The effect of citrus pectin on the absorption of nutrients in the small intestine.

The extent of hydrolysis of citrus pectin in the stomach and small intestine was studied by in vivo digestion in ileostomy patients. The effect of citrus pectin on ileostomy losses of fat, nitrogen, starch, sodium and potassium was also investigated as was its effect on the absorption of phosphorus, calcium, magnesium, zinc and iron. Six ileostomy patients were studied during 10 d while on a constant low-fibre diet supplemented with 15 g citrus pectin/d on days 5, 6 and 7. The constituents mentioned in (1) as well as neutral polysaccharides, uronic acids and Klason lignin were determined in the ileostomy contents and duplicate portions of the diet. Of the uronic acids derived from the citrus pectin 70-100 per cent was recovered in the ileostomy contents. The wet weight of ileostomy fluid increased by 314 g/24 h and dry weight by 24 g/24 h after consumption of 15 g citrus pectin. During the pectin period there was a significant increase in the amount of nitrogen, fat, ash, Na and K found in ileostomy contents, while the amount of starch was unchanged. During the pectin period the apparent absorption of Fe decreased significantly, while that of P, Ca, Mg and Zn remained unchanged. It is concluded that there is only limited digestion of citrus pectin in the stomach and small intestine. The slight increase in ileal output of nitrogen may either be due to decreased digestion and absorption of fat is more pronounced. In the 3-d study addition of 15 g pectin to the diet did not seem to impair the apparent mineral absorption from the small intestine except in the case of Fe.