Exopolysaccharides from Lactobacillus buchneri TCP016 Attenuate LPS- and d-GalN-Induced Liver Injury by Modulating the Gut Microbiota

Effect of Bacillus subtilis isolated from yaks on D-galactose-induced oxidative stress and hepatic damage in mice

Acute hepatic injury is a severe condition that is always accompanied by oxidative stress and inflammation, seriously threatening the health of the host. Probiotics have been shown to be involved in the regulation of antioxidant system and gut microbiota activity, but studies on the effects of yak derived Bacillus subtilis (B. subtilis) on acute liver injury and oxidative stress remain scarce. Here, we aim to explore the ameliorative effects of B. subtilis isolated from yaks on oxidative stress and hepatic injury caused by D-galactose, as well as the underlying processes. Results indicated that B. subtilis administration, particularly the BS3, significantly mitigated hepatic damage induced by D-galactose in mice as evidenced by ameliorating liver tissue damage as well as decreasing ALT (p < 0.05) and AST (p < 0.05) levels. Additionally, the B. subtilis intervention was demonstrated to enhance the antioxidant system in D-galactose-exposed mice, as manifested by increased T-AOC and SOD, alongside a decrease in MDA levels (p < 0.05). Meanwhile, B. subtilis intervention could effectively mitigate oxidative damage via modulating the Keap1/Nrf2 signaling pathway. Importantly, B. subtilis exhibited a pronounced protective effect against D-galactose-induced intestinal barrier dysfunction through improving tight junction proteins. The gut microbiota results suggest that BS3 alters the abundance of some gut flora such as Firmicutes phylum and Oscillibacter and Lachnospiraceae_NK4A136 genera, which affects the composition of the gut microbiota and reverses the decrease in the microbial richness index in mice. In summary, these findings demonstrated that B. subtilis isolated from yaks serve as a promising candidate to ameliorate oxidative damage and hepatic injury. Meanwhile, the positive regulation effect of B. subtilis on gut microbiota and intestinal mucosal barrier may be one of its underlying mechanisms to alleviate oxidative stress and hepatic injury.

Bie Jia Jian pill ameliorates BDL-induced cholestatic hepatic fibrosis in rats by regulating intestinal microbial composition and TMAO-mediated PI3K/AKT signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

As a compound of traditional Chinese medicine (TCM), Bie Jia Jian pill (BJJP) is extensively used to treat the clinical chronic liver disease. Nevertheless, the specific mechanism through which BJJP affects hepatic fibrosis (HF) remains unknown.

AIM OF THE STUDY

To explore the role and potential mechanism of BJJP involved in treating HF.

MATERIALS AND METHODS

HF model of Sprague-Dawley (SD) rats was induced by a bile duct ligation (BDL). The function of BJJP involved in the intestinal microbiota (IM) and its metabolites in BDL-induced HF rats were explored through the 16S rRNA sequencing and untargeted metabolomics technologies. Network pharmacology was used to forecast mechanism underlying BJJP's anti-HF effects, which were validated in BDL-induced rats and trimethylamine N-oxide (TMAO)-induced LX-2 and HSC-T6 cells.

RESULTS

BJJP effectively ameliorated pathological liver damage, inflammation, and fibrosis of the BDL-induced HF rats. BJJP regulated IM diversity and composition and interfered with trimethylamine (TMA)-flavin monooxygenase 3 (FMO3)-TMAO process. In vitro, BJJP significantly inhibited the TMAO-induced activation of hepatic stellate cells (HSCs) (rat HSC cell line, HSC-T6; human HSC cell line, LX-2). Network pharmacology results demonstrated that PI3K/AKT signal pathway is crucially involved in BJJP treatment of HF. Further research revealed that BJJP inhibited the PI3K/AKT signal pathway in BDL-induced HF rats. Moreover, TMAO activated the PI3K/AKT pathway, whereas BJJP suppressed TMAO-induced activation. Subsequent intervention with 740Y-P (the PI3K agonist) successfully neutralized the repression effect on PI3K/AKT signal pathway by BJJP.

CONCLUSION

These results clearly show that BJJP attenuates HF by regulating the IM, as well as inhibiting PI3K/AKT pathway mediated by TMAO.

The Effect of Lactobacillus sakei on Growth Performance and Intestinal Health in Dogs: Gut Microbiota and Metabolism Study

The gut microbiota is the largest and most complex ecosystem consisting of trillions of microorganisms, which influenced by various external factors. As an important probiotic species, Lactobacillus helps to improve gut microbial diversity and composition, underlying potential efficacy in growth performance and disease prevention. However, limited studies have been investigated the relationship between Lactobacillus sakei and intestinal health in dogs. In this study, dogs in the two groups were fed a standard diet (group C, n = 8) and Lactobacillus sakei diet (group P, n = 8), respectively. The growth performance, serum biochemical indices, antioxidant capacity, gut microbiota, and metabolism of dogs in both groups were studied. Results from growth trials showed that L. sakei can significantly improve the growth performance of dogs, including increased weight gain (p < 0.05), serum biochemical indices, i.e., ALP, TP, and ALB (p < 0.05), and better antioxidant capacity, i.e., SOD and GSH-Px (p < 0.05). Significant changes in the gut microbial composition were detected in dogs fed Lactobacillus sakei, as evidenced by an increase in the level of Firmicutes, Spirochaetota, and Patescibacteria, all of them play an important role in maintaining intestinal health. Moreover, a decrease in the level of microorganisms that threaten health, such as Mucispirillum and Clostridium_sensu_stricto_13. The metabolic analysis showed that the Lactobacillus sakei enhanced metabolic pathways such as vitamin B6 metabolism, glutathione metabolism, retinol metabolism, and fatty acid degradation. Our findings suggested that Lactobacillus sakei supplementation had beneficial effects on the growth performance and health status of dogs by improving gut microbiota balance and promoting metabolism. There are an estimated 200 million dogs in China, and the population is continuing to grow at a rapid pace. It is essential to explore an effective way to promote health in dogs. Intestinal diseases, particularly colitis and diarrhea, are common clinical conditions in dogs and are associated with gut microbiota. Lactobacillus sakei, as an important species of probiotics, the relationship between L. sakei and intestinal health in dogs remains unclear. Our study suggests that L. sakei significantly promotes growth performance and health states involving weight gain, regulation of gut microbiota, and metabolism. Overall, our findings shed light on the potential role of L. sakei as an alternative in promoting health in dogs.

Postbiotics as Antiinflammatory and Immune-Modulating Bioactive Compounds in Metabolic Dysfunction-Associated Steatotic Liver Disease

Postbiotics, defined as products or metabolic byproducts secreted by live bacteria or released after bacterial lysis, are emerging as promising therapeutic agents for metabolic dysfunction-associated steatotic liver disease (MASLD). This review explores the antiinflammatory and immunomodulatory properties of various postbiotics, including exopolysaccharides, lipoteichoic acid, short-chain fatty acids, hydrogen sulfide, polyamines, tryptophan derivatives, and polyphenol metabolites. These compounds have demonstrated potential in mitigating steatotic liver infiltration, reducing inflammation, and slowing fibrosis progression in preclinical studies. Notably, postbiotics exert their beneficial effects by modulating gut microbiota composition, enhancing intestinal barrier function, optimizing lipid metabolism, reducing hepatic inflammation and steatosis, and exhibiting hepatoprotective properties. However, translating these findings into clinical practice requires well-designed trials to validate efficacy and safety, standardize production and characterization, and explore personalized approaches and synergistic effects with other therapeutic modalities. Despite challenges, the unique biological properties of postbiotics, such as enhanced safety compared to probiotics, make them attractive candidates for developing novel nutritional interventions targeting the multifactorial pathogenesis of MASLD. Further research is needed to establish their clinical utility and potential to improve liver and systemic outcomes in this increasingly prevalent condition.

Advances in microbial exopolysaccharides as α-amylase inhibitors: Effects, structure-activity relationships, and anti-diabetic effects in vivo

The rapid digestion of starch, as the main source of energy in the human diet, causes an acute increase in blood sugar levels that will affect blood glucose homeostasis. The inhibition of α-amylase activity is an effective way of reducing starch digestibility, thereby controlling postprandial glycemia. As a class of carbohydrate polymers, microbial exopolysaccharides (EPSs) have garnered widespread attention for their inhibitory effects on α-amylase, but there is a lack of comprehensive review in this area. This paper aimed to review the inhibitory activity of microbial EPSs on α-amylase and their interaction mechanisms, and the effect of microbial EPSs on lowering blood glucose levels and regulating glycolipid metabolism in vivo were also discussed. Numerous studies have reported that EPSs with α-amylase inhibition activity are primarily produced by lactic acid bacteria. Microbial EPSs with an appropriate range of molecular weight, high proportion of glucose or mannose or arabinose residues, and high uronic acid content might be acceptable to inhibit α-amylase activity. Additionally, microbial EPSs exhibited potential anti-diabetic effects in mice, reducing blood glucose levels, and regulating glycolipid metabolism and gut microbiota. The information covered in this review may enhance the development and application of EPSs in functional food and pharmaceutical research.

Polysaccharide-mediated modulation of gut microbiota in the treatment of liver diseases: Promising approach with significant challenges

Liver disease represents a significant global health burden, with an increasing prevalence and a lack of efficient treatment options. The microbiota-gut-liver axis involves bidirectional communication between liver function and intestinal microorganisms. A balanced gut flora protects intestinal homeostasis, while imbalances contribute to the development of liver diseases. Distinct alterations in the structure of gut flora during illness are crucial in the management of various liver diseases. Polysaccharides derived from herbal products, fungi, and other sources have been identified to possess diverse biological activities and are well-tolerated in the treatment of liver diseases. This review provides updates on the therapeutic effects of polysaccharides on liver diseases, including fatty liver diseases, acute liver injuries and liver cancers. It also summarizes advancements in understanding the mechanisms involved, particularly from the perspective of gut microbiota and metabolites, by highlighting the changes in the composition of potentially beneficial and harmful bacteria and their correlation with the therapeutic effects of polysaccharides. Additionally, by exploring the structure-activity relationship, our review provides valuable insights for the structural modification of polysaccharides and expanding their applications. In conclusion, this review offers theoretical support and novel perspectives on developing polysaccharides-based therapeutic approaches for the treatment of liver diseases.

Simulated Gastrointestinal Digestion and Fecal Fermentation Characteristics of Exopolysaccharides Synthesized by Schleiferilactobacillus harbinensis Z171

Exopolysaccharides (EPSs) produced by Lactobacillus have important physiological activities and are commonly used as novel prebiotics. A strain of Lactobacillus with high EPS yield was identified as Schleiferilactobacillus harbinensis (S. harbinensis Z171), which was isolated from Chinese sauerkraut. The objective of this study was to investigate the in vitro simulated digestion and fecal fermentation behavior of the purified exopolysaccharide fraction F-EPS1A from S. harbinensis Z171 and its influence on the human intestinal flora composition. The in vitro digestion results showed that the primary structural characteristics of F-EPS1A, such as morphology, molecular weight, and monosaccharide composition remained stable after saliva and gastrointestinal digestion. Compared with the blank group, the fermentation of F-SPS1A by fecal microbiota decreased the diversity of the bacterial communities, significantly promoted the relative abundance of Bifidobacterium and Faecalibacterium, and decreased the relative abundance of Lachnospiraceae_Clostridium, Fusobacterium, and Oscillospira. Reverse transcription polymerase chain reaction (RT-PCR) analysis also showed that the population of Bifidobacterium markedly increased. Furthermore, the total short-chain fatty acid levels increased significantly, especially for butyric acid. Gas chromatography-mass spectrometry (GC-MS) results showed that F-EPS1A could be fermented by the human gut microbiota to synthesize organic acids and derivative metabolites that are beneficial to gut health. Therefore, these findings suggest that F-EPS1A could be exploited as a potential prebiotic.

Postbiotics as Metabolites and Their Biotherapeutic Potential

This review highlights the role of postbiotics, which may provide an underappreciated avenue doe promising therapeutic alternatives. The discovery of natural compounds obtained from microorganisms needs to be investigated in the future in terms of their effects on various metabolic disorders and molecular pathways, as well as modulation of the immune system and intestinal microbiota in children and adults. However, further studies and efforts are needed to evaluate and describe new postbiotics. This review provides available knowledge that may assist future research in identifying new postbiotics and uncovering additional mechanisms to combat metabolic diseases.

Potential of postbiotics for the treatment of metabolic disorders

Postbiotics, the next generation of probiotics, are extracts that are free of living and nonviable bacteria and show strong modulatory effects on the gut flora. Examples include vitamin B12, vitamin K, folate, lipopolysaccharides, enzymes, and short-chain fatty acids (SCFAs), representing a subset of essential nutrients commonly found in the human diet. Postbiotics have been observed to demonstrate antiobesity and antidiabetic effects through a variety of mechanisms. These pathways primarily involve an elevation in energy expenditure, a decrease in the formation and differentiation of adipocytes and food intake, modification of lipid and carbohydrate absorption and metabolism, and regulation of gut dysbiosis. Based on these above effects and mechanisms, the use of postbiotics can be considered as potential strategy for the treatment of metabolic disorders.

Postbiotics: the new horizons of microbial functional bioactive compounds in food preservation and security

In recent decades, consumers, manufacturers, and researchers have been more interested in functional foods, which include probiotics, prebiotics, and postbiotics. Probiotics are live microbes that, when regulated in enough quantities, provide health benefits on the host, while the prebiotics are substrates that host microorganisms selectively use. Postbiotics are metabolites and cell-wall components that are beneficial to the host and are released by living bacteria or after lysis. Postbiotic dietary supplements are more stable than probiotics and prebiotics. Many bioactivities of postbiotics are unknown or poorly understood. Hence, this study aims to present a synopsis of the regular elements and new developments of the postbiotics including health-promoting effects, production, conceptualization of terms, bioactivities, and applications in the field of food safety and preservation. Postbiotics aid in bio preservation and the reduction of biofilm development in food due to their organic acids, bacteriocins, and other antibacterial activities. The present study examines the production of postbiotic metabolites in situ in food and the effects of external and internal food components. The antimicrobial roles, removal of biofilms, and its applications in preservation and food safety have also been discussed. This paper also explored the various aspects like manipulation of postbiotic composition in the food system and its safety measures.

Graphical Abstract

Complete genome analysis of Bacillus velezensis TS5 and its potential as a probiotic strain in mice

Introduction

In recent years, a large number of studies have shown that Bacillus velezensis has the potential as an animal feed additive, and its potential probiotic properties have been gradually explored.

Methods

In this study, Illumina NovaSeq PE150 and Oxford Nanopore ONT sequencing platforms were used to sequence the genome of Bacillus velezensis TS5, a fiber-degrading strain isolated from Tibetan sheep. To further investigate the potential of B. velezensis TS5 as a probiotic strain, in vivo experiments were conducted using 40 five-week-old male specific pathogen-free C57BL/6J mice. The mice were randomly divided into four groups: high fiber diet control group (H group), high fiber diet probiotics group (HT group), low fiber diet control group (L group), and low fiber diet probiotics group (LT group). The H and HT groups were fed high-fiber diet (30%), while the L and LT groups were fed low-fiber diet (5%). The total bacteria amount in the vegetative forms of B. velezensis TS5 per mouse in the HT and LT groups was 1 × 109 CFU per day, mice in the H and L groups were given the same volume of sterile physiological saline daily by gavage, and the experiment period lasted for 8 weeks.

Results

The complete genome sequencing results of B. velezensis TS5 showed that it contained 3,929,788 nucleotides with a GC content of 46.50%. The strain encoded 3,873 genes that partially related to stress resistance, adhesion, and antioxidants, as well as the production of secondary metabolites, digestive enzymes, and other beneficial nutrients. The genes of this bacterium were mainly involved in carbohydrate metabolism, amino acid metabolism, vitamin and cofactor metabolism, biological process, and molecular function, as revealed by KEGG and GO databases. The results of mouse tests showed that B. velezensis TS5 could improve intestinal digestive enzyme activity, liver antioxidant capacity, small intestine morphology, and cecum microbiota structure in mice.

Conclusion

These findings confirmed the probiotic effects of B. velezensis TS5 isolated from Tibetan sheep feces and provided the theoretical basis for the clinical application and development of new feed additives.

Epigallocatechin Gallate Alleviates Staphylococcal Enterotoxin A-Induced Intestinal Barrier Damage by Regulating Gut Microbiota and Inhibiting the TLR4-NF-κB/MAPKs-NLRP3 Inflammatory Cascade

Natural phytochemicals have attracted increasing attention because of their promising ability to tackle bacteriotoxin-induced public safety concerns. However, it is unclear how natural phytochemicals regulate the intestinal barrier dysfunction caused by bacteriotoxin, such as staphylococcal enterotoxin A (SEA). This study aims to illustrate the in vitro and in vivo protective mechanism of epigallocatechin gallate (EGCG) on SEA-triggered intestinal barrier damage and inflammation. Results show that EGCG alleviates intestinal barrier damage by effectively inhibiting SEA-induced intestinal permeability increase, tight junction protein and mucin loss, and intestinal cell apoptosis. EGCG also reduces intestinal inflammation by suppressing the TLR4-NF-κB/MAPKs-NLRP3 pathway. Importantly, EGCG reverses gut microbiota dysbiosis and short-chain fatty acid (SCFA) content decrease induced by SEA. It is worth noting that this study also detects the direct interaction between the phytochemical and virulence factors and finds that EGCG effectively not only inhibits the secretion of SEA but also binds with the secreted SEA to attenuate its toxicity. Taken together, EGCG mitigates SEA-induced intestinal barrier dysfunction via gut microbiota SCFA-mediated TLR4-NF-κB/MAPKs-NLRP3 inflammatory cascade inhibition. Overall, this research provides enlightening insight into the application of bacteriotoxin-targeting natural compounds in the field of food safety and human wellness.

Genome-Wide and 16S rRNA Sequencing-Based Analysis on the Health Effects of Lacticaseibacillus paracasei XLK401 on Chicks

Lacticaseibacillus paracasei, serves as a growth promoter used in the poultry industry, contributeing to broiler development. However, practical studies are needed to determine the probiotic potential and growth-promoting effects of specific L. paracasei strains. This study aims to determine whether L. paracasei XLK401 influences broiler chicken growth and the mechanisms involved. Notably, we identified several bile salt and acid tolerance-related genes (Asp23, atpD, atpA, atpH, and atpF) in L. paracasei XLK401. This bacterium demonstrates robust probiotic properties under acidic conditions (pH 2.0) and 0.3% bile salt conditions. It also contains a variety of antioxidant-related genes (trxA, trxB, and tpx), carbohydrate-related genes, gene-encoding glycosidases (e.g., GH and GT), and three clusters of genes associated with antimicrobial compounds. Supplementation with L. paracasei XLK401 significantly increased the body weight of the chicks. In addition, it significantly increased hepatic antioxidant enzyme activities (GSH-Px, SOD, and T-AOC) while significantly decreasing the levels of oxidative damage factors and inflammatory factors (MDA and IL-6), resulting in improved chick health. Improvements in body weight and health status were associated with significant increases in α-amylase activity and the remodeling of the host gut microbiota by L. paracasei XLK401. Among them, actinobacteria abundance in chicken intestines after feeding them L. paracasei XLK401 was significantly decreased, Bifidobacterium sp. abundance was also significantly decreased, and Subdoligranulum sp. abundance was significantly increased. This suggests that L. paracasei XLK401 can regulate the abundance of certain bacteria without changing the overall microbial structure. In addition, in the correlation analysis, Subdoligranulums sp. were positively correlated with SOD and negatively correlated with IL-1β and MDA. Overall, our study demonstrates that L. paracasei XLK401 effectively promotes healthy chick growth. This is made possible by the modulation of gut microbe abundance and the underlying probiotic effect of L. paracasei XLK401. Based on these findings, we postulate L. paracasei XLK401 as a potential efficient growth promoter in broiler farming.

An exopolysaccharide from Lactobacillus pentosus YY-112: structure and effect on the human intestinal microbiota

The development of novel prebiotics, which could regulate the intestinal microbiota, may help prevent and treat intestinal diseases. Here, we studied a homogeneous polysaccharide, LPE-2, produced by Lactobacillus pentosus YY-112 during fermentation. Methylation and gas chromatography-mass spectrometry analysis, combined with nuclear magnetic resonance results, suggested that the structural unit of LPE-2 comprises a branched mannan moiety and a linear glucan moiety. In vitro simulated intestinal fermentation showed that LPE-2 reduced harmful intestinal gas production and promoted short-chain fatty acid production (especially propionic acid). Moreover, it reduced the relative abundance of Escherichia-Shigella, increased that of Bifidobacterium and Lactobacillus, and had a stronger regulatory effect on intestinal flora in women than in men. The potential sex-specific prebiotic effects of LPE-2 on human intestinal health, were possibly related to its mannan branch with (1→2) and (1→3) linkages and backbones with flexible α configurations, which are sheared and degraded/utilized easier by Bifidobacterium and Lactobacillus.

Lonicera japonica polysaccharides alleviate D-galactose-induced oxidative stress and restore gut microbiota in ICR mice

Lonicera japonica polysaccharides (LJPs) exhibit anti-aging effect in nematodes. Here, we further studied the function of LJPs on aging-related disorders in D-galactose (D-gal)-induced ICR mice. Four groups of mice including the control group, the D-gal-treated group, the intervening groups with low and high dose of LJPs (50 and 100 mg/kg/day) were raised for 8 weeks. The results showed that intragastric administration with LJPs improved the organ indexes of D-gal-treated mice. Moreover, LJPs improved the activity of superoxide dismutase (SOD), catalase (CAT) as well as glutathione peroxidase (GSH-Px) and decreasing the malondialdehyde (MDA) level in serum, liver and brain. Meanwhile, LJPs restored the content of acetylcholinesterase (AChE) in the brain. Further, LJPs reversed the liver tissue damages in aging mice. Mechanistically, LJPs alleviate oxidative stress at least partially through regulating Nrf2 signaling. Additionally, LJPs restored the gut microbiota composition of D-gal-treated mice by adjusting the Firmicutes/Bacteroidetes ratio at the phylum level and upregulating the relative abundances of Lactobacillaceae and Bifidobacteriacesa. Notably, the KEGG pathways involved in hazardous substances degradation and flavone and flavonol biosynthesis were significantly enhanced by LJPs treatment. Overall, our study uncovers the role of LJPs in modulating oxidative stress and gut microbiota in the D-gal-induced aging mice.

Effects of microbial-derived biotics (meta/pharma/post-biotics) on the modulation of gut microbiome and metabolome; general aspects and emerging trends

Potential effects of metabiotics (probiotics effector molecules or signaling factors), pharmabiotics (pro-functional metabolites produced by gut microbiota (GMB)) and postbiotics (multifunctional metabolites and structural compounds of food-grade microorganisms) on GMB have been rarely reviewed. These multifunctional components have several promising capabilities for prevention, alleviation and treatment of some diseases or disorders. Correlations between these essential biotics and GMB are also very interesting and important in human health and nutrition. Furthermore, these natural bioactives are involved in modulation of the immune function, control of metabolic dysbiosis and regulation of the signaling pathways. This review discusses the potential of meta/pharma/post-biotics as new classes of pharmaceutical agents and their effective mechanisms associated with GMB-host cell to cell communications with therapeutic benefits which are important in balance and the integrity of the host microbiome. In addition, cutting-edge findings about bioinformatics /metabolomics analyses related to GMB and these essential biotics are reviewed.

Relationship of Gene-Structure-Antioxidant Ability of Exopolysaccharides Derived from Lactic Acid Bacteria: A Review

Polysaccharides derived from lactic acid bacteria (LAB) have widespread industrial applications owing to their excellent safety profile and numerous biological properties. The antioxidant activity of exopolysaccharides (EPS) offers defense against disease conditions caused by oxidative stress. Several genes and gene clusters are involved in the biosynthesis of EPS and the determination of their structures, which play an important role in modulating their antioxidant ability. Under conditions of oxidative stress, EPS are involved in the activation of the nonenzyme (Keap1-Nrf2-ARE) response pathway and enzyme antioxidant system. The antioxidant activity of EPS is further enhanced by the targeted alteration of their structures, as well as by chemical methods. Enzymatic modification is the most commonly used method, though physical and biomolecular methods are also frequently used. A detailed summary of the biosynthetic processes, antioxidant mechanisms, and modifications of LAB-derived EPS is presented in this paper, and their gene-structure-function relationship has also been explored.

Beyond cellulose: pharmaceutical potential for bioactive plant polysaccharides in treating disease and gut dysbiosis

Polysaccharides derived from plants, algae, or fungi serve as the major components of some human diets. Polysaccharides have been shown to exhibit diverse biological activities in improving human health, and have also been proposed to function as potent modulators of gut microbiota composition, thus playing a bi-directional regulatory role in host health. Here, we review a variety of polysaccharide structures potentially linked to biological functions, and cover current research progress in characterizing their pharmaceutical effects in various disease models, including antioxidant, anticoagulant, anti-inflammatory, immunomodulatory, hypoglycemic, and antimicrobial activities. We also highlight the effects of polysaccharides on modulating gut microbiota via enrichment for beneficial taxa and suppression of potential pathogens, leading to increased microbial expression of carbohydrate-active enzymes and enhanced short chain fatty acid production. This review also discusses polysaccharide-mediated improvements in gut function by influencing interleukin and hormone secretion in host intestinal epithelial cells.

Bacterial exopolysaccharides as emerging bioactive macromolecules: from fundamentals to applications

Microbial exopolysaccharides (EPS) are extracellular carbohydrate polymers forming capsules or slimy coating around the cells. EPS can be secreted by various bacterial genera that can help bacterial cells in attachment, environmental adaptation, stress tolerance and are an integral part of microbial biofilms. Several gut commensals (e.g., Lactobacillus, Bifidobacterium) produce EPS that possess diverse bioactivities. Bacterial EPS also has extensive commercial applications in the pharmaceutical and food industries. Owing to the structural and functional diversity, genetic and metabolic engineering strategies are currently employed to increase EPS production. Therefore, the current review provides a comprehensive overview of the fundamentals of bacterial exopolysaccharides, including their classification, source, biosynthetic pathways, and functions in the microbial community. The review also provides an overview of the diverse bioactivities of microbial EPS, including immunomodulatory, anti-diabetic, anti-obesity, and anti-cancer properties. Since several gut microbes are EPS producers and gut microbiota helps maintain a functional gut barrier, emphasis has been given to the intestinal-level bioactivities of the gut microbial EPS. Collectively, the review provides a comprehensive overview of microbial bioactive exopolysaccharides.

Exopolysaccharides from lactic acid bacteria, as an alternative to antibiotics, on regulation of intestinal health and the immune system

Over-use or misuse of antibiotics in livestock and poultry production contributes to the rising threat of antibiotic resistance in animals and has negative ecological effects. Exopolysaccharides from lactic acid bacteria (LAB-EPS) are a class of biological macromolecules which are secreted by lactic acid bacteria to the outside of the cell wall during their growth and metabolism. Numerous studies demonstrated that LAB-EPS have anti-inflammatory and antimicrobial activities and are able to regulate intestinal health and the immune system in livestock. They are biodegradable, nontoxic and bio-compatible, which are considered as ideal alternatives to antibiotics. This review aims to discuss and summarize recent research findings of LAB-EPS on regulation of intestinal health and the immune system in animals, and thus provide scientific justification for commercial applications of LAB-EPS in livestock.

Health Benefits of Consuming Foods with Bacterial Probiotics, Postbiotics, and Their Metabolites: A Review

Over the years, probiotics have been extensively studied within the medical, pharmaceutical, and food fields, as it has been revealed that these microorganisms can provide health benefits from their consumption. Bacterial probiotics comprise species derived from lactic acid bacteria (LAB) (genus Lactobacillus, Leuconostoc, and Streptococcus), the genus Bifidobacterium, and strains of Bacillus and Escherichia coli, among others. The consumption of probiotic products is increasing due to the current situation derived from the pandemic caused by COVID-19. Foods with bacterial probiotics and postbiotics are premised on being healthier than those not incorporated with them. This review aims to present a bibliographic compilation related to the incorporation of bacterial probiotics in food and to demonstrate through in vitro and in vivo studies or clinical trials the health benefits obtained with their metabolites and the consumption of foods with bacterial probiotics/postbiotics. The health benefits that have been reported include effects on the digestive tract, metabolism, antioxidant, anti-inflammatory, anticancer, and psychobiotic properties, among others. Therefore, developing food products with bacterial probiotics and postbiotics is a great opportunity for research in food science, medicine, and nutrition, as well as in the food industry.

Radix paeoniae alba polysaccharide attenuates lipopolysaccharide-induced intestinal injury by regulating gut microbiota

Accumulating evidence indicated that oxidative stress is closely related to inflammation and the progression of multiple chronic diseases, which seriously threaten the host health. Currently, multiple plant-derived polysaccharides have been demonstrated to ameliorate the negative effects of oxidative stress on the host, but the potential protective effect of radix paeoniae alba polysaccharide (RPAP) on host have not been well characterized. Here, we investigated whether different doses of RPAP administration could alleviate lipopolysaccharide (LPS)-induced intestinal injury and gut microbial dysbiosis in mice. Results indicated that RPAP administration effectively alleviated LPS-induced intestinal damage in dose dependent. Additionally, amplicon sequencing showed that RPAP administration reversed the significant decrease in gut microbial diversity caused by LPS exposure and restored the alpha-diversity indices to normal levels. Microbial taxonomic investigation also indicated that LPS exposure resulted in significant changes in the gut microbial composition, characterized by a decrease in the abundances of beneficial bacteria (Lactobacillus, Alistipes, Bacillus, Rikenellaceae_RC9_gut_group, etc.) and an increase in the contents of pathogenic bacteria (Klebsiella, Helicobacter, Enterococcus, etc.). However, RPAP administration, especially in high doses, could improve the composition of the gut microbiota by altering the abundance of some bacteria. Taken together, this study demonstrated that RPAP administration could ameliorate LPS-induced intestinal injury by regulating gut microbiota. Meanwhile, this also provides the basis for the popularization and application of RPAP and alleviating oxidative stress from the perspective of gut microbiota.

Complete genome analysis of Bacillus subtilis derived from yaks and its probiotic characteristics

Probiotics have attracted attention due to their multiple health benefits to the host. Yaks inhabiting the Tibetan plateau exhibit excellent disease resistance and tolerance, which may be associated with their inner probiotics. Currently, research on probiotics mainly focuses on their positive effects on the host, but information regarding their genome remains unclear. To reveal the potential functional genes of Bacillus subtilis isolated from yaks, we sequenced its whole genome. Results indicated that the genomic length of Bacillus subtilis was 866,044,638 bp, with 4,429 coding genes. The genome of this bacteria was composed of one chromosome and one plasmid with lengths of 4,214,774 and 54,527 bp, respectively. Moreover, Bacillus subtilis contained 86 tRNAs, 27 rRNAs (9 16S_rRNA, 9 23S_rRNA, and 9 5S_rRNA), and 114 other ncRNA. KEGG annotation indicated that most genes in Bacillus subtilis were associated with biosynthesis of amino acids, carbon metabolism, purine metabolism, pyrimidine metabolism, and ABC transporters. GO annotation demonstrated that most genes in Bacillus subtilis were related to nucleic acid binding transcription factor activity, transporter activity, antioxidant activity, and biological adhesion. EggNOG uncovered that most genes in Bacillus subtilis were related to energy production and conversion, amino acid transport and metabolism, carbohydrate transport and metabolism. CAZy annotation found glycoside hydrolases (33.65%), glycosyl transferases (22.11%), polysaccharide lyases (3.84%), carbohydrate esterases (14.42%), auxiliary activities (3.36%), and carbohydrate-binding modules (22.59%). In conclusion, this study investigated the genome and genetic properties of Bacillus subtilis derived from yaks, which contributed to understanding the potential prebiotic mechanism of probiotics from the genetic perspective.

Targeted modulation of gut microbiota by traditional Chinese medicine and natural products for liver disease therapy

The gut microbiota not only constitutes intestinal microenvironment homeostasis and human health but also exerts indispensable roles in the occurrence and progression of multiple liver diseases, including alcohol-related liver disease, nonalcoholic fatty liver disease, autoimmune liver disease and liver cancer. Given the therapeutic status of these diseases, their prevention and early therapy are crucial, and the detailed mechanism of gut microbiota in liver disease urgently needs to be explored. Meanwhile, multiple studies have shown that various traditional Chinese medicines, such as Si Miao Formula, Jiangzhi Granules, Liushen Capsules, Chaihu-Shugan Power, Cassiae Semen and Gynostemma, as well as some natural products, including Costunolide, Coprinus comatus polysaccharide, Antarctic krill oil, Oridonin and Berberine, can repair liver injury, improve fatty liver, regulate liver immunity, and even inhibit liver cancer through multiple targets, links, and pathways. Intriguingly, the aforementioned effects demonstrated by these traditional Chinese medicines and natural products have been shown to be closely related to the gut microbiota, directly driving the strategy of traditional Chinese medicines and natural products to regulate the gut microbiota as one of the breakthroughs in the treatment of liver diseases. Based on this, this review comprehensively summarizes and discusses the characteristics, functions and potential mechanisms of these medicines targeting gut microbiota during liver disease treatment. Research on the potential effects on gut microbiota and the regulatory mechanisms of traditional Chinese medicine and natural products provides novel insights and significant references for developing liver disease treatment strategies. In parallel, such explorations will enhance the comprehension of traditional Chinese medicine and natural products modulating gut microbiota during disease treatment, thus facilitating their clinical investigation and application.

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.

Bacterial polysaccharides-A big source for prebiotics and therapeutics

Bacterial polysaccharides are unique due to their higher purity, hydrophilic nature, and a finer three-dimensional fibrous structure. Primarily, these polymers provide protection, support, and energy to the microorganism, however, more recently several auxiliary properties of these biopolymers have been unmasked. Microbial polysaccharides have shown therapeutic abilities against various illnesses, augmented the healing abilities of the herbal and Western medicines, improved overall health of the host, and have exerted positive impact on the growth of gut dwelling beneficial bacteria. Specifically, the review is discussing the mechanism through which bacterial polysaccharides exert anti-inflammatory, antioxidant, anti-cancer, and anti-microbial properties. In addition, they are holding promising application in the 3D printing. The review is also discussing a perspective about the metagenome-based screening of polysaccharides, their integration with other cutting-edge tools, and synthetic microbiome base intervention of polysaccharides as a strategy for prebiotic intervention. This review has collected interesting information about the bacterial polysaccharides from Google Scholar, PubMed, Scopus, and Web of Science databases. Up to our knowledge, this is the first of its kind review article that is summarizing therapeutic, prebiotics, and commercial application of bacterial polysaccharides.

Integrated Bacteria-Fungi Diversity Analysis Reveals the Gut Microbial Changes in Buffalo With Mastitis

The gut microbial community is closely related to mastitis, but studies regarding the influences of mastitis on gut microbiota in buffalo remain scarce. Herein, we characterized the differences in gut bacterial and fungal communities between mastitis-affected and healthy buffalos. Interestingly, although mastitis had no effect on gut bacterial and fungal diversities in the buffalos, some bacterial and fungal taxa were significantly altered. Bacterial and fungal taxonomic analysis showed that the preponderant bacterial phyla (Firmicutes and Bacteroidetes) and fungal phyla (Ascomycota and Basidiomycota) in buffalo were the same regardless of health status. At the level of genus, the changes in some gut bacterial and fungal abundances between both groups were gradually observed. Compared with healthy buffalos, the proportions of 3 bacterial genera (uncultured_bacterium_f_Muribaculaceae, Eubacterium_nodatum_group, and Lachnoclostridium_10) and 1 fungal genus (Pichia) in the mastitis-affected buffalo were significantly increased, whereas 4 bacterial genera (Ruminococcus_2, Candidatus_Stoquefichus, Turicibacter, and Cellulosilyticum) and 4 fungal genera (Cladosporium, Thermothelomyces, Ganoderma and Aspergillus) were significantly decreased. Taken together, this research revealed that there was significant difference in the compositions of the gut microbial community between the healthy and mastitis-affected buffalos. To our knowledge, this is the first insight into the characteristics of the gut microbiota in buffalos with mastitis, which is beneficial to understand the gut microbial information of buffalo in different health states and elucidate the pathogenesis of mastitis from the gut microbial perspective.

Broussonetia papyrifera Polysaccharide Alleviated Acetaminophen-Induced Liver Injury by Regulating the Intestinal Flora

Liver injury caused by an overdose of acetaminophen (APAP) is a major public health problem. This study aimed to evaluate the effects of Broussonetia papyrifera polysaccharide (BPP) on liver injury and intestinal flora induced by APAP. The results showed that BPP could protect against APAP-induced liver injury, alleviate liver apoptosis, improve antioxidant capacity and enhance the liver’s detoxification ability to APAP. At the same time, BPP improved the intestinal flora disorder caused by APAP. More importantly, we found that the hepatoprotective effect of BPP disappeared after the depletion of gut microbiota in mice. Further, we reconstructed the intestinal flora structure of mice through fecal microbiota transplantation and found that the symptoms of APAP—induced liver injury were effectively alleviated. Overall, BPP was a potential hepatoprotective drug that could protect against APAP-induced liver injury and might be mediated by intestinal flora.

Postbiotics as potential new therapeutic agents for metabolic disorders management

The prevalence of obesity, diabetes, non-alcoholic fatty liver disease, and related metabolic disorders has been steadily increasing in the past few decades. Apart from the establishment of caloric restrictions in combination with improved physical activity, there are no effective pharmacological treatments for most metabolic disorders. Many scientific-studies have described various beneficial effects of probiotics in regulating metabolism but others questioned their effectiveness and safety. Postbiotics are defined as preparation of inanimate microorganisms, and/or their components, which determine their safety of use and confers a health benefit to the host. Additionally, unlike probiotics postbiotics do not require stringent production/storage conditions. Recently, many lines of evidence demonstrated that postbiotics may be beneficial in metabolic disorders management via several potential effects including anti-inflammatory, antibacterial, immunomodulatory, anti-carcinogenic, antioxidant, antihypertensive, anti-proliferative, and hypocholesterolaemia properties that enhance both the immune system and intestinal barrier functions by acting directly on specific tissues of the intestinal epithelium, but also on various organs or tissues. In view of the many reports that demonstrated the high biological activity and safety of postbiotics, we summarized in the present review the current findings reporting the beneficial effects of various probiotics derivatives for the management of metabolic disorders and related alterations.

Multiple Intestinal Bacteria Associated with the Better Protective Effect of Bifidobacterium pseudocatenulatum LI09 against Rat Liver Injury

Bifidobacterium pseudocatenulatum LI09 could protect rats from D-galactosamine- (D-GalN-) induced liver injury. However, individual difference in the protective effects of LI09 on the liver injury remains poorly understood. The present study is aimed at determining the multiple intestinal bacteria associated with the better protective effect of LI09 against D-GalN-induced rat liver injury. Two rat cohorts, i.e., the nonsevere and severe cohorts, were divided based on their liver injury severity. Higher level of ALB and lower levels of ALT, AST, TBA, TB, IL-5, and MIP-3α were determined in the nonsevere cohort than the severe cohort. The alpha diversity indices (i.e., observed species, Shannon, and Pielou indices) did not yield significant differences between the intestinal microbiota of the nonsevere and severe cohorts. The intestinal microbiota composition was different between the two cohorts. Ten phylotypes assigned to Bacteroides, Clostridia_UCG-014, Clostridium Lachnospiraceae, Lachnospiraceae_NK4A136, and Parabacteroides were closely associated with the nonsevere cohort, among which, ASV8_Lachnospiraceae_NK4A136 was the most associated one. At the structure level, two groups of phylotypes with most correlations were determined in the intestinal microbiota networks of the two cohorts. Among them, ASV135_Lachnospiraceae_NK4A136 was the most powerful gatekeeper in the microbiota network of the nonsevere cohort. In conclusion, some intestinal bacteria, e.g., Lachnospiraceae_NK4A136, Parabacteroides, and Clostridium, were associated with the better protective effect of LI09 against D-GalN-induced rat liver injury. They were likely to enhance the effectiveness of LI09, and their clinical application deserves further investigation.

Lactobacillus acidophilus LA85 ameliorates cyclophosphamide-induced immunosuppression by modulating Notch and TLR4/NF-κB signal pathways and remodeling the gut microbiota

With the prevalence of coronavirus disease 2019 (COVID-19), we found that probiotics may be effective in organism immune recovery and remodeling of gut microbiota in their patients and recovered individuals....

The Probiotic Properties of Lactic Acid Bacteria and Their Applications in Animal Husbandry

The intestinal tract of animals is a complex ecosystem in which nutrients, microbiota and host cells interact extensively. Probiotics can be considered as part of the natural microbiota of the gut and are involved in improving homeostasis. Lactic acid bacteria (LAB) is a general term for a class of non-spore forming, gram-positive bacteria whose main product of fermented sugar is lactic acid. LAB are considered to be a type of probiotic due to their health-promoting effects on the host, and are very effective in the treatment of human and animal diseases. LAB have been widely used as a class of microbial agents in the field of livestock and poultry breeding. They are also considered to be the best substitutes for antibiotics to improve animal health. Here, we review the biological functions, probiotic characteristics and applications of LAB in livestock and poultry breeding. This review is designed to provide a theoretical base for the in-depth exploration and promotion of LAB use in animal diets.

Exopolysaccharides from a Scandinavian fermented milk viili increase butyric acid and Muribaculum members in the mouse gut

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Bioactivity of viili exopolysaccharide (VEPS) were determined in young male mice.

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Mice drank daily tap water supplemented with VEPS, stressless administration.

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A low dose VEPS modified mildly but significantly the gut microbiota.

Starter culture of viili contains lactic acid bacteria belonging to Lactococcus lactis. These bacteria secrete large polysaccharides (EPSs) into milk, resulting in a ropy texture of viili. In mouse experiments, a large dose of EPS (5–140 mg/day) has been shown to alleviate severity of artificially induced illness through modulation of the gut microbiota. The present study investigated whether supplementary amounts of EPS affects the gut microbiota of normal mouse. EPS with high glucosamine content (VEPS) was isolated from home-made viili. C57BL/6J male mice fed ordinary diet took 49 ± 1 μg VEPS/day for 28 days by drinking ad libitum tap water containing 8 μg/mL VEPS. The relative abundance of Muribaculum increased significantly by VEPS supplementation. The relative abundance of fecal butyric acid decreased in control mice, and VEPS prevented this decrease. These findings indicated that the gut microbiota can be modulated by a small dose of VEPS.

Gut Microbiota Modulation by Polyphenols from Aronia melanocarpa of LPS-Induced Liver Diseases in Rats

Aronia melanocarpa polyphenols (AMPs) can alleviate the degree of liver diseases in rats. However, the mechanism by which this is achieved through gut microbiota modulation remains unclear. Here, a rich-polyphenol extract of A. melanocarpa (AMPs) was used to treat lipopolysaccharide (LPS)-induced liver diseases in rats. To gain insights into the anti-LPS-induced liver disease, liver function index, expression of apoptosis proteins, inflammatory factors, and activation of inflammatory signaling pathways were determined with western blot analysis, immunohistochemistry, and 16S rRNA sequencing or quantitative real-time polymerase chain reaction (qRT-PCR). After AMPs treatment, the gut microbiota composition was modulated, promoting the intestinal barrier function by increasing the expression of intestinal epithelial cell tight junction proteins to reduce the LPS content in serum. The expression levels of inflammatory factors interleukin 6 (IL-6), interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), and related mRNAs were reduced. These results showed that AMPs, as a bioactive substance, could enhance the intestinal barrier function and modulate the gut microbiota of LPS-induced liver diseases.

Lactobacillus plantarum Y44 alleviates oxidative stress by regulating gut microbiota and colonic barrier function in Balb/C mice with subcutaneous d-galactose injection

Probiotics have been proved to ameliorate the symptoms of the host induced by oxidative stress. In this study, the protective effects of Lactobacillus plantarum Y44 on Balb/C mice injured by d-galactose (d-gal)-injection were examined. Six weeks of continuous subcutaneous d-gal injection caused liver and colon injury of the Balb/C mice. L. plantarum Y44 administration significantly reversed the injury by modulating hepatic protein expressions related to the Nrf-2/Keap-1 pathway, and enhancing expressions of colonic tight junction proteins. L. plantarum Y44 administration restored the d-gal injection-induced gut microbiota imbalance by manipulating the ratio of Firmicutes/Bacteroidetes (F/B) and Proteobacteria relative abundance at the phylum level, and manipulating relative abundances of Lactobacillaceae, Muribaculaceae, Ruminococcaceae, Desulfovibrionaceae, and Prevotellaceae at the family level. Moreover, the d-gal injection-induced glycerophospholipid metabolism disorder was ameliorated, evidenced by the decline of phosphatidyl ethanolamine (PE), phosphatidylcholine (PC), phosphatidyl serine (PS), and lysophosphatidyl choline (LysoPC) levels in the serum of the mice after the L. plantarum Y44 administration. Spearman correlation analysis revealed a significant correlation between changes in gut microbiota composition, glycerophospholipid levels, and oxidative stress-related indicators. In summary, L. plantarum Y44 administration ameliorated d-gal injection-induced oxidative stress in Balb/C mice by manipulating gut microbiota and intestinal barrier function, and further influenced the glycerophospholipid metabolism and hepatic Nrf-2/Keap-1 pathway-related protein expressions.

Modulation of gut homeostasis by exopolysaccharides from Aspergillus cristatus (MK346334), a strain of fungus isolated from Fuzhuan brick tea, contributes to immunomodulatory activity in cyclophosphamide-treated mice

In this study, the crude exopolysaccharides (CEPSs) from fungus Aspergillus cristatus (MK346334, NCBI) isolated from Fuzhuan brick tea and its main purified fraction (EPSs-2) were investigated. Using the RAW264.7 cell model, EPSs-2 exhibited an excellent immunomodulatory effect in vitro. Then, the regulating effects of EPSs on immune function and gut microbiota were evaluated using a cyclophosphamide (Cy)-induced mice model. It was found that both CEPSs and EPSs-2 improved the body weight loss, immune organ indexes as well as the levels of TNF-α, IL-1β, IFN-γ and IgA, exhibiting potent immunoregulatory activity. Moreover, CEPSs and EPSs-2 not only attenuated the intestinal tissue damage, but also promoted the production of short-chain fatty acids and modulated the microbial composition by increasing the growth of Muribaculaceae, Prevotellaceae_UCG-001, Bacteroides, Parabacteroides and Tidjanibacter, while decreasing the relative abundances of Helicobacter, Bilophila, Mucispirillum, Lachnospiraceae, Ruminococcaceae and Clostridiales. These results indicated that the EPSs, especially EPSs-2, exhibited immunomodulatory activity associated with the modulation of gut microbiota to maintain gut homeostasis, which provided evidence for the development of novel potential prebiotics and immunomodulators.

The effects of exopolysaccharides and exopolysaccharide-producing Lactobacillus on the intestinal microbiome of zebrafish (Danio rerio)

BACKGROUND

Numerous studies have reported the health-promoting effects of exopolysaccharides (EPSs) in in vitro models; however, a functional evaluation of EPSs will provide additional knowledge of EPS-microbe interactions by in vivo intestinal microbial model. In the present study, high-throughput amplicon sequencing, short-chain fatty acid (SCFAs) and intestinal inflammation evaluation were performed to explore the potential benefits of exopolysaccharides (EPSs) and EPS-producing Lactobacillus (HNUB20 group) using the healthy zebrafish (Danio rerio) model.

RESULTS

The results based on microbial taxonomic analysis revealed that the abundance of four genera, Ochrobactrum, Sediminibacterium, Sphingomonas and Sphingobium, were increased in the control group in comparison to HNUB20 group. Pelomonas spp. levels were significantly higher and that of the genera Lactobacillus and Brachybacterium were significantly decreased in EPS group compared with control group. PICRUSt based functional prediction of gut microbiota metabolic pathways indicated that significantly lower abundance was found for transcription, and membrane transport, whereas folding, sorting and degradation and energy metabolism had significantly higher abundance after HNUB20 treatment. Two metabolic pathways, including metabolism and endocrine functions, were more abundant in the EPS group than control group. Similar to the HNUB20 group, transcription was also decreased in the EPS group compared with the control group. However, SCFAs and immune indexes indicated EPS and HNUB20 performed limited efficacy in the healthy zebrafish.

CONCLUSIONS

The present intestinal microbial model-based study indicated that EPSs and high-yield EPS-producing Lactobacillus can shake the structure of intestinal microbiota, but cannot change SCFAs presence and intestinal inflammation.

Postbiotics-parabiotics: the new horizons in microbial biotherapy and functional foods

Probiotics have several health benefits by modulating gut microbiome; however, techno-functional limitations such as viability controls have hampered their full potential applications in the food and pharmaceutical sectors. Therefore, the focus is gradually shifting from viable probiotic bacteria towards non-viable paraprobiotics and/or probiotics derived biomolecules, so-called postbiotics. Paraprobiotics and postbiotics are the emerging concepts in the functional foods field because they impart an array of health-promoting properties. Although, these terms are not well defined, however, for time being these terms have been defined as here. The postbiotics are the complex mixture of metabolic products secreted by probiotics in cell-free supernatants such as enzymes, secreted proteins, short chain fatty acids, vitamins, secreted biosurfactants, amino acids, peptides, organic acids, etc. While, the paraprobiotics are the inactivated microbial cells of probiotics (intact or ruptured containing cell components such as peptidoglycans, teichoic acids, surface proteins, etc.) or crude cell extracts (i.e. with complex chemical composition)". However, in many instances postbiotics have been used for whole category of postbiotics and parabiotics. These elicit several advantages over probiotics like; (i) availability in their pure form, (ii) ease in production and storage, (iii) availability of production process for industrial-scale-up, (iv) specific mechanism of action, (v) better accessibility of Microbes Associated Molecular Pattern (MAMP) during recognition and interaction with Pattern Recognition Receptors (PRR) and (vi) more likely to trigger only the targeted responses by specific ligand-receptor interactions. The current review comprehensively summarizes and discussed various methodologies implied to extract, purify, and identification of paraprobiotic and postbiotic compounds and their potential health benefits.

Efficacy of Artemisia annua L. extract for recovery of acute liver failure

Artemisia annua L. is an annual herb belonging to the Asteraceae family. It is commonly grown in parts of Asia, including Korea and China, and is called by its nickname Gae-ddong-ssuk, or Chung-ho. The herb is well known for its positive effects on fever and hemostasis, as well as its antibiotic effects. To evaluate the protective properties of A. annua L. on the liver, an acute liver failure animal model was set up with intraperitoneal injection of lipopolysaccharide (LPS) and D-galactosamine (D-galN) in C57BL/6J mice, showing increased levels of AST (aspartate transaminase) and ALT (alanine transaminase). Oral administration of the extract of A. annua L. (EAA) for 2 weeks reduced the level of AST and ALT up to 50% of the levels in the negative control group treated with water vehicle. The efficacy of EAA was more effective than that in a comparative positive control group treated with milk thistle extract. Moreover, EAA protected hepatic cells and tissues from oxidative stresses and inflammatory damages, showing downregulation of inflammatory cytokines such as interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). We also found that LPS stimulated the mouse macrophage cell line, Raw264.7, and secreted a tremendous level of proinflammatory cytokines and the secretion of these cytokines was reduced with EAA treatment via downregulation of mitogen-activated protein kinase phosphorylation and p65 translocation. This study demonstrated that A. annua L. extract is a promising treatment for protection against and recovery from liver damage, as well as maintenance of liver health.

Exopolysaccharides from Lactobacillus kiferi as adjuvant enhanced the immuno-protective against Staphylococcus aureus infection

Exopolysaccharides from lactic acid bacteria (LAB) have gained more attention due to their health benefits. Most research on LAB EPS focuses on antitumor and antioxidant activities. To our knowledge, the immunoadjuvant activity of LAB EPS has not been thoroughly studied. In this study, the EPS produced by Lactobacillus kiferi WXD029 were purified by ethanol precipitation and column chromatography fractionation. The molecular weight of the EPS was 3.423 × 10⁵ Da and was mainly composed of Glu, GlcN, and GalN in a molar ratio of 3.1:1:1. In vitro, EPS could significantly enhance the proliferation and phagocytic activity as well as induce the production of NO, TNF-α, IL-1β, and IL-6 in RAW264.7 cells. In vivo, the EPS adjuvant could increase the titers of S.aureus antigen-specific antibodies and markedly enhanced T cell proliferation. Notably, EPS adjuvant also induced a strong potential Th1, Th2 and Th17-cell mixture responses. Furthermore, immunization with S.aureus antigen plus EPS adjuvant induced a protective effect when compared with S.aureus antigen alone in murine bacteremia, pneumonia and mastitis model. Collectively, these results suggest that EPS derived from probiotic Lactobacillus kiferi strain is promising as an efficient adjuvant candidate for the prevention of S. aureus infections.