Consequences of biofilm and sessile growth in the large intestine

Medical Research Council, Dunn Clinical Nutrition Centre, Cambridge, UK.

The human colonic ecosystem is an extremely complex environment comprised of several hundred different strains of bacteria. Studies were undertaken to determine whether these organisms formed metabolic or genotypically distinct assemblages in the gut microbiota in relation to polysaccharide fermentation. Measurements of depolymerizing enzymes (4 polysac-charidases, 6 glycosidases) showed that specific amylase and pectinase activities were comparable in bacteria desorbed from the surfaces of food particles and in non-particulate organisms. However, xylanase, beta-xylosidase, arabinogalac-tanase, alpha-arabinofuranosidase, and beta-galacturonidase activities were always significantly greater in particulate bacteria. Short-term in vitro fermentations with both groups of bacteria showed marked differences in relative rates of starch, arabinogalactan, and mucin metabolism, while rates of fermentation product formation with pectin and xylan were broadly comparable. Significant differences were observed with respect to formation of individual fermentation products, especially when mucin or pectin were substrates, where particulate bacteria produced proportionally higher amounts of acetate. Bacteriological studies showed that communities of polymer-degrading bacteria and other groups of intestinal anaerobes growing on particulate matter were essentially similar to those occurring elsewhere in the gut lumen, at genus and species levels. In vitro colonization experiments demonstrated that a variety of polysaccharide-fermenting bifidobacteria and bacteroides--together with other cross-feeding organisms such as peptostreptococci, fusobacteria, and coliforms--rapidly attached to particulate intestinal materials.

This article has been cited by other articles:

				S. Macfarlane, E. J. Woodmansey, and G. T. Macfarlane Colonization of Mucin by Human Intestinal Bacteria and Establishment of Biofilm Communities in a Two-Stage Continuous Culture System Appl. Envir. Microbiol., November 1, 2005; 71(11): 7483 - 7492. [Abstract] [Full Text] [PDF]

				A. J. Wolfe The Acetate Switch Microbiol. Mol. Biol. Rev., March 1, 2005; 69(1): 12 - 50. [Abstract] [Full Text] [PDF]

				S J Langlands, M J Hopkins, N Coleman, and J H Cummings Prebiotic carbohydrates modify the mucosa associated microflora of the human large bowel Gut, November 1, 2004; 53(11): 1610 - 1616. [Abstract] [Full Text] [PDF]

				J. E. Kerschner, T. K. Meyer, and A. Burrows Chinchilla Middle Ear Epithelial Mucin Gene Expression in Response to Inflammatory Cytokines Arch Otolaryngol Head Neck Surg, October 1, 2004; 130(10): 1163 - 1167. [Abstract] [Full Text] [PDF]