Role of Methane in Glycemic Control

The purpose of this study is to determine how certain types of bacteria in the human gut may affect weight gain, and contribute to the development of diabetes. The investigators initial studies have shown that gut bacteria that produce methane may directly affect weight gain. These bacteria, called methanogens, produce methane gas as a byproduct, which can be detected through breath testing. Methane can slow the passage of food through the intestines, which would allow extra time for uptake and absorption of nutrients and calories, and might contribute to weight gain. The investigators have also found that people who have increased levels of methane-producing bacteria in their intestines also have higher levels of glucose in their blood. Therefore, control of how the body responds to insulin and uses glucose may be altered in methane-producing individuals. This research study is designed to test the investigational use of the drugs neomycin and rifaximin that have been approved by the U.S Food and Drug Administration (FDA). While neomycin is FDA-approved for treating skin infections, preparing the bowel for surgery, and hepatic encephalopathy (a condition that occurs when a damaged liver cannot remove the toxins that a healthy liver normally would), and rifaximin is FDA-approved for treating travelers' diarrhea, they are not yet approved to be used together for the treatment of methanogens or obesity.