Pinart et al. (2021) identified 15 bacterial genera whose relative abundance is altered in obesity, and it is well established that the gut microbiome influences energy harvesting, fat storage, inflammation, appetite regulation, and insulin sensitivity in the context of obesity (Bäckhed et al., 2004; Musso et al., 2010; Tilg and Kaser, 2011; Turnbaugh et al., 2006). This evidence concerns the gene INS and obesity due to melanocortin 4 receptor deficiency.