Figure 3.

Diet and extrinsic stressors that alter the composition of gut microbiota and are associated with intestinal inflammation A western diet reduced SCFA-producing bacteria. Environmental stressors, including heat, noise, high altitude, toxicants, and pollutants decreased Faecalibacterium, Lactobacillus, and Lachnospiraceae, while increasing Enterobacteriaceae. In addition, psychological stress reduced the proportion of Lactobacillus and Lachnospiraceae. These gut microbiota alterations may decrease mucus, SCFAs, and AMPs production, as well as tight junction protein expression, resulting in intestinal inflammation.