The two variables representing gastrointestinal phenotypes (gastroesophageal reflux disease [GERD] and drugs for peptic ulcers and GERD) had the most associations, with 24 and 27 OTUs respectively, followed by anxiolytics (anti-anxiety drugs) with 27, analgesics (pain killers) with 23, estrogens with 21, and insulin and hypoglycemic drugs with 18 associated OTUs. The gene discussed is INS; the disease is gastroesophageal reflux disease.