Fate of β-cyclodextrin in the human intestine

We assessed the fate of β-cyclodextrin, which is composed of seven α(1→4)-linked glucose units in ring structure, in the human gastrointestinal tract. In four healthy ileostomists, ileal effluent was collected after oral administration of β-cyclodextrin during fasting (10 g of β-cyclodextrin) and postprandially (10 g of β-cyclodextrin three times daily with meals). In 10 healthy volunteers, the amount of β-cyclodextrin passing into the colon was determined by means of the breath hydrogen technique using lactulose as a standard, and stools were collected after oral administration of β-cyclodextrin during fasting (10 g of β-cyclodextrin) and postprandially (10 g of β-cyclodextrin three times daily with meals). In ileostomists, we recovered from the small intestine 91 ± 5% and 97 ± 10% (mean ± SD) of β-cyclodextrin ingested during fasting and with meals, respectively. In healthy volunteers, H2 excretion in breath after β- cyclodextrin ingestion was low compared with excretion after lactulose, but only traces of β-cyclodextrin were recovered in stools. We conclude that β- cyclodextrin is poorly hydrolyzed in the human small intestine but that it is fermented by the colonic flora with apparent minimal H2 production.