While it has been well established that the gastrointestinal microbiota plays a role in the regulation of host metabolism, little is known about the connections between the composition of the gut microbiota and its effect on host metabolic pathways and processes. This is a valuable area of research, as changes in the host gut flora have been linked to various health problems. This knowledge calls for a better understanding of the bacterial patterns and functions associated with and contributing to these health problems.
In a recent study, researchers added plant sterol esters to the diets of hamsters and proceeded to characterize their fecal microbiota. The dietary changes influence the composition of the gut microbiota in hamsters, and ultimately alter their metabolic function. Hamsters were chosen for the study due to their lipid profiles, enzymatic pathways in lipoprotein and in bile metabolism, which are similar to that of humans. Hamsters are also similarly susceptible to diet induced atherosclerosis. The addition of the plant sterol esters inhibited several bacterial taxa within the families Coriobacteriaceae and Erysipelotrichaceae. The addition of plant sterol esters causes a gut microbe community shift by blocking intestinal cholesterol absorbance, this, in turn, decreases cholesterol levels in the liver and plasma. The decreased plasma and liver cholesterol levels prompts increased cholesterol excretion in the gut. These increased cholesterol levels appear to inhibit bacterial taxa of the mentioned families.
Though the evidence presented in this study is not sufficient to assert a cause-effect relationship, the results of the study does indicate an association between dietary changes, alterations in the gut microbiota, and changes in host cholesterol metabolism.