The objectives of this study are to examine the effects of ethnicity, gender, and proton pump
inhibitor (PPI, omeprazole), on the human gut microbiome. The investigators hypothesize that
PPI therapy might perturb microbial communities and alter the gut microbiome. Young, healthy
subjects of Chinese, Malay and Indian ancestry, were enrolled. They were required to provide
a baseline stool sample (Day 1) and were then given a course of omeprazole at therapeutic
dose (20 mg daily) for a duration of 7 days. Stool samples were collected again on Day 7 and
Day 14 (one week after stopping omeprazole). The DNA samples were subjected to 16S ribosomal
ribonucleic acid (rRNA) sequencing.