Does glutamine reduce bacterial translocation? A study in two animal models with impaired gut barrier

Failure of intestinal barrier function and subsequent translocation of bact eria from the gut are believed to play a decisive role in the development o f systemic septic complications, for example, following major trauma or maj or abdominal surgery. This study evaluated: (a) the effect of glutamine on colonic microcirculation and electrophysiological parameters reflecting gut barrier function, (b) the translocation of live bacteria to extraintestina l organs, and (c) disease outcome in two animal models with impaired gut ba rrier function. Severe acute pancreatitis or colitis was induced in rats ra ndomized for therapy with or without glutamine (0.5 g/kg daily). After 48 h one animal group was prepared for intravital microscopy of colonic capilla ry blood flow and electrophysiological measurement of gut permeability; ano ther was killed after 96 h for histological and microbiological examination . In animals with pancreatitis, glutamine (Gln) supplementation significant ly improved gut permeability, i.e., Gin increased colonic transmucosal resi stance from 67+/-7 to 92+/-3 Omega/cm(2) and decreased mannitol flux throug h the epithelium by 53%. Capillary blood flow in the colonic mucosa was imp roved by 25%. The prevalence of pancreatic infections was reduced from 86% in animals on standard parenteral nutrition to 33% in animals given the Gin -enriched diet (P<0.05); mortality decreased by 32%. In colitis, Gin had no significant effect on these parameters except for improving colonic capill ary blood flow in colon segments not adjacent to the major injury site. Glu tamine supplementation improves colonic capillary blood flow, stabilizes gu t per meability, and reduces secondary pancreatic infections and mortality in severe rodent pancreatitis, but it is not helpful in colitis. This confi rms previous reports that glutamine stabilizes gut barrier function only in certain diseases. Our experimental data strongly suggest that acute pancre atitis (rather than colitis) is one of the diseases with gut barrier dysfun ction in which glutamine substitution may be helpful to reduce bacterial tr anslocation and should therefore be tested in a controlled clinical trial.