MUC2 deficient mice possessed an “obesity-like” increase in the F:B ratio, depletion of two probiotics, Lactobacilli and Lachnospiraceae, enrichment in potential pathobionts, Erysipelotrichaceae and Desulfovibrio and elevated α-diversity, the latter being a common occurrence in MUC2 deficient mice with colorectal cancer development (Lu et al., 2016). This evidence concerns the gene MUC2 and obesity due to melanocortin 4 receptor deficiency.