The potential role of Bifidobacterium spp. as a preventive and therapeutic agent in controlling inflammation via affecting inflammatory signalling pathways

Taxonomic and phenotypic analysis of bifidobacteria isolated from IBD patients as potential probiotic strains

BACKGROUND

Inflammatory Bowel Diseases (IBD) are a major public health issue with unclear aetiology. Changes in the composition and functionality of the intestinal microbiota are associated with these pathologies, including the depletion of strict anaerobes such as Feacalibacterium prausnitzii. Less evidence is observed for depletion in other anaerobes, among which bifidobacteria. This study characterized the taxonomic and functional diversity of bifidobacteria isolated from the human intestinal microbiota in active and non-active IBD patients by a culturomics approach and evaluated if these bifidobacteria might be used as probiotics for gut health.

RESULTS

A total of 341 bifidobacteria were isolated from the intestinal microbiota of IBD patients (52 Crohn's disease and 26 ulcerative colitis patients), with a high proportion of Bifidobacterium dentium strains (28% of isolated bifidobacteria). In ulcerative colitis, the major species identified was B. dentium (39% of isolated bifidobacteria), in active and non-active ulcerative colitis. In Crohn's disease, B. adolescentis was the major species isolated from non-active patients (40%), while similar amounts of B. dentium and B. adolescentis were found in active Crohn's disease patients. The relative abundance of B. dentium was increased with age, both in Crohn's disease and ulcerative colitis and active and non-active IBD patients. Antibacterial capacities of bifidobacteria isolated from non-active ulcerative colitis against Escherichia coli LF82 and Salmonella enterica ATCC 14028 were observed more often compared to strains isolated from active ulcerative colitis. Finally, B. longum were retained as strains with the highest probiotic potential as they were the major strains presenting exopolysaccharide synthesis, antibacterial activity, and anti-inflammatory capacities. Antimicrobial activity and EPS synthesis were further correlated to the presence of antimicrobial and EPS gene clusters by in silico analysis.

CONCLUSIONS

Different bifidobacterial taxonomic profiles were identified in the microbiota of IBD patients. The most abundant species were B. dentium, mainly associated to the microbiota of ulcerative colitis patients and B. adolescentis, in the intestinal microbiota of Crohn's disease patients. Additionally, the relative abundance of B. dentium significantly increased with age. Furthermore, this study evidenced that bifidobacteria with probiotic potential (antipathogenic activity, exopolysaccharide production and anti-inflammatory activity), especially B. longum strains, can be isolated from the intestinal microbiota of both active and non-active Crohn's disease and ulcerative colitis patients.

Hippuric acid alleviates dextran sulfate sodium-induced colitis via suppressing inflammatory activity and modulating gut microbiota

Inflammatory bowel disease (IBD) is a chronic inflammatory disease associated with metabolic disorder and gut dysbiosis. Decreased abundance of hippuric acid (HA) was found in patients with IBD. HA, metabolized directly from benzoic acid in the intestine and indirectly from polyphenols, serves as a marker of polyphenol catabolism. While polyphenols and benzoic acid have been shown to alleviate intestinal inflammation, the role of HA in this context remains unknown. Herein, we investigated the effects and mechanism of HA on DSS-induced colitis mice. The results revealed that HA alleviated clinical activity and intestinal barrier damage, decreased pro-inflammatory cytokine production. Metagenomic sequencing suggested that HA treatment restored the gut microbiota, including an increase in beneficial gut bacteria such as Adlercreutzia, Eubacterium, Schaedlerella and Bifidobacterium_pseudolongum. Furthermore, we identified 113 candidate genes associated with IBD that are potentially under HA regulation through network pharmacological analyses. 10 hub genes including ALB, IL-6, HSP90AA1, and others were identified using PPI analysis and validated using molecular docking and mRNA expression analysis. Additionally, KEGG analysis suggested that the renin-angiotensin system (RAS), NF-κB signaling and Rap1 signaling pathways were important pathways in the response of HA to colitis. Thus, HA may provide novel biotherapy options for IBD.

Selenium Yeast Alleviates Dextran Sulfate Sodium-Induced Chronic Colitis in Mice by Reducing Proinflammatory Cytokines and Regulating the Gut Microbiota and Their Metabolites

Background

Inflammatory bowel disease (IBD) is a chronic recurrent gastrointestinal inflammatory disease. Selenium has been reported to have therapeutic potential in IBD. Selenium yeast is a common selenium supplement that is convenient to access. This study explored the effect of selenium yeast on dextran sulfate sodium- (DSS-)induced chronic colitis in mice.

Methods

Mice were randomly divided into four groups: the control group, selenium yeast group, chronic colitis group, and chronic colitis+selenium yeast group (n=6). Mice were killed on the 26th day. The disease activity index (DAI) score and histological damage score were calculated. Cytokines, serum selenium, colonic tissue selenium, gut microbiota and their metabolites short-chain fatty acids (SCFAs) were evaluated.

Results

Selenium yeast lowered IL-1β, IL-6, TNF-α, IL-17A, IL-22 and IFN-γ (P<0.05). In addition, selenium yeast significantly elevated Turicibacter, Bifidobacterium, Allobaculum, Prevotella, Halomonas, Adlercreutzia (P<0.05), and butyric acid (P<0.05).

Conclusion

Selenium yeast could improve DSS-induced chronic colitis in mice by regulating cytokines, gut microbiota and their metabolites.

Probiotic characterization of Bacillus smithii: Research advances, concerns, and prospective trends

Bacillus smithii is a thermophilic Bacillus that can be isolated from white wine, hot spring soil, high-temperature compost, and coffee grounds, with various biofunctions and wide applications. It is resistant to both gastric acid and high temperature, which makes it easier to perform probiotic effects than traditional commercial probiotics, so it can maintain good vitality during food processing and has great application prospects. This paper starts with the taxonomy and genetics and focuses on aspects, including genetic transformation, functional enzyme production, waste utilization, and application in the field of food science as a potential probiotic. According to available studies during the past 30 years, we considered that B. smithii is a novel class of microorganisms with a wide range of functional enzymes such as hydrolytic enzymes and hydrolases, as well as resistance to pathogenic bacteria. It is available in waste degradation, organic fertilizer production, the feed and chemical industries, the pharmaceutical sector, and food fortification. Moreover, B. smithii has great potentials for applications in the food industry, as it presents high resistance to the technological processes that guarantee its health benefits. It is also necessary to systematically evaluate the safety, flavor, and texture of B. smithii and explore its biological mechanism of action, which is of great value for further application in multiple fields, especially in food and medicine.

Probiotics as functional foods: How probiotics can alleviate the symptoms of neurological disabilities

Neurological disorders are diseases of the central nervous system with progressive loss of nervous tissue. One of the most difficult problems associated with neurological disorders is that there is no clear treatment for these diseases. In this review, the physiopathology of some neurodegenerative diseases, etiological causes, drugs used and their side effects, and finally the role of probiotics in controlling the symptoms of these neurodegenerative diseases are presented. Recently, researchers have focused more on the microbiome and the gut-brain axis, which may play a critical role in maintaining brain health. Probiotics are among the most important bacteria that have positive effects on the balance of homeostasis via influencing the microbiome. Other important functions of probiotics in alleviating symptoms of neurological disorders include anti-inflammatory properties, short-chain fatty acid production, and the production of various neurotransmitters. The effects of probiotics on the control of abnormalities seen in neurological disorders led to probiotics being referred to as "psychobiotic. Given the important role of the gut-brain axis and the imbalance of the gut microbiome in the etiology and symptoms of neurological disorders, probiotics could be considered safe agents that positively affect the balance of the microbiome as complementary treatment options for neurological disorders.

Probiotics in irritable bowel syndrome and inflammatory bowel disease: review of mechanisms and effectiveness

PURPOSE OF REVIEW

The gastrointestinal (GI) microbiome has been implicated in the pathogenesis of inflammatory bowel disease (IBD) and has been linked with irritable bowel syndrome (IBS). The aim of this article is to critically review the emerging evidence for the mechanisms and effectiveness of probiotics in the management of these conditions.

RECENT FINDINGS

The GI microbiome is strongly influenced by ageing, diet and disease. Probiotics may confer health effects to the host by modulating the metabolic activities of the microbiome to propagate anti-inflammatory effects and reinforce the intestinal barrier, and are considered to be safe to use. Many short-term studies have demonstrated the effectiveness of probiotics overall in IBS, with meta-analyses demonstrating efficacy across specific strains albeit with relatively small effect sizes. Within IBD, some probiotics appear to offer clinical benefit in ulcerative colitis but strain-specific effects are unclear. Evidence for the use of probiotics in Crohn's disease remains limited.

SUMMARY

Probiotics offer considerable potential for the management of IBS and possibly in IBD, however, any benefits conferred appear to be strain-specific. High quality trials of specific probiotics in IBS and IBD, as well as laboratory investigations of their mechanism of action, are required in order to fully understand their potential therapeutic value.