Comparison of the amount of pectin in the human terminal ileum with the amount of orally administered pectin

Abstract

Objective Dietary fiber by definition is resistant to digestion and absorption in the human small intestine, and it should naturally reach the large intestine. To date, there have been several reports that have examined in vivo how much dietary fiber actually reaches the terminal ileum in human subjects using glucose, with large differences in results. We compared the amount of pectin in the human terminal ileum with that of orally administered pectin. Methods Seven healthy male volunteers ages 20 to 27 y were given a test meal containing 4.05 g of pectin. A double-lumen tube was placed in the terminal ileum by using the endoscopic retrograde bowel insertion method, and the ileal contents were aspirated through the tube. Amounts of pectin orally administered and collected from the terminal ileum were estimated as galacturonic acid concentrations (Englyst’s method) and were compared with each other. Results The mean ± standard deviation amount of pectin collected in the terminal ileum was 3.58 ± 0.43 g, or 88.4 ± 10.5% of pectin administered. Further, there were large individual differences in recovery, ranging from 76.8% to 105.1%. Conclusions Approximately 90% of ingested pectin was recovered in the terminal ileum in this study. Ten percent may have been degraded by bacteria within the digestive tract, especially the terminal ileum.