What is Gut Microbiota? Small bacterial community that inhabits the entire length of the gastrointestinal (GI) tract is known as gut microbiota. The gut microbiota is mainly composed of bacteria from two major phyla: Bacteroidetes and Firmicutes are the two major phyla that occur inside the gut but there are some less abundant phyla also present such as Actinobacteria, Proteobacteria, Euryachaeota, and Verrucomicrobia (1)(2). The density and composition of the human gut microbiota is described in Figure 1. These gut microbiotas possess numerous other metabolic abilities and activities, such as changing diet and other lifestyle factors can alter gut microbiota balance (dysbiosis) and cause increase intestinal permeability (3,(4)(5).(Figure 2) The gut microbiota also has some pathophysiological interactions with the host, particularly in the case of obesity and related metabolic disorders. The high-fat diet has also been shown to increase in gut permeability, which facilitate translocation of luminal content to the inner layers of the intestinal wall and induce inflammation (6). Not only diet but several bacteria can have impact on intestinal permeability. For example, some pathogenic genus of bacteria depletes gut barrier while some commensal bacteria work as a probiotic and promote the intestinal barrier. This review will be a critical review of the literature that has identified the role of the specific gut microbiota on intestinal permeability in obesity.
2: Gut microbes in Obesity/Insulin Resistant. Obesity is a major risk factor for metabolic diseases such as cardiovascular disease and diabetes (7). The development of obesity is due to an excess of energy intake compared to energy expenditure. Studies show that the gut microbiota and its collective genome are altered in obesity (7)(8)(9). But, another study published by Jumpertz et al. showed the pyrosequencing result of 16S rRNA genes from gut bacteria and observed no difference at phylum level between the obese and lean fecal microbiota (10)(11). This demonstrates that there are not consistent shifts in the gut microbiota between lean and obese individuals.