 Previous studies from the investigators group and beyond have demonstrated that L cells, the prime enteroendocrince cells EECs secreting GLP-1, directly sense glucose uptake and have receptors for bile acids and short chain free fatty acids bacterial fermentation products of carbohydrates. Each of these pathways could theoretically contribute to the enteroendocrine detection of ingested carbohydrate, but the relative importance of the different sensory mechanisms before, as well as after, GI surgery is unknown. 