Gut microbiota and immunity relevance in eubiosis and dysbiosis

Human gut is colonized by numerous microorganisms, in which bacteria present the highest proportion of this colonization that live in a symbiotic relationship with the host. This microbial collection is com-monly known as the microbiota. The gut microbiota can mediate gut epithelial and immune cells inter-action through vitamins synthesis or metabolic products. The microbiota plays a vital role in growth and development of the main components of human's adaptive and innate immune system, while the immune system regulates host-microbe symbiosis. On the other hand, negative alteration in gut micro-biota composition or gut dysbiosis, can disturb immune responses. This review highlights the gut microbiota-immune system cross-talk in both eubiosis and dysbiosis. (c) 2021 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The human gut is colonized by a large number of microorganisms, primarily bacteria, which have a symbiotic relationship with the host. This microbial collection, known as the microbiota, interacts with gut epithelial and immune cells through vitamin synthesis or metabolic products. The gut microbiota plays a vital role in the growth and development of both adaptive and innate immune systems in humans, while the immune system helps regulate host-microbe symbiosis. However, disturbances in the composition of the gut microbiota, known as gut dysbiosis, can disrupt immune responses. This review focuses on the interaction between the gut microbiota and the immune system in both normal and dysbiotic states.