Modulation of Gut Microbiota by Soybean 7S Globulin Peptide That Involved Lipopolysaccharide-Peptide Interaction

Interplay of Food-Derived Bioactive Peptides with Gut Microbiota: Implications for Health and Disease Management

Bioactive peptides (BPs) are protein fragments with beneficial effects on metabolism, physiology, and diseases. This review focuses on proteolytic BPs, which are produced by the action of gut microbiota on proteins in food and have demonstrated to influence the composition of gut microbes. And gut microbiota are candidate targets of BPs to alleviate oxidative stress, enhance immunity, and control diseases, including diabetes, hypertension, obesity, cancer, and immune and neurodegenerative diseases. Despite promising results, further research is needed to understand the mechanisms underlying the interactions between BPs and gut microbes, and to identify and screen more BPs for industrial applications. Overall, BPs offer potential as therapeutic agents for various diseases through their interactions with gut microbes, highlighting the importance of continued research in this area.

Effect of Bioactive Peptides on Gut Microbiota and Their Relations to Human Health

Bioactive peptides derived from both exogenous and endogenous origins have been studied extensively to use their beneficial effects in humans and animals. Bioactive peptides exhibit beneficial bodily functions and contribute to a healthy gastrointestinal system by influencing barrier functions, immune responses, and gut microbiota. Gut microbiota is a diverse microbial community that significantly influences the overall well-being and homeostasis of the body. Factors such as diet, age, lifestyle, medication, and environmental circumstances can affect the composition and diversity of the gut microbiota. The disturbances or imbalances in the gut microbiota have been associated with various health problems. The interplays between bioactive peptides and gut microbiota are not fully understood, but bioactive peptides hold promise as modulators of the gut microbiota to promote gut health. Almost all the bioactive research on human health, including the development of therapeutics and nutritional interventions, uses cell culture, even though their direct biofunctional activities can only occur when absorbed in the intestine and into the blood system. This review focuses on the current understanding of bioactive peptides in gut microbiota and their impact and mechanisms on gut and human health. The novelty of this review lies in its comprehensive analysis of the multifaceted interactions between bioactive peptides and gut microbiota, integrating knowledge from diverse disciplines between microbiology and nutrition. By elucidating the underlying mechanisms and identifying current research gaps, this review offers an outlook on the potential of bioactive peptides in promoting gut health and shaping future therapeutic and nutritional interventions.

miRNA Expression Analysis of IPEC-J2 Cells Damaged by Soybean 7S Globulin Reveals ssc-miR-221-5p as the Factor Alleviating Cell Damage

The most significant and sensitive antigen protein that causes diarrhea in weaned pigs is soybean 7S globulin. Therefore, identifying the primary target for minimizing intestinal damage brought on by soybean 7S globulin is crucial. MicroRNA (miRNA) is closely related to intestinal epithelium's homeostasis and integrity. However, the change of miRNAs' expression and the function of miRNAs in Soybean 7S globulin injured-IPEC-J2 cells are still unclear. In this study, the miRNAs' expression profile in soybean 7S globulin-treated IPEC-J2 cells was investigated. Fifteen miRNAs were expressed differently. The differentially expressed miRNA target genes are mainly concentrated in signal release, cell connectivity, transcriptional inhibition, and Hedgehog signaling pathway. Notably, we noticed that the most significantly decreased miRNA was ssc-miR-221-5p after soybean 7S globulin treatment. Therefore, we conducted a preliminary study on the mechanisms of ssc-miR-221-5p in soybean 7S globulin-injured IPEC-J2 cells. Our research indicated that ssc-miR-221-5p may inhibit ROS production to alleviate soybean 7S globulin-induced apoptosis and inflammation in IPEC-J2 cells, thus protecting the cellular mechanical barrier, increasing cell proliferation, and improving cell viability. This study provides a theoretical basis for the prevention and control of diarrhea of weaned piglets.

Condensation of Soy Protein Peptides Contributes to Sequester Bile Acids and Mitigate LPS-Induced Inflammation

Soy protein is widely known to have serum triglyceride (TG) and cholesterol-lowering effects associated with a reduced risk of cardiovascular disease. Recent studies highlighted that the extension region (ER) domain of soy 7S globulin (β-conglycinin) is a key component responsible for the serum TG-lowering effect via modulation of bile acid (BA) homeostasis. Here, we studied the sequestration of BAs by ER peptides during intestinal digestion in vitro and assessed the anti-inflammatory effects of ER peptides using Caco-2/HT29-MTX/RAW264.7 triple-cell cocultures as an intestine cell model. Results show that ER peptides, which share characteristics of intrinsically disordered regions (IDRs), are capable of forming peptide condensates and exhibit the capability to sequester BA-containing colloidal structures during intestinal digestion in vitro. Moreover, BAs enhance the penetration of peptide condensates within the mucus layer, enabling ER peptides to mitigate lipopolysaccharide (LPS)-induced gut inflammation. These results provide a possible explanation for the molecular mechanisms underlying the modulation of BA homeostasis by soybean proteins.

Extension Region Domain of Soybean 7S Globulin Contributes to Serum Triglyceride-Lowering Effect via Modulation of Bile Acids Homeostasis

SCOPE

Soybean 7S globulin (β-conglycinin), a major soybean storage protein, has been demonstrated to exert remarkable triglyceride (TG) and cholesterol-lowering effects, yet the underlying mechanism remains controversial.

METHODS AND RESULTS

A comparative investigation is performed to assess the contribution of different structural domains of soybean 7S globulin, including core region (CR) and extension region (ER) domains, to biological effects of soybean 7S globulin using a high-fat diet rat model. The results show that ER domain mainly contributes to the serum TG-lowering effect of soybean 7S globulin, but not for CR domain. Metabolomics analysis reveals that oral administration of ER peptides obviously influences the metabolic profiling of serum bile acids (BAs), as well as significantly increased the fecal excretion of total BAs. Meanwhile, ER peptides supplementation reshapes the composition of gut microbiota and impacts the gut microbiota-dependent biotransformation of BAs which indicate by a significantly increased secondary BAs concentration in fecal samples. These results highlight that TG-lowering effects of ER peptides mainly stem from their modulation of BAs homeostasis.

CONCLUSION

Oral administration of ER peptides can effectively lower serum TG level by regulating BAs metabolism. ER peptides have potential to be used as a candidate pharmaceutical for the intervention of dyslipidemia.

Microbiology, flavor formation, and bioactivity of fermented soybean curd (furu): A review

Soybeans are an important plant-based food but its beany flavor and anti-nutritional factors limit its consumption. Fermentation is an effective way to improve its flavor and nutrition. Furu is a popular fermented soybean curd and mainly manufactured in Asia, which has been consumed for thousands of years as an appetizer because of its attractive flavors. This review first classifies furu products on the basis of various factors; then, the microorganisms involved in its fermentation and their various functions are discussed. The mechanisms for the formation of aroma and taste compounds during fermentation are also discussed; and the microbial metabolites and their bioactivities are analyzed. Finally, future prospects and challenges are introduced and further research is proposed. This information is needed to protect the regional characteristics of furu and to regulate its consistent quality. The current information suggests that more in vivo experiments and further clinical trials are needed to confirm its safety and the microbial community needs to be optimized and standardized for each type of furu to improve the production process.

Food Peptides, Gut Microbiota Modulation, and Antihypertensive Effects

The gut microbiota is increasingly important in the overall human health and as such, it is a target in the search of novel strategies for the management of metabolic disorders including blood pressure, and cardiovascular diseases. The link between microbiota and hypertension is complex and this review is intended to provide an overview of the mechanism including the production of postbiotics, mitigation of inflammation, and the integration of food biological molecules within this complex system. The focus is on hydrolyzed food proteins and peptides which are less commonly investigated for prebiotic properties. The analysis of available data showed that food peptides are multifunctional and can prevent gut dysbiosis by positively affecting the production of postbiotics or gut metabolites (short-chain fatty acids, polysaccharides, biogenic amines, bile acids). Peptides and the postbiotics then displayed antihypertensive effects via the renin-angiotensin system, the gut barrier, the endothelium, and reduction in inflammation and oxidative stress. Despite the promising antihypertensive effect of the food peptides via the modulation of the gut, there is a lack of human studies as most of the works have been conducted in animal models.

High hydrostatic pressure treatment reduces the potential antigenicity of β-conglycinin by changing the protein structure during in vitro digestion

BACKGROUND

High hydrostatic pressure (HHP) treatment has been used to alleviate the allergenicity of soybeans, but there are little data about the potential antigenicity of β-conglycinin after HHP treatment.

RESULTS

We examined the effects of HHP treatment on the antigenicity and structure of β-conglycinin. When the pressure was 300 and 400 MPa, HHP treatment reduced the immunoglobulin (Ig)G binding capacity of β-conglycinin, while its IgE binding capacity did not change significantly. After in vitro digestion, both the IgE and IgG binding of β-conglycinin was obviously inhibited after HHP treatment at 400 MPa and 60 °C, although its binding capacity with linear epitope antibodies increased. Moreover, HHP treatment changed the secondary structure of β-conglycinin, the content of α-helix and random coils increased, while the β-sheet and β-turn decreased. After HHP treatment, the conformational structure was unfolded so that a large number of hydrophobic regions were exposed.

CONCLUSION

HHP treatment alleviated the potential antigenicity of β-conglycinin by modifying its structure, which facilitated in vitro digestion and destroyed epitopes. This research provides a new insight into the mechanism of HHP treatment that affects the sensitization of soy protein allergens. © 2022 Society of Chemical Industry.

Digestion Resistance of Soybean 7S Protein and Its Implications for Reinforcing the Gastric Mucus Barrier

Previous studies have found that soybean protein, especially soybean 7S protein (β-conglycinin), exhibits digestion resistance, but the mechanism of digestion resistance and its implications for human health are still unclear. Here, we show that the extracted soybean 7S protein contains both oligomer globulins and amyloid aggregates, while the gastric digested soybean 7S protein only contains amyloid aggregates and thus exhibits digestion resistance. An animal experiment shows that un-digestible soybean 7S protein effectively prevents aspirin-induced acute gastric mucosa damage. The impacts of un-digestible soybean 7S protein on gastric mucus barrier properties are investigated using quartz crystal microbalance with dissipation (QCM-D), Langmuir monolayer, and multiple particle tracking (MPT). Results show that these un-digestible protein aggregates can penetrate into gastric mucus, increase the viscosity and compactness of the mucin layer, and reinforce the gastric mucus barrier properties. The findings are helpful to understand that high consumption of non-fermented soybean foods is associated with a decreased risk of gastric cancer.

The Functional Interplay between Gut Microbiota, Protein Hydrolysates/Bioactive Peptides, and Obesity: A Critical Review on the Study Advances

Diet is an essential factor determining the ratio of pathogenic and beneficial gut microbiota. Hydrolysates and bioactive peptides have been described as crucial ingredients from food protein that potentially impact human health beyond their roles as nutrients. These compounds can exert benefits in the body, including modulation of the gut microbiota, and thus, they can reduce metabolic disorders. This review summarized studies on the interaction between hydrolysates/peptides, gut microbes, and obesity, focusing on how hydrolysates/peptides influence gut microbiota composition and function that improve body weight. Findings revealed that gut microbes could exert anti-obesity effects by controlling the host’s energy balance and food intake. They also exhibit activity against obesity-induced inflammation by changing the expression of inflammatory-related transcription factors. Protein hydrolysates/peptides can suppress the growth of pro-obesity gut bacteria but facilitate the proliferation of those with anti-obesity effects. The compounds provide growth factors to the beneficial gut bacteria and also improve their resistance against extreme pH. Hydrolysates/peptides are good candidates to target obesity and obesity-related complications. Thus, they can allow the development of novel strategies to fight incidences of obesity. Future studies are needed to understand absorption fate, utilization by gut microbes, and stability of hydrolysates/peptides in the gut under obesity.

Bioactive components of mushrooms: Processing effects and health benefits

Mushrooms have been recognized for their culinary attributes for long and were relished in the most influential civilizations in history. Currently, they are the focus of renewed research because of their therapeutic abilities. Nutritional benefits from mushrooms are in the form of a significant source of essential proteins, dietary non-digestible carbohydrates, unsaturated fats, minerals, as well as various vitamins, which have enhanced its consumption, and also resulted in the development of various processed mushroom products. Mushrooms are also a crucial ingredient in traditional medicine for their healing potential and curative properties. The literature on the nutritional, nutraceutical, and therapeutic potential of mushrooms, and their use as functional foods for the maintenance of health was reviewed, and the available literature indicates the enormous potential of the bioactive compounds present in mushrooms. Future research should be focused on the development of processes to retain the mushroom bioactive components, and valorization of waste generated during processing. Further, the mechanisms of action of mushroom bioactive components should be studied in detail to delineate their diverse roles and functions in the prevention and treatment of several diseases.

Impact of food-derived bioactive peptides on gut function and health

The gastrointestinal tract (GIT) is the largest interface between our body and the environment. It is an organ system extending from the mouth to the anus and functions for food intake, digestion, transport and absorption of nutrients, meanwhile providing protection from environmental factors, like toxins, antigens, and pathogens. Diet is one of the leading factors modulating the function of the GIT. Bioactive peptides presenting naturally in food or derived from food proteins during digestion or processing have been revealed multifunctional in diverse biological processes, including maintaining gut health and function. This review summarizes the available evidence regarding the effects of food-derived bioactive peptides on gut function and health. Findings and insights from studies based on in vitro and animal models are discussed. The gastrointestinal mucosa maintains a delicate balance between immune tolerance to nutrients and harmful components, which is crucial for the digestive system's normal functions. Dietary bioactive peptides positively impact gastrointestinal homeostasis by modulating the barrier function, immune responses, and gut microbiota. However, there is limited clinical evidence on the safety and efficacy of bioactive peptides, much less on the applications of dietary peptides for the treatment or prevention of diseases related to the GIT. Further study is warranted to establish the applications of bioactive peptides in regulating gut health and function.

A Fermented Food Product Containing Lactic Acid Bacteria Protects ZDF Rats from the Development of Type 2 Diabetes

Type 2 diabetes (T2D) is a complex metabolic disease, which involves a maintained hyperglycemia due to the development of an insulin resistance process. Among multiple risk factors, host intestinal microbiota has received increasing attention in T2D etiology and progression. In the present study, we have explored the effect of long-term supplementation with a non-dairy fermented food product (FFP) in Zucker Diabetic and Fatty (ZDF) rats T2D model. The supplementation with FFP induced an improvement in glucose homeostasis according to the results obtained from fasting blood glucose levels, glucose tolerance test, and pancreatic function. Importantly, a significantly reduced intestinal glucose absorption was found in the FFP-treated rats. Supplemented animals also showed a greater survival suggesting a better health status as a result of the FFP intake. Some dissimilarities have been observed in the gut microbiota population between control and FFP-treated rats, and interestingly a tendency for better cardiometabolic markers values was appreciated in this group. However, no significant differences were observed in body weight, body composition, or food intake between groups. These findings suggest that FFP induced gut microbiota modifications in ZDF rats that improved glucose metabolism and protected from T2D development.

Postbiotics: facts and open questions. A position paper on the need for a consensus definition

The past definitions of probiotics and prebiotics have been reviewed and updated recently. According to these concepts, probiotics comprise live microorganisms that confer a health benefit on the host when administered in adequate amounts, whereas a prebiotic is a substrate that is selectively utilised by host microorganisms, conferring a health benefit. The words probiotics and prebiotics can be found on labels of many foods and supplements. Consumers have a growing awareness of these terms' meanings, and many countries are increasingly using them for regulation purposes. At the same time, there is increasing evidence on the health effects of non-viable microorganisms and the metabolites that they can produce by fermentation or by their action on food components. Different terms have been used in the literature to refer to these bioactive compounds, which do not fall under the known categories of probiotics, prebiotics or synbiotics. The tentative term postbiotics has been the most used one so far. However, no definition of the term has gained international consensus to date. This work aims to provide information on the facts and the open questions about the so-called postbiotics.