Systemic Immunoregulatory Consequences of Gut Commensal Translocation

One major determinant of systemic immunity during homeostasis and in certain complex multifactorial diseases (e.g. cancer and autoimmune conditions), is the gut microbiota. These commensals can shape systemic immune responses via translocation of metabolites, microbial cell wall components, and viable microbes. In the last few years, bacterial translocation has revealed itself as playing a key, and potentially causal role in mediating immunomodulatory processes in nongastrointestinal diseases. Moreover, recent observations regarding the presence of complex microbial communities and viable bacteria within gut-distal tissues during homeostasis challenge the current paradigm that healthy mammals are entirely sterile at nonmucosal sites. This review discusses our current understanding of how the gut microbiota orchestrates systemic immunity during noninfectious extraintestinal diseases and homeostasis, focusing on the translocation of viable bacteria to gut-distal sites.

Automated summary

The gut microbiota plays a crucial role in systemic immunity during homeostasis and certain complex diseases, influencing immune responses through translocation. Bacterial translocation is emerging as a key player in immunomodulatory processes in non-gastrointestinal diseases.