FAAH and obesity due to melanocortin 4 receptor deficiency: Perhaps more interestingly, inhibition of endocannabinoid signaling has been shown to be accompanied by increased Ruminococcaceae abundance in the context of obesity (Chen et al., 2020), possibly in agreement with our present finding that OlAla, a mediator possibly acting in part by elevating endocannabinoid levels via FAAH inhibition, instead produces the opposite effect on Ruminococcaceae-UCG 005.