Probiotic therapy fails to improve cut permeability in a hapten model of colitis

Background: Studies in clinical and experimental inflammatory bowel disease (IBD) have shown disturbances in intestinal bacterial flora with an increa se in potentially pathogenic and a decrease in protective organisms. it was hypothesized that Lactobacillus plantarum species 299 (LP299), a probiotic , would ameliorate colitis and improve intestinal permeability in experimen tal colitis. This study investigated the effect of LP299 in the trinitroben zenesulfonic acid/ethanol (TNBS/E) rat model of colitis. Methods: Twelve we ek old mule Wistar rats were randomized to receive rectal instillates of ei ther TNBS/E (m = 48) or saline (n = 16). For the next 7 days the animals we re gavaged with 2.5 mi of oat fibre suspension containing 10(9) colony form ing units (CFU) of LP299 (LP299/OF), oat fibre suspension alone (OF) or no treatment. At the end of the experiment rats received radiolabelled polyeth ylene glycol and urine was collected for 24 h to assess permeability. Anima ls were then anaesthetized and colons were harvested for colon macroscopic scoring (CMS). Results: TNBS/E per rectum resulted in a greater CMS (P < 0. 001) and gut permeability (P = 0.006) than saline. Administration of LP299/ OF or oat fibre alone did not result in a reduction in CMS or gut permeabil ity when compared to colitic controls. Conclusions: LP299/OF, when administ ered after TNBS instillation, does not reduce the severity of colitis or im prove gut permeability in this hapten model of colitis.