Crosstalk Among Gut Microbiota, Microbial Metabolites, and Inflammatory Cytokines: Current Understanding and Future Directions

The interaction between the gut microbiota and the host immune system is pivotal in maintaining health or driving disease pathogenesis. The gut microbiota directly or indirectly modulates immune cells activation and inflammatory cytokines secretion through microbial metabolites, including short-chain fatty acids (SCFAs), tryptophan metabolites, bile acids, and polyamines. Conversely, the immune system regulates microbial community composition by maintaining the integrity of the epithelial barrier. In addition, antibiotics and probiotics can further regulate the inflammatory response by altering gut microbiota structure and microbial metabolites levels. This review systematically examines the bidirectional regulatory mechanisms among the gut microbiota, microbial metabolites, and inflammatory cytokines, and explores the impact of antibiotics and probiotics on this interaction network. These insights provide new targets for immune-related diseases.