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Background: The activity of most intestinal nutrient transporters is adaptively regulated by the type and amounts of nutrients entering the intestinal lumen. The concentration and activity of the intestinal Na+/glucose cotransporter (SGLT1) are regulated by dietary sugars in most animal species. The activity and abundance of SGLT1 in biopsy specimens removed from human jejunal regions exposed to, and having limited access to, luminal nutrients have been measured and compared., Aims: To study the effects of luminal nutrients on the expression of SGLT1 in the human intestine., Patient and Methods: Brush border membrane vesicles (BBMV) were prepared from biopsy specimens removed from the intestine of a 50 year old man who had developed a high output jejunal fistula, and adjacent mucosal fistula, a condition present for 12 months after surgery for a strangulated hernia. BBMV prepared from intestine exposed to luminal nutrients, and from dysfunctional intestine with a limited exposure to nutrients, were used to measure Na+ dependent glucose transport and abundance of SGLT1 protein., Results: The levels of SGLT1 activity and abundance in the BBMV prepared from control biopsy specimens were similar to those found in BBMV prepared from the intestine of healthy individuals. BBMV from the dysfunctional intestine, exposed to limited levels of luminal nutrients, had reduced levels of SGLT1 activity. This reduction in SGLT1 activity and abundance was above that associated with any villus atrophy, as assessed by the abundance/activity of lactase and villin concentrations., Conclusions: These data indicate that the activity and expression of SGLT1 in human intestine is maintained by the presence of luminal nutrients.

Twenty of 81 patients treated by restorative proctocolectomy for presumed ulcerative colitis had some features of Crohn's disease: 10 were classified as definite Crohn's disease and 10 as indeterminate colitis. These pathological features were first apparent during synchronous colectomy and pouch construction in 10 of 11 cases. In the remainder, histological features of possible Crohn's disease were first identified during rectal excision (n = 6), preliminary subtotal colectomy (n = 2), and after pouch excision (= 2). Complications were marginally more common in patients with features of possible Crohn's disease: pelvic sepsis 30% (Crohn's disease 30%, indeterminate colitis 30%) v 20%, fistulas 45% (Crohn's disease 30%, indeterminate colitis 60%) v 16%; ileal stenosis 40% (Crohn's disease 40%, indeterminate colitis 40%) v 21%, pouchitis 50% (Crohn's disease 50%, indeterminate colitis 50%) v 26%, and small bowel obstruction 25% (Crohn's disease 30%, indeterminate colitis 30%) v 13%. Pouch excision or a persistent proximal stoma has been necessary in six patients with possible Crohn's disease (30%) (Crohn's disease 3 cases 30%, indeterminate colitis 3 cases 30%) compared with nine (15%) of the remainder. Median hospital stay, however, was the same and stool frequency in those with a functioning pouch were comparable. These results show that there is a higher complication rate if there are features of Crohn's disease but that the medium term functional results are acceptable if the pouch can be retained.

A method that allows the quantitative assessment of ileal mucosal cell uptake and transport of bile acids in mucosal biopsy specimens has been validated. Viability of the tissue was confirmed by maintenance of normal cell morphology, wet weight, extracellular space, porosity to polyethylene glycol-900, lactate dehydrogenase release, and transmucosal potential difference. Using 14C-taurocholic acid, absorption was shown to be directional, capable of working against a concentration gradient, reduced by metabolic inhibitors, and sodium dependent. The system showed saturation kinetics with an estimated Km of 10 mumol/l. At a standard substrate concentration of 10 mumol/l ileal mucosal bile acid absorption was compared in patients with colorectal cancer (n = 6), ulcerative colitis (n = 10), and slow transit constipation (n = 8). There was no significant difference in tissue uptake or transport between the three groups.