Going with his gut bacteria.
Wenner
Melinda
M
D001419:Bacteria / Q000378:metabolism*; D015415:Biomarkers / Q000032:analysis / Q000097:blood / Q000652:urine; D001944:Breath Tests; D005243:Feces / Q000737:chemistry; D006304:Health Status; D016480:Helicobacter pylori / Q000378:metabolism; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D008660:Metabolism
D015415:Biomarkers