Short Chain Fatty Acid Production and Glucose Responses by Methane Producers

Fermentation by gut microbiota has been linked to physiologic responses in the host. Methanogenic gut bacteria may remove more carbon from indigestible food matrices like poorly digested carbohydrates. We assessed the effects of methane production on short chain fatty acid (SCFA) concentrations in feces and glucose homeostasis. Six breath methane producers (MP) and 6 non-producers (NM) matched by gender and BMI were identified from 22 participants fed a 9-12 monomer oligosaccharide linked by 1-3 and 1-6 glycosidic bonds and terminated by a maltose group in a 3-way crossover design. Participants consumed zero, 15 or 30 g/d of the polysaccharide for 3-wk test periods separated by at least 2-wk washout periods. In the 3rd wk of each test period, for 5 successive days all stool was collected and frozen. A meal challenge using half the daily dosage of polysaccharide was conducted at the end of each test period when blood, urine and breath samples were collected. Comparisons were made between the 0 and 15 g/d doses in MP and NM. SCFA were measured by GC-MS. Blood glucose and insulin excursions were measured in response to test meals periodically on the test day. Glucose excursions were lower in MP (p