Gastrointestinal microbiota and mucosal immune system (Gut-immune axis)

The gastrointestinal microbiota and mucosal immune system constitute a dynamic and reciprocal interface essential for maintaining host homeostasis. The gut microbiota, comprising trillions of bacteria, fungi, and viruses, provides critical signals that drive the maturation and regulation of the mucosal immune system, which contains the majority of the body's effector lymphoid cells (Belkaid & Hand, 2014). This interaction is mediated through microbial metabolites, such as short-chain fatty acids (SCFAs), and structural components like lipopolysaccharides that interact with host pattern recognition receptors (Round & Mazmanian, 2009). When this balance is disrupted, a state of dysbiosis occurs, which is strongly associated with the pathogenesis of inflammatory bowel disease, metabolic syndrome, and various autoimmune conditions. Therapeutic strategies targeting this system include fecal microbiota transplantation (FMT), probiotics, and prebiotics, which aim to restore microbial diversity and promote immune tolerance (FDA, 2023). Understanding this axis is pivotal for developing precision medicine approaches that leverage the microbiome to modulate systemic immunity. Recent advancements have led to the approval of microbiota-based therapies for recurrent infections, highlighting the clinical relevance of this system. Future research continues to explore how specific microbial strains can be used to fine-tune immune responses in oncology and chronic inflammatory diseases.

Other names

Gut microbiota-immune system axisIntestinal microbiota-mucosal immunityMicrobiome-immune interfaceGut-immune system crosstalk

Modulation of microbial composition to restore diversity, production of immunomodulatory metabolites like short-chain fatty acids (SCFAs), induction of regulatory T cells (Tregs) to promote tolerance, and enhancement of the intestinal epithelial barrier to prevent translocation of pathogens (Belkaid & Hand, 2014; Round & Mazmanian, 2009).