Allobaculum plays a predominant role in the activation of brown fat tissue by diallyl trisulfide

Diallyl trisulfide (DATS) is a bioactive compound in garlic. It has been reported to ameliorate obesity by preventing adipogenesis and lipogenesis in white adipose tissue. But we found DATS could also activate brown adipose tissue (BAT) in high-fat diet (HFD)-fed mice, suggesting another pathway to ameliorate obesity. To explore the mechanism of DATS activating BAT, mice fed with a HFD were treated with DATS. The results showed that DATS significantly activated BAT and regulated the gut microbiota. Next, gut microbiota transplantation (GMT) was carried out, and it was found that the effects of DATS on BAT and obesity were transferred by GMT. Further, the gut microbiota was analyzed and the bacteria that showed consistent alteration in DATS-treated mice and GMT recipient mice were screened. The results showed that Allobaculum was significantly promoted by different doses of DATS and GMT, suggesting Allobaculum may be a potential factor mediating the effects of DATS. Finally, oral supplementation of Allobaculum stercoricanis, a primary species in Allobaculum, confirmed the effects of A. stercoricanis on BAT and obesity. Additionally, the effects of live A. stercoricanis and pasteurized A. stercoricanis were compared and the results revealed that pasteurization did not diminish the beneficial effects of A. stercoricanis, which indicates inactivated bacterial cells or cellular components are responsible for the beneficial effects of A. stercoricanis. This study reveals that DATS promotes the thermogenesis of BAT by regulating gut bacterium Allobaculum and provides theoretical support for the application of DATS and A. stercoricanis in the treatment of obesity.