The expansion of the Firmicutes phylum we observed in male Fabp6−/− mice fed the WSD at the expense of other phyla is also distinct from that of female Fabp6−/− mice fed the same diet, and this is concordant with the pattern of change known to promote obesity (Musso et al., 2011; Ridaura et al., 2013). The gene discussed is FABP6; the disease is obesity disorder.