Dietary Factors: Major Regulators of the Gut’s Microbiota

Dietary factors and the associated lifestyle play a major role in the pathophysiology of many diseases. Several diets, es-pecially a Western lifestyle with a high consumption of meat and carbohydrates and a low consumption of vegetables, have been linked to common diseases, such as metabolic syndrome, atherosclerosis, inflammatory bowel diseases, and colon cancer. The gastrointestinal tract harbors a com-plex and yet mainly molecularly defined microbiota, which contains an enormous number of different species. Recent advances in sequencing technologies have allowed the characterization of the human microbiome and opened the possibility to study the effect of “environmental ” factors on this microbiome. The most important environmental fac-tor is probably “what we eat, ” and the initial studies have revealed fascinating results on the interaction of nutrients with our microbiota. Whereas short-term changes in dietary patterns may not have major influences, long-term diets can affect the microbiota in a substantial manner. This issue may potentially have major relevance for human gastrointestinal health and disease because our microbiota has features to regulate many immune and metabolic functions. Increas-ing our knowledge on the interaction between nutrients and microbiota may have tremendous consequences and result in a better understanding of diseases, even beyond the gas-trointestinal tract, and finally lead to better preventive and therapeutic strategies. (Gut Liver 2012;6:411-416