THE LINK BETWEEN THE MICROBIOME AND THE IMMUNE RESPONSE

Kempuraj D. The link between the microbiome and the immune response. International Journal of Infection. 2019;3(3):104-110

D. Kempuraj^*

Department of Neurology and the Center for Translational Neuroscience, School of Medicine, University of Missouri, Columbia, USA.

*Correspondence to:
Duraisamy Kempuraj,
Department of Neurology and the Center for Translational Neuroscience,
School of Medicine,
University of Missouri,
Columbia, MO 65212, USA.

ABSTRACT

The intestinal microbiota is a large symbiotic ecosystem with the host, which plays an important role in maintaining intestinal homeostasis. The commensal microbiota regulates the maturation of the immune system of the gastrointestinal mucosa. Dysbiosis is the alteration of the biological balance between the commensal and pathogenic microbiome. Therefore, the gut microbiota is regulated by the immune system and its alteration leads to physiological dysfunction. In the intestine, innate and adaptive immunity interact with the microbiota to contribute to intestinal homeostasis and provide a mutually beneficial relationship. The immune system helps to maintain a stable microbiota and exerts an inflammatory response against pathogens. The microbiota is crucial for the development of the immune system that would remain immature without these microorganisms. Microbes and their components activate Toll-like receptors (TLRs), a type of pattern recognition receptor (PRR) that are crucial for initiating the innate immune response by activating NF-κB and leading to the induction of cytokines. Short-chain fatty acids (SCFA) such as butyrate, acetate and propionate support the intestinal barrier, decrease inflammation, stimulate T regulatory cells (Tregs) and modulate macrophages and dendritic cells. For these reasons, the balance between microbiota and the immune system is important to maintain the health of mammals.

KEYWORDS: Microbiome, microbiota, immune system, gut, intestinal homeostasis