018). Because of its safety and rapid growth cycle, Bacillus strains are considered ideal for the fermentation industry (Yao et al., 2021). SBM fermented by Bacillus yields products with high nutritional value and low levels of antinutritional factors (ANFs), stimulating research in this area (Yuan et al., 2017). Kumari et al. (2023) demonstrated that fermentation with Bacillus species effectively degrades antigen proteins and increases crude protein content. The degradation of antigen proteins relies on protease hydrolysis. Low protease production is the major obstacle hindering the widespread use of microbial fermentation techniques.
Bacillus amyloliquefaciens/metabolism* ; Fermentation ; Glycine max/metabolism* ; Soybean Proteins/metabolism* ; Peptide Hydrolases/metabolism* ; Ribosomes/metabolism* ; Globulins ; Antigens, Plant ; Seed Storage Proteins

PURPOSE: Clinical trials have studied the use of soy protein for treating type 2 diabetes (T2D) and metabolic syndrome (MS). The purpose of this study was to outline evidence on the effects of soy protein supplementation on clinical indices in T2D and MS subjects by performing a meta-analysis of randomized controlled trials (RCTs). MATERIALS AND METHODS: We searched PubMed, EMBASE, and Cochrane databases up to March 2015 for RCTs. Pooled estimates and 95% confidence intervals (CIs) were calculated by the fixed-and-random-effects model. A total of eleven studies with eleven clinical variables met the inclusion criteria. RESULTS: The meta-analysis showed that fasting plasma glucose (FPG) [weighted mean difference (WMD), -0.207; 95% CI, -0.374 to -0.040; p=0.015], fasting serum insulin (FSI) (WMD, -0.292; 95% CI, -0.496 to -0.088; p=0.005), homeostasis model of assessment for insulin resistance index (HOMA-IR) (WMD, -0.346; 95% CI, -0.570 to -0.123; p=0.002), diastolic blood pressure (DBP) (WMD, -0.230; 95% CI, -0.441 to -0.019; p=0.033), low-density lipoprotein cholesterol (LDL-C) (WMD, -0.304; 95% CI, -0.461 to -0.148; p=0.000), total cholesterol (TC) (WMD, -0.386; 95% CI, -0.548 to -0.225; p=0.000), and C-reactive protein (CRP) (WMD, -0.510; 95% CI, -0.722 to -0.299; p=0.000) are significant reduced with soy protein supplementation, compared with a placebo control group, in T2D and MS patients. Furthermore, soy protein supplementation for longer duration (≥6 mo) significantly reduced FPG, LDL-C, and CRP, while that for a shorter duration (<6 mo) significantly reduced FSI and HOMA-IR. CONCLUSION: Soy protein supplementation could be beneficial for FPG, FSI, HOMA-IR, DBP, LDL-C, TC, and CRP control in plasma.
Aged ; Blood Glucose/*metabolism ; Blood Pressure ; C-Reactive Protein/metabolism ; Cardiovascular Diseases/prevention & control ; Cholesterol/blood ; Diabetes Mellitus, Type 2/blood/*therapy ; *Dietary Supplements ; Humans ; Lipids/blood ; Metabolic Syndrome X/*blood/prevention & control ; Randomized Controlled Trials as Topic ; Soybean Proteins/*administration & dosage ; *Soybeans

By now, the digestive stability experiments provided by most authoritative organizations are in vitro tests. Evaluating the protein digestive stability with in vivo models should be more objective. The present study aimed to verify the in vivo digestibility of soybean β-conglycinin β-subunit in Wuzhishan (WZS) minipigs. Three minipigs were surgically fitted with O-stomach and T-ileum cannulae and fed with soybean meals. According to SDS-PAGE, the 50 kD fraction of soybean β-conglycinin β-subunit persisted in the gastric fluid until 6 h after feeding, which was detected at 3 h and clearly visible at 4-6 h in the intestinal fluid. Western blot with anti-β-conglycinin β-subunit McAb confirmed it.
Animals ; Antigens, Plant ; chemistry ; metabolism ; Digestion ; physiology ; Globulins ; chemistry ; metabolism ; Male ; Protein Subunits ; chemistry ; metabolism ; Seed Storage Proteins ; chemistry ; metabolism ; Soybean Proteins ; chemistry ; metabolism ; Swine ; Swine, Miniature ; physiology

OBJECTIVETo explore the effect of Se-riched soybean peptide (SSP) on antioxidant function in rats of fatty liver caused by high-fat diet.

METHODSForty Wistar rats were divided into 4 groups randomly and fed with standard diet and water (NC), high-fat diet and water (HC), high-fat diet and SSP (0.1 g/d) (SeH), standard diet and SSP (0.1 g/d) (SeN) respectively. After 10 weeks, the rats were killed to investigate the pimelosis level in liver tissues by Sudan III staining and the expression of hepatic GRP78 by immunohistochemical analysis. We also analyzed the changes of liver function, blood lipid, the glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in livers and serum.

RESULTSThe pimelosis level, total cholesterol (TC), triglyceride (TG), MDA contents and the expression of GRP78 in HC group were significantly higher than those in NC, SeN, SeH groups. The activities of GSH-Px and SOD in liver and serum were markedly up-regulated in SeH (P < 0.01). There was no significant difference between NC and SeN groups.

CONCLUSIONSSP can improve liver cell injury and the antioxidant functions in rats with fatty liver effectively and decrease the expression of GRP78 in liver.

Animals ; Antioxidants ; metabolism ; Diet, High-Fat ; adverse effects ; Disease Models, Animal ; Fatty Liver ; chemically induced ; metabolism ; Heat-Shock Proteins ; metabolism ; Liver ; drug effects ; metabolism ; Male ; Rats ; Rats, Wistar ; Selenium ; pharmacology ; Soybean Proteins ; pharmacology ; Soybeans ; chemistry

OBJECTIVETo observe the effect of the postpone in skeletal muscle aging process of D-galactose rats by weight training and soy polypeptide supplement in 6 weeks, and discuss the initial mechanism.

METHODSixty male SD rats (three month old)were randomly assigned: 6 week control (C6,) and 6 week model (M6) 6 for each group, 12 week model (M12), big load (B12), small load (S12), peptide (P12), peptide + big load (PB12) and peptide + small load group (PS12) 8 for each group, eight fourteen month rats were taken in the natural aging group. The rats were killed by the end of 6th week and 12th week, tested the indicators.

RESULTCompare with group C6, the indicators in group M6 showed aging in different levels; Compare with group M12, weight training or soy polypeptide supplement in all intervention groups could increase the content of skeletal muscle superoxide dismutase (SOD), SOD/MDA, the serum growth hormone(GH), insulin-like growth factor-1 (IGF-I)and skeletal muscle IGF-I mRNA, decreased the malondialdehyde (MDA) content of skeletal muscle, and they had notable interaction.

CONCLUSIONRat skeletal muscle aging model can be copied successfully by D-galactose hypodermic, and go on with 6-week weight training or soy polypeptide supplement, they can postpone the skeletal muscle aging process of D-galactose rats, and the two interference way united can have more obvious effect. Its preliminary mechanism may be related to the reduction of skeletal muscle oxidative stress and lipid peroxidation, the correction of hormones and related factors metabolic disorders, the elevation of skeletal muscle IGF-I mRNA expression and so on.

Aging ; physiology ; Animals ; Galactose ; Growth Hormone ; blood ; Insulin-Like Growth Factor I ; metabolism ; Male ; Malondialdehyde ; metabolism ; Muscle, Skeletal ; drug effects ; physiology ; Physical Conditioning, Animal ; physiology ; Rats ; Rats, Sprague-Dawley ; Soybean Proteins ; pharmacology ; Soybeans ; chemistry ; Superoxide Dismutase ; metabolism

This study was aimed to investigate whether soy protein hydrolysates had beneficial effects on serum and tissue lipid contents and appetite-related hormones as compared with intact soy protein. Four-week-old male Sprague-Dawley rats were fed AIN-93M diet containing high fat (18% w/w) with low protein (10% w/w). After four weeks, the rats were divided into four groups (n = 8/group) and fed experimental diets with different nitrogen sources and levels, respectively; 10% soy protein isolate (10SPI), 25% soy protein isolate (25SPI), 25% soy protein hydrolysates (25SPH) and 25% soy macro-peptide fractions (25SPP, MW > or = 10,000) for six weeks. Weight gain was significantly higher in 25% nitrogen sources-fed groups than in 10% group (10SPI). In 25SPP, perirenal fat mass and serum total lipid were significantly lower than in other groups. As for appetite-related hormones, serum ghrelin concentration was not shown to be different among groups but leptin concentration was significantly decreased in 25SPP. It can be concluded that soy macro-peptide fractions as compared with intact soy protein may have beneficial effects on reducing fat mass and serum lipid.
Animals ; Appetite ; Diet ; Ghrelin ; Humans ; Leptin ; Lipid Metabolism ; Male ; Nitrogen ; Rats ; Rats, Sprague-Dawley ; Soybean Proteins ; Weight Gain

During carcinogenesis, NF-kappaB mediates processes associated with deregulation of the normal control of proliferation, angiogenesis, and metastasis. Thus, suppression of NF-kappaB has been linked with chemoprevention of cancer. Accumulating findings reveal that heat shock protein 90 (HSP90) is a molecular chaperone and a component of the IkappaB kinase (IKK) complex that plays a central role in NF-kappaB activation. HSP90 also stabilizes key proteins involved in cell cycle control and apoptosis signaling. We have determined whether the exogenous administration of isoflavone-deprived soy peptide prevents 7,12-dimethylbenz[alpha]anthracene (DMBA)-induced rat mammary tumorigenesis and investigated the mechanism of action. Dietary administration of soy peptide (3.3 g/rat/day) significantly reduced the incidence of ductal carcinomas (50%), the number of tumors per multiple tumor-bearing rats (49%; P < 0.05), and extended the latency period of tumor development (8.07 +/- 0.92 weeks) compared to control diet animals (10.80 +/- 1.30; P < 0.05). Our results have further demonstrated that soy peptide (1) dramatically inhibits the expression of HSP90, thereby suppressing signaling pathway leading to NF-kappaB activation; (2) induces expression of p21, p53, and caspase-3 proteins; and (3) inhibits expression of VEGF. In agreement with our in vivo data, soy peptide treatment inhibited the growth of human breast MCF-7 tumor cells in a dose-dependent manner and induced apoptosis. Taken together, our in vivo and in vitro results suggest chemopreventive and tumor suppressive functions of isoflavone-deprived soy peptide by inducing growth arrest and apoptosis.
9,10-Dimethyl-1,2-benzanthracene ; Adenocarcinoma/*prevention & control ; Animals ; Apoptosis/*drug effects ; Breast Neoplasms/chemically induced/pathology/*prevention & control ; Cell Line, Tumor ; Chemoprevention ; Female ; Gene Expression Regulation, Neoplastic ; HSP90 Heat-Shock Proteins/genetics/metabolism ; Humans ; Isoflavones/chemistry ; NF-kappa B/genetics/metabolism ; Peptides/chemistry/isolation & purification/therapeutic use ; Rats ; Rats, Sprague-Dawley ; Soybean Proteins/chemistry/*isolation & purification/*therapeutic use ; Soybeans/chemistry

This study was conducted to investigate the effect of soy protein hydrolyzate on lipid metabolism and antioxidant activity in the rat. Thirty-eight male rats of Sprague-Dawley strain were divided into five groups: casein, isolated soy protein (ISP), seoritae protein hydrolyzate (SH), soluble soy protein hydrolyzate (SS), and insoluble soy protein hydrolyzate (IS). The control diet (casein group) contained 20% casein protein and experimental diet contained 10% casein and 10% isolated soy-protein or soy-protein hydrolyzate. Fecal lipid content was increased and lipid apparent absorption rate was decreased significantly by the ISP group at the first week of experimental period. Blood triglyceride, total cholesterol, LDL-cholesterol and atherogenic index (AI) were decreased by soy protein hydrolyzate groups than casein group. Liver total lipid, triglyceride and cholesterol were not different among groups, but showed decreasing tendencies in soyprotein hydrolyzate groups. The lipid lowering effect was prominent in the IS group among soy protein hydrolyzate groups. Total antioxidant activity showed increasing tendency in the seoritae hydrolyzate group. Liver superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase activities also showed higher tendencies in the seoritae hydrolyzate group than other groups. In conclusion, insoluble soyprotein hydrolyzate was more effective in lowering body lipids and seoritae hydrolyzate had higher antioxidant capacity among soy protein hydrolyzates.
Absorption ; Animals ; Caseins ; Catalase ; Cholesterol ; Diet ; Glutathione Peroxidase ; Humans ; Lipid Metabolism ; Liver ; Male ; Rats ; Soybean Proteins ; Sprains and Strains ; Superoxide Dismutase

Postmenopausal women or ovariectomized rats are associated with increased cholesterol levels, which are risk factors of metabolic syndrome and cardiovascular diseases. Increased prevalence of metabolic syndrome after menopause might be associated with estradiol deficiency. Harmful effect of estradiol hampers the casual usage of hormone to prevent the metabolic syndrome. Soy protein has been reported to show several beneficial effects on health, however it is unclear which components of soy protein is responsible for anti-obesity and hypocholesterolemic effects. Soy isoflavones, genistein and daizein, are suggested to have anti-obesity and hypocholesterolemic effects but with inconsistency. The present study investigated the effect of supplementation of genistein (experiment I) and soy protein containing isoflavones (experiment II) to high fat diet on body weight gain, food intake, liver and fat tissue weight and the lipid levels in ovariectomized rats. Plasma and hepatic lipid contents and the mRNA levels of genes encoding lipid metabolism related proteins, such as CPT1 and HMGR were measured. Ovariectomy increased body weight, fat tissue weight and plasma and hepatic lipid levels which increase the risk of metabolic syndrome. Soy protein could improve plasma and hepatic lipids levels. Soy protein also increased hepatic CPT1 and HMGR mRNA levels. Plasma and hepatic lipids levels could not be decreased by dietary genistein alone. In contrast, lipids levels could be decreased by isoflavone-fortified soy protein, suggesting that the ingestion of soy protein enriched with isoflavone gives more benefit for protecting postmenopausal women from metabolic syndrome.
Animals ; Body Weight ; Cardiovascular Diseases ; Cholesterol ; Diet, High-Fat ; Eating ; Estradiol ; Female ; Genistein* ; Humans ; Isoflavones ; Lipid Metabolism ; Liver ; Menopause ; Metabolism* ; Ovariectomy ; Plasma ; Prevalence ; Rats* ; Risk Factors ; RNA, Messenger ; Soybean Proteins*

This study was aimed to evaluate the prevalence of soy protein hypersensitivity in cow's milk protein-sensitive children in Korea. A total of 1,363 patients with atopic dermatitis, urticaria, enterocolitis syndrome, bronchial asthma or allergic rhinitis were recruited. First, we estimated the prevalence of sensitization to soy in children sensitized to cow's milk. Specific IgE levels > 0.7 kU/L by CAP assay were considered positive. Next, the prevalence of soy allergy in cow's milk allergy (CMA) patients was investigated. Those children whose parents agreed to participate the open challenge test with soy had a convincing history of allergic reactions elicited by cow's milk and these symptoms were relieved by elimination. All of them had negative soy-specific IgE. Patients with positive soy-specific IgE accounted for 18.3% of 224 children sensitized to cow's milk protein. The prevalence of sensitization to soy decreased with age (36.8% in the first year of life, 16.4% in the second year, and 13.7% in the third year). Of 21 CMA patients, 42.9% (n=9) were determined to have soy allergy (mean age 10.3 months). Our results suggest that soy protein formula should be carefully used as a substitute for cow's milk in CMA patients, especially during infancy.
Adolescent ; Age Factors ; Allergens ; Asthma/immunology ; Child ; Child, Preschool ; Dermatitis, Atopic/immunology ; Enterocolitis/immunology ; Female ; Food Hypersensitivity/*epidemiology/immunology ; Human ; Hypersensitivity ; Immunoglobulin E/blood/metabolism ; Infant ; Korea ; Male ; Milk Hypersensitivity/*epidemiology/immunology ; Prevalence ; Rhinitis/immunology ; Soybean Proteins/*chemistry ; Urticaria/immunology