proximal jejunum to absorb glucose. The trapping of available carbohydrate within intact cell walls and alterations of the physical characteristics of the intraluminal contents by unabsorbable carbohydrates may both result in reduced availability of glucose for absorption in the proximal small bowel while increasing its availability in the distal small bowel. The adaptation of the proximal jejunum may then be reversed, resulting in a flatter glucose tolerance curve. It is possible that some diabetic patients might benefit from treatment with wheat bran or other dietary fibres and unavailable carbohydrates.