Probiotics and Their Metabolites Ameliorate Inflammatory Bowel Disease: A Critical Review

Abstract. Crohn disease and ulcerative colitis are the two main manifestations of inflammatory bowel disease (IBD), and both are highly morbid. However, the precise etiology of IBD is still unknown and effective therapeutics are yet to be discovered. It is becoming increasingly clear that a combination of factors, including genetic background, host immune response, and microbial reduced diversity status are related to IBD. The cardinal symptom of IBD patients is the imbalance of the intestinal microflora. According to previous studies, both probiotics and symbiotic microbiota can play a protective role through intestinal micro-ecosystem regulation, epithelial barrier integrity enhancement, and inflammation reduction. Therefore, probiotics can provide an alternative or auxiliary method to traditional IBD treatment. Here, we reviewed the possible pathogenesis of IBD, summarized the possible mechanisms of probiotics modulation of IBD, and emphasized the prevention and treatment targets of probiotics-mediated IBD, with the aim to provide theoretical support for the treatment of IBD patients by probiotics in clinical trials.