In a 2017 study [92], the human gastric microbiota was evaluated in the context of hypochlorhydria caused by various factors (Hp-related CAG, AAG and PPI use); this study found that patients with AAG had a higher microbial diversity compared to patients with Hp-related gastritis (specifically, samples taken from patients with AAG showed a predominance of Streptococcus). The gene discussed is HP; the disease is gastritis.