In this thesis, we explored the relationship between gut microbiota and host metabolism, focusing on finding an explanation for the discrepancies observed in studies assessing the effect of microbiota depletion on adipose tissue browning. We identified three factors influencing these outcomes, namely the diet, duration of the antibiotic treatment, and the housing temperature.

We demonstrated that 7-weeks of antibiotic treatment constantly induces browning of subcutaneous adipose tissue and that the amplitude of the browning was affected by additional factors such as the type of diet and the environmental conditions.

However, shorter treatment duration only promoted browning in mice fed with an animal-based diet. We also identified the housing temperature as a key factor influencing the outcome of the experiments, as the lower housing temperature-induced increase in the basal browning of the control mice masked the effect of antibiotic treatment on the browning phenotype.

Altogether, these results highlight a complex interplay between external factors and adipose tissue plasticity in response to microbiota depletion, providing new insights into the potential modulation of white adipose tissue browning for therapeutical purposes.