title: Increase of faecal tryptic activity relates to changes in the intestinal microbiome: analysis of Crohn's disease with a multidisciplinary platform.
abstract: OBJECTIVE
  To investigate-by molecular, classical and functional methods-the microbiota in biopsies and faeces from patients with active Crohn's disease (CD) and controls.
  
  
  METHODS
  The microbiota in biopsies was investigated utilizing a novel molecular method and classical cultivation technology. Faecal samples were investigated by classical technology and four functional methods, reflecting alterations in short chain fatty acids pattern, conversion of cholesterol and bilirubin and inactivation of trypsin.
  
  
  RESULTS
  By molecular methods we found more than 92% similarity in the microbiota on the biopsies from the two groups. However, 4.6% of microbes found in controls were lacking in CD patients. Furthermore, NotI representation libraries demonstrate two different clusters representing CD patients and controls, respectively. Utilizing conventional technology, Bacteroides (alt. Parabacteroides) was less frequently detected in the biopsies from CD patients than from controls. A similar reduction in the number of Bacteroides was found in faecal samples. Bacteroides is the only group of bacteria known to be able to inactivate pancreatic trypsin. Faecal tryptic activity was high in CD patients, and inversely correlated to the levels of Bacteroides.
  
  
  CONCLUSIONS
  CD patients have compositional and functional alterations in their intestinal microbiota, in line with the global description hypothesis rather than the candidate microorganism theory. The most striking functional difference was high amount of faecal tryptic activity in CD patients, inversely correlated to the levels of Bacteroides in faeces.
authors.affiliation: Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Tore
authors.initials: T
authors.lastname: Midtvedt
authors.forename: Eugene
authors.initials: E
authors.lastname: Zabarovsky
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Norin
authors.forename: Johan
authors.initials: J
authors.lastname: Bark
authors.forename: Rinat
authors.initials: R
authors.lastname: Gizatullin
authors.forename: Vladimir
authors.initials: V
authors.lastname: Kashuba
authors.forename: Olle
authors.initials: O
authors.lastname: Ljungqvist
authors.forename: Veronika
authors.initials: V
authors.lastname: Zabarovska
authors.forename: Roland
authors.initials: R
authors.lastname: Möllby
authors.forename: Ingemar
authors.initials: I
authors.lastname: Ernberg
mesh_terms: D000328:Adult; D000368:Aged; D001439:Bacteroides / Q000302:isolation & purification; D016022:Case-Control Studies; D003424:Crohn Disease / Q000201:enzymology* / Q000382:microbiology; D004926:Escherichia coli / Q000302:isolation & purification; D005227:Fatty Acids / Q000737:chemistry; D005243:Feces / Q000737:chemistry / Q000201:enzymology* / Q000382:microbiology; D005260:Female; D006801:Humans; D008297:Male; D064307:Microbiota; D008875:Middle Aged; D014357:Trypsin / Q000737:chemistry*
chemical_list: D005227:Fatty Acids; D014357:Trypsin