Intestinal Ecosystem and Gut-Associated Immune System

The **intestinal ecosystem and gut-associated immune system** comprise both the community of microorganisms inhabiting the gastrointestinal tract (the microbiota) and the structured immune cells and tissues associated with the gut (such as gut-associated lymphoid tissue, dendritic cells, macrophages, and various lymphocyte populations)[1][2][3][7]. This integrated system plays a pivotal role in immune training, barrier maintenance, tolerance to harmless microbes, defense against pathogens, and the modulation of local and systemic inflammation[1][2]. Disruption of these interactions—through dysbiosis, immune dysfunction, or physical damage—can contribute to the development of inflammatory, infectious, autoimmune, and metabolic diseases[7]. The system is not a singular molecular target, but rather the subject of therapeutic approaches targeting its components or their interactions (e.g., manipulation of microbiota via drugs, diet, or transplant)[2][4].

Other names

Gut microbiome and immune systemgut-mucosal immunityintestinal immune homeostasisgut-associated lymphoid tissue (GALT)mucosal immune system

Modulation of microbial composition and diversity Promotion or inhibition of inflammatory pathways Enhancement of mucosal barrier function Regulation/differentiation of immune cell subsets (e.g., Tregs, Th17)