QUALITATIVE CHANGES IN ENTERIC FLORA AND SHORT-CHAIN FATTY-ACIDS AFTER INTESTINAL RESECTION

Our aim was to determine the effect of intestinal transection and rese ction on the prevalence of enteric flora and evaluate whether any such changes alter luminal SOFA and lactic acid content. Dogs underwent ei ther 50% proximal (PR, N = 6) or distal (DR, N = 7) resection, distal resection with bypass of the ileocecal junction (DRBP, N = 9) or midpo int transection alone performed to serve as the appropriate control fo r luminal sampling for either proximal (PTC, N = 6) or distal (DTC, N = 7) resection. Studies were performed every four weeks for 12 weeks. Both jejunum and ileum had >10(5)/ml aerobic bacteria, most commonly E , coli. Streptococcal species were more common in the normal jejunum t han ileum but were found in the ileal remnant after PR. Significant (> 10(5)) anaerobic growth occurred infrequently in the jejunum, and DR d id not increase anaerobic growth in jejunum unless DRBP was performed (93% vs 62% DR, 45% DTC, 20% normal jejunum, P < 0.05). Clostridium sp ecies increased significantly in the jejunal remnant after DRBP. Signi ficant anaerobic growth occurred infrequently in normal ileum but incr eased after PR (89% vs 50% PTC, P < 0.05). Flora normally found in the jejunum tended to increase in the ileum after PR. Jejunal SCFA increa sed after DRBP (3126 +/- 577 mu g/ml vs 1600 +/- 301 DTC, P < 0.05) bu t not DR (1791 +/- 321 mu g/ml). Significant (>10(5)) anaerobic bacter ial growth was associated with increased SCFA content (2717 +/- 381 vs 1029 +/- 170 mu g/ml, P < 0.05) and the presence of lactic acid (30% vs 5%, P < 0.05), but there was no correlation between the presence of specific bacteria and SCFA and lactic acid. Following resection of th e proximal small intestine, the intestinal remnant tends to assume the bacteriologic characteristics of the resected segment. Following a di stal resection, the presence of an intact ICJ protects against the pro liferation of a flora characteristic of the distal intestine; resectio n with bypass of the ICJ results in the appearance of coliforms in the jejunal remnant. These changes in enteric flora do not correlate with content of specific SCFA and lactic acid in the small intestine.