Microbiota–host immune axis

The microbiota–host immune axis is a complex, bidirectional communication system between the human microbiome and the host's innate and adaptive immune systems [1, 6]. It plays a critical role in maintaining physiological homeostasis by training the immune system to tolerate commensal microbes while responding to pathogens [1, 7]. This interaction is mediated through various mechanisms, including the recognition of microbial-associated molecular patterns (MAMPs) by pattern recognition receptors (PRRs) like Toll-like receptors (TLRs) and the production of immunomodulatory metabolites such as short-chain fatty acids (SCFAs) [1, 4, 14]. Dysregulation of this axis, known as dysbiosis, is implicated in the pathogenesis of numerous diseases, including inflammatory bowel disease (IBD), allergies, metabolic syndromes, and neurodegenerative conditions [1, 5, 11]. Therapeutic interventions targeting this axis, such as probiotics, prebiotics, and fecal microbiota transplantation (FMT), aim to restore microbial balance and modulate host immune responses to treat or prevent disease [1, 11, 12]. Additionally, the composition of the microbiota can significantly influence the efficacy and toxicity of other therapies, such as immune checkpoint inhibitors in cancer treatment [8, 12]. Emerging research also highlights the role of the axis in the gut-brain connection, influencing neuroinflammation and behavior [9, 11]. Understanding the molecular crosstalk within this axis is essential for the development of precision medicine approaches that leverage the microbiome for therapeutic benefit [1, 2].

Other names

Host-microbiota-immune axisMicrobiome-immune axisGut microbiota-immune axisHost-microbe immunological axis

Modulation of microbial composition and metabolite production to regulate innate and adaptive immune signaling pathways, including the activation of pattern recognition receptors and the induction of regulatory T cells.