Autologous fecal transplantation from a lean state potentiates caloric restriction effects on body weight and adiposity in obese mice

Autologous fecal transplantation (FT-A) emerges as a promising strategy to modulate gut microbiota with minimal side effects since individual´s own feces are transplanted. With the premise of improving obesity and its associated disorders, we investigated if fecal microbiota transplantation (FMT), heterologous and autologous, potentiates the effects of a moderate caloric restriction (CR) in high-fat diet (HFD)-induced obese mice. Mice were randomized into control, HFD, CR (12 weeks on HFD and 6 weeks under CR), FT-H (similar to CR and FMT carried out with feces from controls, weeks 17 & 18), and FT-A (administration of their own feces before developing obesity at weeks 17 & 18). Our study demonstrated that FMT, and, especially, FT-A potentiates the effects of a moderate CR on weight loss and adiposity in the short term, by decreasing feed efficiency and increasing adipose tissue lipolysis. Although FT-A produced a significant increase in bacterial richness/diversity, FMT did not significantly modify gut microbiota composition compared to the CR at phyla and bacteria genera levels, and only significant increases in Bifidobacterium and Blautia genera were observed. These results could suggest that other mechanisms different from bacterial microbiota engraftment participates in these beneficial effects. Thus, FT-A represents a very positive synergetic approach for obese patients that do not respond well to moderate restrictive diets.