Short-Chain Fatty Acids as Bacterial Enterocytes and Therapeutic Target in Diabetes Mellitus Type 2

Abstract

Diabetes mellitus is a disease with multiple gastrointestinal symptoms (diarrhea or constipation, abdominal pain, bloating) whose pathogenesis is multifactorial. The most important of these factors is the enteric nervous system, also known as the "second brain"; a part of the peripheral nervous system capable of functioning independently of the central nervous system. Modulation of the enteric nervous system can be done by short-chain fatty acids, which are bacterial metabolites of the intestinal microbiota. In addition, these acids provide multiple benefits in diabetes, particularly by stimulating glucagon-like peptide 1 and insulin secretion. However, it is not clear what type of nutraceuticals (probiotics, prebiotics, and alimentary supplements) can be used to increase the amount of short-chain fatty acids and achieve the beneficial effects in diabetes. Thus, even if several studies demonstrate that the gut microbiota modulates the activity of the ENS, and thus, may have a positive effect in diabetes, further studies are needed to underline this effect. This review outlines the most recent data regarding the involvement of SCFAs as a disease modifying agent in diabetes mellitus type 2. For an in-depth understanding of the modulation of gut dysbiosis with SCFAs in diabetes, we provide an overview of the interplay between gut microbiota and ENS.

Keywords: diabetes mellitus; enteric nervous system; glucagon-like peptide 1; gut microbiota; short-chain fatty acids.

Figure 1

The organization of gut wall layers.

Figure 2

Common pathways shared between gut microbiota and Enteric Nervous System. Abbreviations: CB1, cannabinoid receptor 1; ChAT+, Choline acetyltransferase; DRG, dorsal root ganglia; SCFAs, 5-HT4, 5-Hydroxytryptamine receptor 4; MAMP, microbe-associated molecular pattern; MOR, mu-opioid receptors; NGF, nerve growth factor; nNOS+, Neuronal nitric oxides synthase; SCFAs, Short-chain fatty acids; TLRs, Toll-like receptors.