Additional to the advantage offered to the E. coli in the ruminants’ gastro-intestinal (GI) tract, the nanS-p could also cause, as a side effect, an improved colonization of the human GI tract, rich of Neu-5,9-Ac2 (Saile et al., 2018), facilitating the insurgence of the most severe forms of the infections in humans. This evidence concerns the gene NANS and infection.