Gastrointestinal adaptation following small bowel bypass for obesity.
Small intestinal morphologic and biochemical changes were studied following jejuno-ileal bypass for obesity after body weight stabilization had occurred. Four patients underwent biopsy of in-continuity and bypassed jejunal and ileal segments of the small intestine 11 to 22 months after the bypass operation. Microscopically, marked mucosal villus hypertrophy of the in-continuity bowel was observed, especially in the ileum. Bypassed jejunal mucosa underwent atrophy compared with pre-bypass jejunum, whereas bypassed ileum appeared similar microscopically to pre-bypass ileum. The specific activities of mucosal disaccharidase enzymes (maltase, sucrase, lactase and trehalase) in units per mg protein remained similar to pre-bypass levels in segments of the in-continuity jejunum and the bypassed jejunum and ileum. On the other hand, elevated mucosal disaccharidase levels were measured in biopsy specimens of the in-continuity ileum. Total enzyme activity per unit length of intestine, however, was estimated to be elevated in both in-continuity jejunum and ileum secondary to mucosal villus hypertrophy. These data indicate that following small bowel bypass: (1) the in-continuity ileum undergoes greater biochemical and morphologic adaptation than the jejunum; and (2) intraluminal nutrients and chyme appear to be essential to maximal intestinal adaptation.
D000222:Adaptation, Physiological; D000328:Adult; D001707:Biopsy, Needle; D004186:Disaccharidases / Q000378:metabolism; D005260:Female; D006801:Humans; D007082:Ileum / Q000201:enzymology / Q000473:pathology / Q000601:surgery*; D007413:Intestinal Mucosa / Q000201:enzymology* / Q000473:pathology*; D007583:Jejunum / Q000201:enzymology / Q000473:pathology / Q000601:surgery*; D008099:Liver / Q000473:pathology; D009765:Obesity / Q000628:therapy*
D004186:Disaccharidases