Intestinal microbiota and its relationship to obesity in mouse model

Abstract

The gut microbiota contributes to host body weight regulation by influencing calorie harvest from dietary components. The present study aimed to determine the influence of different diets on body composition in germ free (GF) mice and on intestinal microbiota composition in conventional (CV) mice. Twelve week old GF and CV male C3H mice were fed either a standard chow diet (SD), a semi-synthetic low fat diet (LFD), a semi­ synthetic a high fat diet (HFD), or a commercial Western diet (WD). GF and CV mice on the LFD did not differ in body weight

gam and body fat mass. GF mice on the HFD gained significantly more body weight and body fat than their CV counterparts. The gut microbiota composition of CV mice differed in response to the different diets. On both the HFD and the WD, the mice had a larger proportion of Firmicutes m conjunction with a smaller proportion of Bacteriodetes as compared to the mice received SD. The higher proportion of Firmicutes was due to the proliferation of one family within this

phylum: the Erysipelotrichaceae. There was no difference in faecal short chain fatty acid (SCFAs) concentrations between CV mice on either of the high-fat diets (HFD and WD). These results led to the conclusions that the absence of gut microbiota does not protect the mice from diet-induced obesity, that the SCFAs were not the main cause of body weight gain in CV mice fed the high-fat diets, and that diet composition has a bigger influence on gut microbial composition than previously thought.