Obesity and the gut microbiome: pathophysiological aspects

Abstract

AbstractWhile there is a large volume of literature describing a role for obesity as a risk factor for breast cancer and many other cancers, in the main a causal relationship has not been established. If the study is limited to breast cancer risk, it has been suggested that the increase in sex steroid formation that occurs in postmenopausal women plays a role. Obesity is known to be associated with chronic low grade inflammation, but no reason for this association has been offered in the past. The gut microbiome, while known to be enormous, has not in the past been considered as a metabolic role player in the body. This is now recognized to be the case. Recent studies have found the obesity is correlated with an alteration in the gut microbiome. In obese individual there is a change in the relative proportions of the two major classes of bacteria – bacteroides and firmacutes – with the latter dominant in obesity and resulting in the formation of increased amounts of metabolic endotoxins like deoxycholic acid and lipopolysaccharides (LPS). Obese individuals show a decrease in the concentration of