Gut microbiota–host immune system axis

The gut microbiota–host immune system axis describes the ongoing, reciprocal interactions between the microorganisms populating the digestive tract and the host's immune systems, which are essential for maintaining health[1][2][3][4][6]. The gut microbiota affects maturation, education, and function of both innate and adaptive immunity, helping to regulate immune tolerance to benign commensals and to defend against pathogens. Dysregulation in this axis can contribute to a wide range of diseases, including inflammatory, metabolic, autoimmune, and neoplastic disorders. Key molecular mediators include microbial metabolites (e.g., SCFAs), immunoglobulins (e.g., secretory IgA), cytokines, and various immune cell subtypes (e.g., T cells, dendritic cells, innate lymphoid cells)[1][2][3][4][5][6]. This entry refers to a system-level concept rather than a therapeutic molecular target or receptor. For drug discovery or structured analysis, the relevant individual molecules (e.g., specific cytokine receptors, microbial enzymes) should be addressed separately.

Other names

gut microbiota–immune system interactionmicrobiota–immune axisgut-immune axis

No singular mechanism—interventions may act by altering microbiota composition, immune signaling, or barrier integrity. No direct drugs target the axis as a whole.