Dietary Uncoupling of Gut Microbiota and Energy Harvesting from Obesity and Glucose Tolerance in Mice

Abstract

Evidence suggests that 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 those of feeding 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 a chow diet. However, body weight, body fat, and glucose intolerance only increased in mice fed the refined high-fat diet. The choice of control diet can dissociate broad changes in microbiota composition from obesity, raising questions about the previously proposed relationship between gut microbiota and obesity. Dalby et al. show that high-fat-diet-induced changes in gut microbiota composition and cecal fermentation can be dissociated from obesity and glucose intolerance in mice by using a nutritionally more appropriate control diet. This highlights the importance of the control diet in interpreting microbiota studies.