title: Does the intestinal bifidobacterial colonisation affect bacterial translocation?
abstract: The aim of this work was to investigate the possible role of the intestinal anaerobic flora (especially bifidobacteria) in regulating bacterial translocation (BT) which can be defined as the passage of intestinal microbes through the mucosa to internal organs. Default in BT regulation concurs with pathogenesis of sepsis in various human conditions, such as acute pancreatitis, cirrhosis, necrotising enterocolitis or multiple organ failure. The intestinal flora was studied in human flora associated mice (HF mice) and BT was quantified in Peyer's patches (PP), blood, spleen, liver and lungs. HF mice displayed a heterogenic intestinal colonisation with bifidobacteria. High colonisation of both caecum and colon by bifidobacteria led to a poorer bacterial contamination of blood, liver and lungs. Moreover, ileal, caecal and colonic bifidobacterial counts negatively correlated with the bacterial dissemination (number of contaminated organs per mouse). In contrast, Bacteroides fragilis group counts positively correlated with bacteraemia, lungs contamination or bacterial dissemination. Additionally, clostridia localised in the colon affected bacterial uptake by PP and lungs contamination as indicated by positive correlations between bacterial populations in these respective locations. These results indicate that bifidobacteria, when established in high counts, reduced BT to liver, blood and lungs, whereas B. fragilis group favoured the bacterial passage. Clostridia established in the distal ileum also seemed to favour BT to lungs. The manipulation of the bacterial flora to optimise the regulatory effect on BT should therefore focus on the selective promotion of bifidobacteria and avoid an increase in potentially detrimental populations such as B. fragilis group and clostridia.
authors.affiliation: Laboratoire de Microbiologie, Faculté des Sciences Pharmaceutiques et Biologiques, 3 rue du Pr. Laguesse, B.P. 83, 59006 Lille Cedex, France. marie-benedicte.romond@univ-lille2.fr
authors.forename: Marie-Bénédicte
authors.initials: MB
authors.lastname: Romond
authors.forename: Michel
authors.initials: M
authors.lastname: Colavizza
authors.forename: Catherine
authors.initials: C
authors.lastname: Mullié
authors.forename: Nicolas
authors.initials: N
authors.lastname: Kalach
authors.forename: Odile
authors.initials: O
authors.lastname: Kremp
authors.forename: Christine
authors.initials: C
authors.lastname: Mielcarek
authors.forename: Daniel
authors.initials: D
authors.lastname: Izard
mesh_terms: D000818:Animals; D018988:Bacterial Translocation; D001441:Bacteroides fragilis / Q000502:physiology; D001644:Bifidobacterium / Q000502:physiology*; D003013:Clostridium / Q000502:physiology; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H