A Review on the Molecular Dynamics of Enterotype Bacteroides 2 in Relation to Inflammatory Bowel Disease

Bacteroides 2 (Bact2) is a dysbiotic enterotype often associated with susceptibility to developing diseases such as inflammatory bowel disease (IBD). Carriers of Bact2 are found to be less responsive to therapeutic treatments like vedolizumab. This enterotype is characterised by a large amount of Bacteroides, low diversity in bacteria, fewer butyrate-producing species, and generally a low abundance of microbes in the gut. However, it remains unclear whether this dysbiosis contributes to IBD pathology or if it is merely a result of inflammation in the gut. Due to its ability to influence treatment responses, it is crucial to understand the molecular mechanisms behind this enterotype, as well as the effect of diet on this dysbiosis. A high concentration of pro-inflammatory cytokine IL-1$\beta$ was found in the faecal water of Bact2 patients, as well as an abundance of conjugated bile acids, whereas butyrate was found in decreased amounts. Through the consumption of a less industrialised diet, it could be possible to shift away from a dysbiotic enterotype like Bact2. This includes the consumption of whole-grain carbohydrates to increase the growth of butyrate-producers and maintaining a low-fat diet to decrease bile acid production.