Role of Methane in Glycemic Control

Pre-diabetes is defined by impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) and affects more than 40% of US adults. While glycemic dysregulation and insulin resistance are central to the progression from pre-diabetes to diabetes, obesity also plays a key role. Research has begun to define the relationship between gut flora, metabolism and weight gain. Animal studies have linked a specific methanogen, Methanobrevibacter smithii, to weight gain, and in humans we have found that increased methane on breath test is associated both with increased body mass index (BMI) and higher blood glucose levels. We also found that methane gas directly slows gut transit by 59% in an in vivo animal model. We hypothesize that this slowing of transit could result in a greater time to harvest nutrients and absorb calories, representing a potential mechanism for elevated post-prandial glycemic excursions and weight gain. In this study, we will test this hypothesis by determining the effects of enteric methane production on glucose excursions, gut transit and energy utilization in obese or overweight, prediabetic, adult subjects. We will explore the relationship between methane, M. smithii, obesity and gut transit in human subjects using objective measures of metabolic function, glucose excursions, energy utilization and transit studies, to evaluate whether intestinal methane production is associated with a higher incidence of diabetes risk in an obese study population. We will then repeat testing following a course of antibiotics known to eliminate methanogens. This will potentially provide novel therapies for the pre-diabetic patient, and allow new avenues for research.