 (2009) identified two distinct populations of the gut bacteria "Helicobacter pylori" that accompanied human migrations into Island Southeast Asia and Oceania, called hpSahul and hspMaori.The study sampled Native Australians, Native Taiwanese, highlanders in New Guinea, and Melanesians and Polynesians in New Caledonia, which were then compared with other "H. pylori" haplotypes from Europeans, Asians, Pacific Islanders, and others.They found that hpSahul diverged from mainland Asian "H. pylori" populations approximately 31,000 to 37,000 years ago and have remained isolated for 23,000 to 32,000 years confirming the Australo-Melanesian substratum in Island Southeast Asia and New Guinea.