A Pyrosequencing Study in Twins Shows That Gastrointestinal Microbial Profiles Vary With Inflammatory Bowel Disease Phenotypes

[Igor_Passau]

The composition of the gastrointestinal microbiota is thought to have an important role in the etiology of inflammatory bowel diseases (IBDs) such as Crohn's disease (CD) and ulcerative colitis (UC). Interindividual variation and an inability to detect less abundant bacteria have made it difficult to correlate specific bacteria with disease. We used 454 pyrotag sequencing to determine the compositions of microbial communities in feces samples collected from a cohort of 40 twin pairs who were concordant or discordant for CD or UC, and in mucosal samples from a subset of the cohort. The cohort primarily comprised patients who were in remission, but also some with active disease. The profiles of the microbial community differed with disease phenotypes; relative amounts of bacterial populations correlated with IBD phenotypes. The microbial compositions of individuals with CD differed from those of healthy individuals, but were similar between healthy individuals and individuals with UC. Profiles from individuals with CD that predominantly involved the ileum differed from those with CD that predominantly involved the colon; several bacterial populations increased or decreased with disease type. Changes specific to patients with ileal CD included the disappearance of core bacteria, such as Faecalibacterium and Roseburia, and increased amounts of Enterobacteriaceae and Ruminococcus gnavus. Bacterial populations differ in abundance among individuals with different phenotypes of CD. Specific species of bacteria are associated with ileal CD; further studie
http://www.citeulike.org/user/dzunkova/article/7787895

 

[juljul]

Hi Igor,
There are implications for faecal transplants or faecal constructs.

Emma-Alen Vercoe, at the University of Guelph (Ontario, Canada) has developed an artificial stool she has called RePOOPulate, which looks to be effective to cure chronic Clostridium difficile infections.

"She made the super-probiotic from purified intestinal bacterial cultures grown in "Robo-gut" equipment in a Guelph laboratory that mimics the environment of the large intestine." [verbatim].
"Allen-Vercoe hopes doctors will one day use the RePOOPulate concept to treat other GI conditions, such as inflammatory bowel disease, obesity and even autism by replacing abnormal gut microbial ecosystems." [verbatim].
"The method may be modified to suit individual patient needs, is easily reproduced, and is more appealing to many patients and physicians, she said." [verbatim].
[ref: "Synthetic Stool Can Cure C. Difficile Infection, Study Suggests", Jan 8, 2013, Science Daily, :::link for this ref::: ]

My comments in the light of the Swedish study (the abstract you have kindly posted) ...though I cannot get access to the whole paper so my comments are based on the abstract alone).......
As Emma had said, faecal constructs look like they need to be tailor made to suit patient needs.....dependent on whether the IBD is predominantly in the small intestine or large intestine...or both....perhaps with emphasis on core bacteria if the patient has ileal Crohn's Disease (CD) (Swedish study).
According to this Swedish study, faecal dysbiosis does not look to be a major factor in the etiology of Ulcerative Colitis (UC). However, other studies suggest otherwise [for example some research papers born out of research from the University of Dundee 2003, 2004....).. Different techniques have been employed. There are far-reaching implications for techniques. An up-to-date paper (2012) based on research from a US study, concludes that dysbiosis is a factor in the pathogenesis of UC. (link for the full paper).

The Swedish study versus other studies might suggest the limitations of 454 pyrotag sequencing over other techniques such as fluorescent light miscroscopy with 16S rRNA oligonucleotide probes (Scottish studies 2003 and 2004, links above) and PCR-based methods (US study 2012, link above).

There will be other papers. I did not really have time to do a thorough literature search.

I think it is now well-known among the scientific community that bacterial dysbiosis places a role in the etiology of the different forms of IBD. I think the medical community are taking some time to catch on ....most NHS hospitals in the UK, not linked to university medical schools at least, employ very limited techniques when looking to detect bacterial populations in individiual patients (such as dry agar plate cultures)...probably down to cost and budgets....the usual scenario then Some of the highly sensitive and specific techniques could be expensive. It nearly always comes down to money!!!

Thanks for the post Igor.

~ juljul


Full refs:

S Macfarlane, E Furrie, J.H. Cummings, & G.T. Macfarla, "Chemotaxonomic analysis of bacterial populations colonizing the rectal mucosa in patients with ulcerative colitis." Clin Infect Dis. 2004 Jun 15;38(12):1690-9.
J. H. Cummings*, G. T. Macfarlane, & S. Macfarlane", "Intestinal Bacteria and Ulcerative Colitis", Curr. Issues Intest. Microbiol. (2003) 4: 9-20.
M Sasaki & J-M A. Klapproth, "The Role of Bacteria in the Pathogenesis of Ulcerative Colitis", Journal of Signal Transduction Volume 2012 (2012), Article ID 704953, 6 pages