Peptides derived from fermented soybean meal suppresses intestinal inflammation and enhances epithelial barrier function in piglets

Effect of Fermented Soybean (FSB) Supplementation on Gastroesophageal Reflux Disease (GERD)

Gastroesophageal reflux disease (GERD) is a prevalent chronic condition affecting the well-being of both adults and children in general medical practice. Research on the effects of fermented soybean (SB) supplementation in managing GERD is relatively new, with limited studies available. The existing research often lacks sufficient dosing regimens and study durations to differentiate between transient placebo effects and sustained benefits. In this study, the beneficial effects of FSB supplementation were investigated in 110 voluntary participants (NCT06524271). The participants were required to take 1 g of FSB supplement once daily for 12 weeks. GERD symptoms were evaluated using the Reflux Disease Questionnaire (RDQ), while inflammatory markers, including interleukin-4 (IL-4), interleukin-6 (IL-6), and interleukin-8 (IL-8), were measured to assess inflammation. The Quality of Life in Reflux and Dyspepsia (QOLRAD) questionnaire was used to evaluate participants' quality of life. The results indicated that FSB supplementation significantly (p < 0.05) alleviated heartburn and regurgitation symptoms and reduced levels of IL-4, IL-6, and IL-8, indicating a notable anti-inflammatory effect. Additionally, significant (p < 0.05) improvements were observed in QOLRAD scores, particularly in vitality, emotional distress, and physical/social functioning. Collectively, our findings support the use of FSB as an adjuvant approach in managing GERD, with notable improvements in patients' quality of life.

Opportunities and Challenges of Soy Proteins with Different Processing Applications

Soybean meal (SBM) is a prevailing plant protein supplement in animal diets because of its nutritional value and availability. This review paper explores the significance of SBM and processed soy products, emphasizing their nutritional and bioactive components, such as isoflavones and soyasaponins. These compounds are known for their antioxidant and anti-inflammatory properties and are associated with a reduced prevalence of chronic diseases. However, the presence of antinutritional compounds in SBM presents a significant challenge. The paper evaluates various processing methods, including ethanol/acid wash, enzyme treatment, and fermentation, which are aimed at enhancing the nutritional value of soy products. It highlights the significance to maintain a balance between nutritional enhancement and the preservation of beneficial bioactive compounds, emphasizing the importance of different processing techniques to fully exploit the health benefits of soy-based products. Therefore, this review illuminates the complex balance between nutritional improvement, bioactive compound preservation, and the overall health implications of soy products.

Mechanism of action, benefits, and research gap in fermented soybean meal utilization as a high-quality protein source for livestock and poultry

Animal nutritionists have incessantly worked towards providing livestock with high-quality plant protein feed resources. Soybean meal (SBM) has been an essential and predominantly adopted vegetable protein source in livestock feeding for a long time; however, several SBM antinutrients could potentially impair the animal's performance and growth, limiting its use. Several processing methods have been employed to remove SBM antinutrients, including fermentation with fungal or bacterial microorganisms. According to the literature, fermentation, a traditional food processing method, could improve SBM's nutritional and functional properties, making it more suitable and beneficial to livestock. The current interest in health-promoting functional feed, which can enhance the growth of animals, improve their immune system, and promote physiological benefits more than conventional feed, coupled with the ban on the use of antimicrobial growth promoters, has caused a renewed interest in the use of fermented SBM (FSBM) in livestock diets. This review details the mechanism of SBM fermentation and its impacts on animal health and discusses the recent trend in the application and emerging advantages to livestock while shedding light on the research gap that needs to be critically addressed in future studies. FSBM appears to be a multifunctional high-quality plant protein source for animals. Besides removing soybean antinutrients, beneficial bioactive peptides and digestive enzymes are produced during fermentation, providing probiotics, antioxidants, and immunomodulatory effects. Critical aspects regarding FSBM feeding to animals remain uncharted, such as the duration of fermentation, the influence of feeding on digestive tissue development, choice of microbial strain, and possible environmental impact.

Recent advances in exploring and exploiting soybean functional peptides-a review

Soybeans are rich in proteins and phytochemicals such as isoflavones and phenolic compounds. It is an excellent source of peptides with numerous biological functions, including anti-inflammatory, anticancer, and antidiabetic activities. Soy bioactive peptides are small building blocks of proteins that are released after fermentation or gastrointestinal digestion as well as by food processing through enzymatic hydrolysis, often in combination with novel food processing techniques (i.e., microwave, ultrasound, and high-pressure homogenization), which are associated with numerous health benefits. Various studies have reported the potential health benefits of soybean-derived functional peptides, which have made them a great substitute for many chemical-based functional elements in foods and pharmaceutical products for a healthy lifestyle. This review provides unprecedented and up-to-date insights into the role of soybean peptides in various diseases and metabolic disorders, ranging from diabetes and hypertension to neurodegenerative disorders and viral infections with mechanisms were discussed. In addition, we discuss all the known techniques, including conventional and emerging approaches, for the prediction of active soybean peptides. Finally, real-life applications of soybean peptides as functional entities in food and pharmaceutical products are discussed.

Structure characterization of soybean peptides and their protective activity against intestinal inflammation

Soybean peptides serve as functional foods with impressive health benefits. The structure characteristics of peptides are highly related to the health benefits. The structure-activity relationship and mechanism underlined are important scientific questions in this field. To answer these questions, soybean peptides were produced by combinatory enzymatic hydrolysis in this work. Fifty-two peptide sequences were identified by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The anti-inflammatory activities of these peptides were investigated by using a lipopolysaccharide (LPS)-induced inflammation cell model. Soybean peptides could significantly promote cell proliferation. Additionally, soybean peptides could alleviate LPS-induced inflammation by reducing the production and expression of nitric oxide (NO), tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6). Moreover, soybean peptides could promote the mRNA expression of proteins related to inflammation inhibition (IL-10) and tight junction modulation. The structure-activity relationship was addressed. The results documented the potential of soybean peptides as functional foods.

Porcine and Chicken Intestinal Epithelial Cell Models for Screening Phytogenic Feed Additives—Chances and Limitations in Use as Alternatives to Feeding Trials

Numerous bioactive plant additives have shown various positive effects in pigs and chickens. The demand for feed additives of natural origin has increased rapidly in recent years to support the health of farm animals and thus minimize the need for antibiotics and other drugs. Although only in vivo experiments can fully represent their effect on the organism, the establishment of reliable in vitro methods is becoming increasingly important in the goal of reducing the use of animals in experiments. The use of cell models requires strict control of the experimental conditions so that reliability and reproducibility can be achieved. In particular, the intestinal porcine epithelial cell line IPEC-J2 represents a promising model for the development of new additives. It offers the possibility to investigate antioxidative, antimicrobial, anti- or pro-proliferative and antiviral effects. However, the use of IPEC-J2 is limited due to its purely epithelial origin and some differences in its morphology and functionality compared to the in vivo situation. With regard to chickens, the development of a reliable intestinal epithelial cell model has attracted the attention of researchers in recent years. Although a promising model was presented lately, further studies are needed to enable the standardized use of a chicken cell line for testing phytogenic feed additives. Finally, co-cultivation of the currently available cell lines with other cell lines and the development of organoids will open up further application possibilities. Special emphasis was given to the IPEC-J2 cell model. Therefore, all publications that investigated plant derived compounds in this cell line were considered. The section on chicken cell lines is based on publications describing the development of chicken intestinal epithelial cell models.

Current perspectives on the anti-inflammatory potential of fermented soy foods

Fermented soy foods (FSF) are gaining significant attention due to promising health benefits. In recent years, FSF are being studied extensively due to the presence of diverse functional ingredients including active isoflavones and peptides along with essential micronutrients. The process of fermentation is responsible for the enrichment of various bioactive principles in soy-based fermented foods and exclusion of some anti-nutrient factors which are found predominantly in raw soybeans. Emerging evidence suggests that FSF possess immense therapeutic potential against inflammation and associated pathological complications. Extracts prepared from various FSF (e.g. fermented soy paste, milk, and sauce) were found to exert promising anti-inflammatory effects in numerous in vitro and in vivo settings. Moreover, clinical findings highlighted an inverse relationship between consumption of FSF and the prevalence of chronic inflammatory disorders among the communities which habitually consume fermented soy products. Molecular mechanisms underlying the anti-inflammatory role of FSF have been delineated in many literatures which collectively suggest that FSF extracts have regulatory actions over the expression and/or activity of several proinflammatory cytokines, inflammatory mediators, oxidative stress markers, and some other factors involved in the inflammatory pathways. The present review discusses the anti-inflammatory effects of FSF with mechanistic insights based upon the available findings from cell culture, preclinical, and clinical investigations.

Soymilk-fermented with Lactobacillus delbrueckii subsp. delbrueckii TUA4408L improves immune-health in pigs

Lactobacillus delbrueckii subsp. delbrueckii TUA4408L has the ability to grow and ferment soymilk and is able to modulate the innate immune response of intestinal epithelial cells in vitro. These two properties prompt us to evaluate whether the soymilk fermented with the TUA4408L strain can induce beneficial immunomodulatory effects in vivo. For this purpose, pigs were selected as a preclinical model. The studies performed here demonstrated that the L. delbrueckii subsp. delbrueckii TUA4408L-fermented soymilk (TUA4408L FSM) reduced blood markers of inflammation and differentially regulated the expression of inflammatory and regulatory cytokines in the intestinal mucosa. These immunological changes induced by the TUA4408L FSM were associated to an enhanced resistance to pathogenic Escherichia coli and an improved grow performance and meat quality of pigs. The experiments and analysis in our study indicate that the immunobiotic TUA4408L FSM could be an interesting non-dairy functional food to beneficially modulate the intestinal immune system, improve protection against pathogens and reduce inflammatory damage. The preclinical study carried out here in pigs could have a better correlation in humans, compared to a rodent model. However, the clinical relevance of these findings still needs to be confirmed by further research, for example, in controlled human challenge studies.

Antidiabetic potential of soy protein/peptide: A therapeutic insight

Soybean (Glycine max) harbours high quality proteins which have been evident to exhibit therapeutic properties in alleviating many diseases including but not limited to diabetes and its related metabolic complications. Since diabetes is often manifested with hyperglycemia, impaired energy homeostasis and even low-grade chronic inflammation, plenty of information has raised the suggestion for soy protein supplementation in preventing and controlling these abnormalities. Moreover, clinical intervention studies have established a noteworthy correlation between soy protein intake and lower prevalence of diabetes. Besides soy protein, various soy-derived peptides also have been found to trigger antidiabetic response in different in vitro and in vivo models. Molecular mechanisms underlying the antidiabetic actions of soy protein and peptide have been predicted in many literatures. Results demonstrate that components of soy protein can act in diversified ways and modulate various cell signaling pathways to bring energy homeostasis and to regulate inflammatory parameters associated with diabetic pathophysiology. The main objective of the present review lies in a systemic understanding of antidiabetic role of soy protein and peptide in the context of impaired glucose and lipid metabolism, and inflammation.

Protective Effects of Shrimp Peptide on Dextran Sulfate Sodium-Induced Colitis in Mice

Inflammatory bowel disease, an intestinal relapsing inflammatory disease, not only impairs gastrointestinal function but also increases the chances of developing colon cancer. Currently, the effects of shrimp peptide (SP) in mice model of ulcerative colitis (UC) are still unclear. In particular, it is uncertain whether SP affects the gut flora with UC mice. In this study, we investigated the anti-inflammatory effects of SP on a dextran sulfate sodium (DSS)-induced mouse model of UC. Firstly, the molecular weight of SP was mainly distributed in the range of 180-1,000 Da (61.95% proportion), and the amino acid composition showed that SP contained 17 amino acids, of which, the essential amino acids accounted for 54.50%. In vivo, oral SP significantly attenuated the severity of colitis, such as diarrhea, weight loss, and rectal bleeding. Furthermore, treatment with SP remarkably ameliorated intestinal barrier integrity, thus lowering the levels of the inflammatory cytokines and ameliorating antioxidant indices and intestinal injury indicators in the serum and colon. Lastly, the cecal contents were used to sequence and analyze the 16S rRNA genes of bacteria. Results suggested that treatment with SP could restore the balance of intestinal flora in modeled mice by regulating the abundance of pathogenic and beneficial bacteria. Furthermore, SP could significantly improve intestinal flora dysfunction in mice with UC. In summary, our findings show that SP has a prophylactic and therapeutic effect in UC in vivo, thereby highlighting its broad medicinal applications.

Antimicrobial Peptides in Gut Health: A Review

Animal antimicrobial peptides (AMPs), known as broad-spectrum and high-efficiency antibacterial activity, are important effector molecules in innate immune system. AMPs not only have antimicrobial, antiviral and antitumor effects but also exhibit important effects in vivo, such as anti-inflammatory response, recruiting immune cells, promoting epithelial damage repair, and promoting phagocytosis of bacteria. However, research on the application of AMPs is incomplete and controversial. This review mainly introduces the classification of AMPs, biological functions, as well as the mechanisms of action, expression rules, and nutrition regulation from three perspectives, aiming to provide important information for the application of AMPs.

Assessment of Intestinal Immunity and Permeability of Broilers on Partial Replacement Diets of Two-Stage Fermented Soybean Meal by Bacillus velezensis and Lactobacillus brevis ATCC 367

The effect of soybean peptides from fermented soybean meal on the intestinal immunity and tight junction of broilers was assessed. Roughly, two-stage fermented soybean meal prepared with Bv and Lb (FSBM_B+L), which has nearly three times higher soluble peptides than soybean meal (SBM), and reduced galacto-oligosaccharide (GOS) content and allergen protein. The one-stage fermented by Bv (FSBM_B) has the highest soluble peptides, while commercial lactic acid bacteria (FSBM_L) has the highest Lactic acid bacteria count; these were used to compare the differences in the process. Ross308 broilers (n = 320) were divided into four groups: SBM diet and a diet replaced with 6% FSBM_B+L, FSBM_B, or FSBM_L. The growth performance was recorded during the experiment, and six birds (35-day-old) per group were euthanized. Analysis of their jejunum and ileum showed that the fermented soybean meal significantly improved the villus height in the jejunum (p < 0.05) and reduced the crypt hyperplasia. The FSBM_B group had the highest reducing crypt depth; however, the FSBM_B+L group had the highest villus height/crypt depth in the ileum (p < 0.05). In the jejunum, the relative mRNA of CLDN-1 and Occludin increased 2-fold in the treatments, and ZO-1 mRNA increased 1.5 times in FSBM_L and FSBM_B+L (p < 0.05). Furthermore, the level of NF-κB and IL-6 mRNAs in FSBM_L increased, respectively, by 4 and 2.5 times. While FSBM_B, along with FSBM_B+L, had a 1.5-fold increase in the mRNA of IL-10, that of NF-κB increased 2-fold. FSBM_B+L and FSBM_B singly led to a 2- and 3-fold increase in IL-6 mRNA, respectively (p < 0.05). FSBM_B and FSBM_B+L can also upregulate MUC2 in the jejunum (p < 0.05). In short, using the soybean peptides from two-stage fermented soybean meal can ameliorate the negative factors of SBM and effectively regulate immune expression and intestinal repair, which will help broilers maintain intestinal integrity.

Performance, Serum Biochemical and Immunological Parameters, and Digestive Enzyme and Intestinal Barrier-Related Gene Expression of Broiler Chickens Fed Fermented Fava Bean By-Products as a Substitute for Conventional Feed

Improving the nutritional quality of unconventional feed ingredients such as fava bean by-products can enhance their utilization by broiler chickens. Hence, the quality of fermented fava bean by-products (FFB), in addition to growth, nutrient digestibility, digestive enzyme, and intestinal barrier-related gene expression, and serum biochemical and immunological parameters were evaluated in response to different levels of FFB. A total of 500 1-day-old broiler chicks (46.00 ± 0.388 g) were allocated to five groups with 10 replicates each (100 chicks per treatment). The first group was fed a corn-soybean diet (control diet), and the other four groups were fed a diet containing 5, 15, 25, and 35% FFB for 38 days. Birds fed 25% FFB exhibited maximum body weight gain (increase by 12.5%, compared with the control group) and the most improved feed conversion ratio. Additionally, birds fed FFB at 15, 25, and 35% showed improved dry matter and crude protein digestibility. Moreover, birds fed FFB at 25 and 35% exhibited a decrease in ileal pH and an increase in fiber digestibility (p < 0.05). Upregulation of digestive enzyme genes (AMY2A, PNLIP, and CCK) was observed in groups fed with FFB. The most prominent upregulation of genes encoding tight junction proteins (claudin-1, occludin, and junctional adhesion molecules) in the duodenum was observed in chicks fed 25 and 35% FFB (increase of 0.66-, 0.31-, and 1.06-fold and 0.74-, 0.44-, and 0.92-fold, respectively). Additionally, the highest expression level of enterocyte protective genes [glucagon-like peptide (GLP-2), mucin-2 (MUC-2), and fatty acid-binding protein (FABP-6)] was detected in duodenum of chicks fed high levels of FFB. Substitution of corn-soybean diet with FFB had an inhibitory effect on cecal pathogenic microbes (Escherichia coli and Clostridium perfringens) and increased beneficial microflora (Lactobacilli and Bifidobacterium), especially at high levels. Additionally, an increase was observed in IgM and lysozyme activity, with no effect on IgA in all groups fed FFB. All levels of FFB decreased cholesterol levels. Based on our results, we concluded that substitution of corn-soybean diet with FFB can improve the growth rate and nutrient digestibility of broiler chickens, enhance their intestinal barrier functions, and increase the number of beneficial microorganisms. Using FFB at 25% had a positive effect on the growth performance of broiler chickens, and it could be utilized in poultry farms.

Roles of Dietary Bioactive Peptides in Redox Balance and Metabolic Disorders

Bioactive peptides (BPs) are fragments of 2-15 amino acid residues with biological properties. Dietary BPs derived from milk, egg, fish, soybean, corn, rice, quinoa, wheat, oat, potato, common bean, spirulina, and mussel are reported to possess beneficial effects on redox balance and metabolic disorders (obesity, diabetes, hypertension, and inflammatory bowel diseases (IBD)). Peptide length, sequence, and composition significantly affected the bioactive properties of dietary BPs. Numerous studies have demonstrated that various dietary protein-derived BPs exhibited biological activities through the modulation of various molecular mechanisms and signaling pathways, including Kelch-like ECH-associated protein 1/nuclear factor erythroid 2-related factor 2/antioxidant response element in oxidative stress; peroxisome proliferator-activated-γ, CCAAT/enhancer-binding protein-α, and sterol regulatory element binding protein 1 in obesity; insulin receptor substrate-1/phosphatidylinositol 3-kinase/protein kinase B and AMP-activated protein kinase in diabetes; angiotensin-converting enzyme inhibition in hypertension; and mitogen-activated protein kinase and nuclear factor-kappa B in IBD. This review focuses on the action of molecular mechanisms of dietary BPs and provides novel insights in the maintenance of redox balance and metabolic diseases of human.

Tolerogenic Effect Elicited by Protein Fraction Derived From Different Formulas for Dietary Treatment of Cow's Milk Allergy in Human Cells

Several formulas are available for the dietary treatment of cow’s milk allergy (CMA). Clinical data suggest potentially different effect on immune tolerance elicited by these formulas. We aimed to comparatively evaluate the tolerogenic effect elicited by the protein fraction of different formulas available for the dietary treatment of CMA. Five formulas were compared: extensively hydrolyzed whey formula (EHWF), extensively hydrolyzed casein formula (EHCF), hydrolyzed rice formula (HRF), soy formula (SF), and amino acid-based formula (AAF). The formulas were reconstituted in water according to the manufacturer’s instructions and subjected to an in vitro infant gut simulated digestion using a sequential gastric and duodenal static model. Protein fraction was then purified and used for the experiments on non-immune and immune components of tolerance network in human enterocytes and in peripheral mononuclear blood cells (PBMCs). We assessed epithelial layer permeability and tight junction proteins (occludin and zonula occludens-1, ZO-1), mucin 5AC, IL-33, and thymic stromal lymphopoietin (TSLP) in human enterocytes. In addition, Th1/Th2 cytokine response and Tregs activation were investigated in PBMCs from IgE-mediated CMA infants. EHCF-derived protein fraction positively modulated the expression of gut barrier components (mucin 5AC, occludin and ZO-1) in human enterocytes, while SF was able to stimulate the expression of occludin only. EHWF and HRF protein fractions elicited a significant increase in TSLP production, while IL-33 release was significantly increased by HRF and SF protein fractions in human enterocytes. Only EHCF-derived protein fraction elicited an increase of the tolerogenic cytokines production (IL-10, IFN-γ) and of activated CD4+FoxP3+ Treg number, through NFAT, AP1, and Nf-Kb1 pathway. The effect paralleled with an up-regulation of FoxP3 demethylation rate. Protein fraction from all the study formulas was unable to induce Th2 cytokines production. The results suggest a different regulatory action on tolerogenic mechanisms elicited by protein fraction from different formulas commonly used for CMA management. EHCF-derived protein fraction was able to elicit tolerogenic effect through at least in part an epigenetic modulation of FoxP3 gene. These results could explain the different clinical effects observed on immune tolerance acquisition in CMA patients and on allergy prevention in children at risk for atopy observed using EHCF.

Glycation sites and bioactivity of lactose-glycated caseinate hydrolysate in lipopolysaccharide-injured IEC-6 cells

During the thermal processing of milk, Maillard reactions occur between proteins and lactose to generate glycated proteins. In this study, a lactose-glycated caseinate was hydrolyzed by trypsin. The obtained glycated caseinate (GCN) hydrolysate had a lactose content of 10.8 g/kg of protein. We identified its glycation sites and then assessed it for its protective effect against lipopolysaccharide-induced barrier injury using a rat intestinal epithelial cell line (IEC-6 cells) as a cell model and unglycated caseinate (CN) hydrolysate as a reference. Results from our liquid chromatography-mass spectrometry analysis of the GCN hydrolysate verified that lactose glycation occurred at the Lys residues in 3 casein components (α_S1-casein, β-casein, and κ-casein), and this resulted in the formation of 5 peptides with the following amino acid sequences: EMPFPKYPKYPVEPF, HIQKEDVPSE, GSENSEKTTMPL, NQDKTEIPT, and EGIHAQQKEPM. The results from cell experiments showed that the 2 hydrolysates could promote cell growth and decrease lactate dehydrogenase release in the lipopolysaccharide-injured cells; more importantly, they could partially protect the damaged barrier function of the cells by increasing trans-epithelial electrical resistance, decreasing epithelial permeability, and upregulating the expression of the 3 tight junction proteins zonula occludens-1, occludin, and claudin-1. However, compared with CN hydrolysate, GCN hydrolysate showed lower efficacy in protecting against cellular barrier dysfunction. We propose that the different chemical characteristics of the CN hydrolysate and the GCN hydrolysate (i.e., amino acid loss and lactose conjugation) contributed to the lower barrier-protective efficacy of the GCN hydrolysate. During dairy processing, protein glycation of the Maillard type might have a non-negligible, unfavorable effect on dairy proteins, in view of the resulting protein glycation we found and the critical function of proteins for maintaining the integrity of the intestinal barrier.

Isolation of a Highly Efficient Antigenic-Protein-Degrading Bacillus amyloliquefaciens and Assessment of Its Safety

Simple Summary

Soybean meal (SBM), a byproduct of soybean oil extraction, is a commonly used dietary protein in the poultry and swine feed industries because of its high quality protein and relatively well-balanced amino acids. However, major antigenic proteins in SBM, glycinin and β-conglycinin, can trigger allergic reactions, including intestine villus atrophy and other malabsorption syndromes, in newborn animals. Microbial fermentation is considered an economically viable processing technique to reduce the content of antigenic proteins, and improve the nutritional quality of SBM. The kind of microorganism used in fermentation is one of the major factors affecting the nutritional value of SBM. In this study, a highly efficient Bacillus. amyloliquefaciens strain was successfully isolated with convenient and effective plate tests, and used in a fermentation experiment. Fermentation with B. amyloliquefaciens for 24 h effectively degraded the glycinin and β-conglycinin in SBM, significantly improved the crude protein content and acid soluble protein concentration, and increased the total amino acid content. Furthermore, B. amyloliquefaciens had no adverse effects on animal health. These results indicate that the B. amyloliquefaciens strain isolated in this study is safe for animal use and can be widely used in SBM fermentation.

Abstract

The aims of this study were to screen and isolate a highly efficient strain from the rumen of a cow that can degrade the antigenic soy proteins in soybean meal (SBM) and improve the nutritional value of SBM by fermenting it with this strain. The safety of this strain was investigated with an acute oral toxicity test. A Bacillus amyloliquefaciens strain was successfully screened with plate tests and fermentation. After solid state fermentation of SBM with B. amyloliquefaciens for 24 h, the amounts of glycinin and β-conglycinin, two major antigenic proteins in SBM, decreased by 92.32% and 85.05%, respectively. The crude protein content in the fermented soybean meal (FSBM) increased by 17.54% compared with that in SBM. Notably, the trichloroacetic-acid-soluble protein (TCA-SP) content, particularly small peptides and free amino acids, was 9.97-fold higher in FSBM than in SBM. The in vitro dry matter digestibility and digestible energy of SBM increased from 62.91% to 72.52% and from 10.42 MJ/kg to 13.37 MJ/kg (dry matter basis), respectively, after fermentation. The acute oral toxicity test suggested that the strain exerted no harmful effects on the relative organ weights, the morphological tissue structure, or the health of mice. These results indicate that the B. amyloliquefaciens strain isolated in this study is a safe strain for animals, and could be used to improve the nutritional quality of SBM by solid-state fermentation.

Effects of Fermented Soybean Meal Supplementation on the Growth Performance and Cecal Microbiota Community of Broiler Chickens

Simple Summary

Microbial fermentation is considered an economically viable processing technique to reduce the content of anti-nutritional factors and improve the nutritional quality of soybean meal (SBM). Fermented soybean meal (FSBM) exerts beneficial effects on the growth performance, carcass traits, and meat quality of broilers. However, there is very little information on the effects of FSBM on cecal microbial composition and diversity in broilers. Hence, this trial is conducted to investigate the effects of the partial replacement of SBM with FSBM in the diet on growth performance and cecal microflora of broilers. Replacing 25% of the SBM in the diet of broilers with FSBM promoted average daily gain and feed conversion ratio during the growth and whole phases. Both dietary treatment (25% or 50% of the SBM in the basal diet was replaced with FSBM) influenced the serum immunity, diversity and composition of cecal microbiota in broilers. FSBM supplementation in the diet shifted the cecal microbial community of broilers towards a healthier balance by increasing the abundance of beneficial bacteria and reducing the abundance of potentially harmful bacteria.

Abstract

This study investigated the growth performance, serum immunity, and cecal bacterial microbiota of broilers fed a diet in which soybean meal (SBM) was partially replaced with fermented soybean meal (FSBM) for 36 days. A total of 180 one-day-old male Cobb 500 broilers were randomly divided into three dietary groups (six replicates per group): corn-SBM diet (CC); 25% SBM replaced by FSBM (SC); 50% SBM replaced by FSBM (TC). The average daily gain (ADG) and feed conversion rates (FCR) were higher in SC than CC and TC groups (p < 0.05) during the growth (d 22–36) and whole (d 1–36) phases. No significant difference was observed in ADG and average daily feed intake (ADFI) between CC and TC groups during any phases. Dietary treatments increased serum IgA, IgG, and IgM, Chao 1, observed species, and the abundance of the phylum Fimicutes but decreased the proportion of Proteobacteria (p < 0.05). Dietary treatments increased the abundance of the genera Lachnospiraceae, Lachnoclostridium, Gastranaerophilales, and Lactobacillus but decreased the abundance of Escherichia-Shigella and Clostridiales (p < 0.05). Spearman’s correlations showed that the abundance of Gastranaerophilales was positively correlated with ADG and serum immunity, and the abundance of Lactobacillus was strongly positively with IgM. Thus, replacing 25% of SBM with FSBM improves the growth performance and serum immunity of broilers, possibly due to altered cecal microbial composition.