Gut microbiome and host immune system

The term "gut microbiome and host immune system" refers to the complex, bidirectional interactions between the communities of microorganisms inhabiting the gastrointestinal tract (the gut microbiome) and the host’s immune system. Rather than a single molecule or receptor, this is a biological axis or system comprising trillions of microbes and a network of immune cells, tissues (including Peyer's patches and mesenteric lymph nodes), and signaling pathways[1][2][3][4][5][6][7]. The gut microbiome influences immunity by producing metabolites (such as short-chain fatty acids) that regulate inflammatory signaling and guide the development/function of both innate and adaptive immune cells. Host immunity, in turn, maintains microbiome balance through barrier defense, antibody (especially IgA) secretion, and immune tolerance mechanisms. Dysregulation of these interactions is implicated in numerous diseases—including inflammatory, autoimmune, infectious, metabolic, and neoplastic disorders. Therapeutic strategies often aim to modulate the gut microbiome or immune responses to restore health, typically using probiotics, prebiotics, antibiotics, or microbiota transplants. This is not a canonical therapeutic target (such as a receptor, enzyme, transporter, or transcription factor), but rather designates a biological interface or regulatory system that can be targeted as part of complex interventions—not as a singular target molecule. The label is therefore "incorrect" when used in the context of molecular or receptor drug targeting.

Other names

Gut microbiota-immune interactionsMicrobiota-immunity axisGut microbiota and immune crosstalk

Modulation of microbiota composition to influence immune signaling; Promotion of regulatory T cell induction; Suppression of inflammatory responses by SCFA production; Enhancement or restoration of barrier integrity