Gut microbiota-host innate immune system axis

The gut microbiota and host innate immune system constitute a complex, bidirectional communication axis essential for maintaining physiological homeostasis and immune tolerance (Belkaid & Hand, 2014, Science). The innate immune system utilizes pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) and NOD-like receptors (NLRs), to sense microbe-associated molecular patterns (MAMPs) and metabolites like short-chain fatty acids (SCFAs) produced by commensal bacteria (Hooper et al., 2012, Science). This interaction is critical for the maturation of immune cells, the maintenance of the intestinal epithelial barrier, and the prevention of pathogen colonization (Thaiss et al., 2016, Nature). Dysregulation of this axis, often termed dysbiosis, is linked to a wide range of pathologies, including inflammatory bowel disease (IBD), obesity, and autoimmune disorders (Zheng et al., 2020, Cell Research). Therapeutic strategies targeting this system include the use of probiotics, prebiotics, and fecal microbiota transplants to restore a healthy microbial balance and modulate host immune signaling (Cani, 2018, Gut). Because this entry describes a broad physiological interaction involving numerous distinct proteins and organisms rather than a single molecular entity, it is classified as a biological system or axis.

Other names

Gut-immune axisMicrobiome-innate immunity crosstalkCommensal-host immune interactionGut microbiota-host immune system interface

Modulation of the intestinal microbial ecosystem and its metabolic byproducts to regulate host innate immune signaling via pattern recognition receptors (PRRs) and maintain epithelial barrier integrity (Belkaid & Hand, 2014, Science; Cani, 2018, Gut).