HP and gastric cancer: Differential compositions of non-Hp gastric microbiome have been reported between normal individuals, pre-malignant lesions and gastric cancer, although the data have been inconsistent concerning specific bacteria associated with the stage of gastric lesions and it is still unclear whether the observed differences in microbiota are a cause or consequence of carcinogenesis (Sheh and Fox, 2013; Aviles-Jimenez et al., 2014; Dias-Jacome et al., 2016; Alarcón et al., 2017).