A remarkable microbiota change was seen in controls and those with cirrhosis after omeprazole (QIIME P < 0.0001). Streptococcaceae abundance, normally found in increased quantity in saliva, significantly increased after omeprazole in controls (1 vs. 5%) and cirrhosis (0 vs. 9%) and was correlated with serum gastrin levels (r = 0.4, P = 0.005). The gene discussed is GAST; the disease is Cirrhosis.