TREATMENT OF DIVERSION COLITIS BY SHORT-C HAIN FATTY-ACIDS - A BACTERIOLOGICAL STUDY

Objectives. - Bacterial imbalance may be involved in the pathogenesis of diversion colitis, via diminished production of short chain fatty a cids. The aim of the study was to evaluate the effectiveness of short chain fatty acids on microbial flora of patients with diversion coliti s and to compare this flora to the microbial flora of controls. Method s. - We prospectively evaluated the effectiveness of short chain fatty acids irrigation on bacterial flora of the excluded colon in 13 patie nts (8 males, 5 females; mean age : 43.7 years). The causes of diversi on were inflammatory bowel disease (n = 4) colonic cancer (n = 2) sigm oid diverticulitis with perforation (n = 3) ischio-rectal abcess (n = 2) and miscellaneous (n = 2). Patients were given, twice a day for 14 days in a double blind manner, a 60 mL enema containing either short c hain fatty acids (acetate : 60 mmol/L; propionate : 30 mmol/L; and n-b utyrate : 40 mmol/L) (group 1; n = 7) or isotonic NaCl (group 2; n = 6 ). Bacteriological studies were carried on before starting the trial ( D1) and 14 days later (D14). Results. - Before and after treatment, th ere was no difference between group 1 and group 2 concerning bacterial counts and species. Bacterial flora of patients with diversion coliti s was characterized by: a) an increase of the count of aerobic bacteri a; b) an increase of aerobic and aero-anaerobic species; c) the presen ce of black pigmented Cram negative anaerobic rods such as Prevotella intermedia and Porphyromonas asaccharolytica which were not found in r ectal flora of the control group (16 volunteers, mean age: 27 years). Conclusions. - These data suggest that: a) enema with short chain fatt y acids does not induce significant changes in the composition of the microbial flora in patients with diversion colitis; b) bacterial dysbi osis may be involved in pathogenesis of diversion colitis without invo lving the action of short chain fatty acids.