The role of diet composition in high-fat diet induced obesity related microbiota composition.

Evidence suggests altered gut microbiota composition may be involved in the development of obesity. Studies using mice made obese with refined high-fat diets have supported this, however these have commonly used chow as a control diet, introducing confounding factors from differences in dietary composition that have a key role in shaping microbiota composition. We compared the effects of feeding a refined high-fat diet with either a refined low-fat diet or a chow diet on gut microbiota composition and host physiology. Feeding both refined low or high fat diets resulted in large alterations in the gut microbiota composition, intestinal fermentation, and gut morphology, compared to chow. However, body weight, body fat, and glucose intolerance only increased in mice fed the refined high-fat diet. The choice of control diet can disassociate broad changes in microbiota composition from obesity raising questions about the previously proposed relationship between gut microbiota and obesity.