In patients undergoing gastroplasty, one study observed that before surgery patients with morbid obesity and high levels of hemoglobin A1c showed low levels of Bifidobacteria in saliva and feces, and 2 weeks after the surgery the levels of oral Bifidobacteria increased 10-fold while TNFα levels decreased, (19) although it is important to consider the influence of comorbidities involved in this relation. The gene discussed is TNF; the disease is morbid obesity.