NHE3-/- mice show reduced microbial diversity with expansion of the inflammation-associated Bacteroidetes phylum and contraction of the Firmicutes phylum (Engevik et al., 2013; Harrison et al., 2018), which is consistent with what has been found in IBD patients (Ott et al., 2004; Sokol and Seksik, 2010; Fava and Danese, 2011). This evidence concerns the gene SLC9A3 and inflammatory bowel disease.