Intestinal barrier and gut microbiota: Shaping our immune responses throughout life

ABSTRACT

The gastrointestinal (GI) tract is considered the largest immunological organ in the body having a central role in regulating immune homeostasis. Contrary to earlier belief, the intestinal epithelial barrier is not a static physical barrier but rather strongly interacts with the gut microbiome and cells of the immune system. This intense communication between epithelial cells, immune cells and microbiome will shape specific immune responses to antigens, balancing tolerance and effector immune functions. Recent studies indicate that composition of the gut microbiome affects immune system development and modulates immune mediators, which in turn affect the intestinal barrier. Moreover, dysbiosis may favor intestinal barrier disruption and could be related to increased susceptibility to certain diseases. This review will be focused on the development of the intestinal barrier and its function in host immune defense and how gut microbiome composition throughout life can affect this role.

KEYWORDS:

• ageing
• development
• gut immunity
• microbiota
• mucosal barriers

Disclosure of potential conflicts of interest

No potential conflicts of interest were disclosed.

Acknowledgments

We thank Prof. Dr. Shaker Chuck Farah (Department of Biochemistry, Institute of Chemistry, University of Sao Paulo) for his constructive reading and comments. We also thank the CAPES-PNPD program for the postdoctoral fellowship of Dr. Tatiana Takiishi, and FAPESP for the doctoral fellowship of Camila Ideli Morales Fénero.