Impaired bacterial flora in human excluded colon.

Abstract

SUMMARY We compared the rectal microflora of 16 patients with surgically excluded colorectum with 16 healthy controls. The cause of diversion was inflammatory bowel disease (n=10), colon cancer (n=3), miscellaneous (n=3). Six patients had a diversion colitis. In the excluded colorectum, the total bacterial count was only slightly lower than controls but the variety of the flora was significantly reduced. This reduction was confined to strict anaerobes, mainly the genus Eubacterium and Bifidobacterium. Among aerobes, enterobacteria were more often isolated than in controls. This altered microflora of excluded colorectum could be involved in the mucosal damage observed in some cases.Human colon contains an unique microbial ecosystem composed by a large variety of bacteria mainly strict anaerobes.' The substrates for the microbial development are both exogenous (food residues not digested by human enzymes) and endogenous (such as bile and mucus).'2Beneficial effects of the microflora on host are resistant to colonisation3 and the formation of short chain fatty acids, substrates for the colonocytes.4In patients undergoing colostomy the remaining colon and rectal segment are completely isolated from the upper gastrointestinal tract. Diversion of the faecal stream may be associated with diversion colitis.5 Although, the pathophysiology of this disorder is unknown, the bacterial flora might be implicated either by implantation of harmful strains or by partial loss of the normal colonic microflora.6 Only scarce information exists, however, about the bacterial population of excluded colons.7 The aim of the present study was to determine the microflora of excluded colon in 16 patients operated on for various colonic disease. Methods PATIENTSThe clinical data of the 16 patients are summarised in

Identification and Functional Characterization of Arylamine N -Acetyltransferases in Eubacteria: Evidence for Highly Selective Acetylation of 5-Aminosalicylic Acid

“…We detected NAT activity with 5-ASA in species of Proteobacteria and Bacteroides from the intestinal microflora, including members known to be overrepresented in inflammatory bowel diseases. These microbes include the aerobes E. coli, P. aeruginosa, and Klebsiella (31) and the obligate anaerobes Bacteroides (3,46) and C. difficile (52). Of the various arylamines tested here, 5-ASA was the most efficiently acetylated by bacterial NATs (Tables 2, 3, 4, and 5).…”

Good fences make good neighbors

“…39 Deprivation of the fecal stream and resultant alterations of luminal microbial populations may, in part, explain the colitis that develops in excluded segments of distal colon when a proximal ostomy is created. 40 This diversion colitis generally abates when fecal flow is restored.…”

Evaluation of topical n-acetylcysteine in diversion colitis

“…This disease was discovered in the 1970's, but it was not well understood until1981, when Glotzer et al 5 described ten cases of a form of colitis that developed in colonic segments without fecal stream, in patients that did not present prior evidence of IBDs 4,5 . Subsequent studies attributed inflammation to reduced supply of SCFAs to mucosa cells of the segment without fecal stream [6][7][8][9][10] . The application of SCFAs in the excluded colon was experimentally demonstrated to improve the inflammatory process, while the interrupted application promoted the disease dissemination 10 .…”