Bacterium 'to blame for Crohn's'

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Bacterium 'to blame for Crohn's'

http://news.bbc.co.uk/2/hi/health/7679347.stm

BBC NEWS

2008/10/21

 

 

Researchers believe the lack of a specific bacterium in the gut may

be a cause of Crohn's disease.

 

A shortage of naturally-occurring bacteria is thought to trigger the

inflammatory gastrointestinal disorder by over-stimulating the immune

system.

 

Now a French team has highlighted the bug, Faecalibacterium

prausnitzii, which they show secretes biochemicals that reduce

inflammation.

 

The study appears in Proceedings of the National Academy of Sciences.

 

CROHN'S DISEASE

Can affect any part of the gut

 

Most commonly affects the lower end of the small intestine - the

ileum

 

Symptoms include, pain, ulcers and diarrhoea

 

Medication can relieve symptoms, but surgery to remove part of the

gut may be required

 

The researchers, from the Institut National de la Recherche

Agronomique, had already shown that patients with Crohn's disease

have a marked deficiency in bacteria from the Clostridium leptum

group.

 

Their latest work shows that F. prausnitzii - a major component of

this group - accounts for a large part of the deficit.

 

Bowel surgery

 

The researchers found that Crohn's patients who underwent bowel

surgery were more likely to experience a recurrence of the condition

if they had low levels of F. prausnitzii.

 

And in experiments on cultured cells, they showed that liquid in

which F. prausnitzii had been grown provided an anti-inflammatory

effect.

 

The researchers said that if ongoing animal trials prove successful,

human patients could benefit from a probiotic treatment with F.

prausnitzii.

 

Dr Anton Emmanuel, medical director of the digestive disorders

charity Core, called the study " exciting " and agreed it raised the

possibility of a therapeutic " replacement " therapy.

 

" It would be interesting to see how this finding relates to the

emerging body of evidence looking at genetic changes in some patients

with Crohn's disease, with the known abnormal gene being one that

codes for the body's ability to recognise foreign bacteria. "

 

Dr John Bennett, chairman of Core, said there was growing evidence

that micro-organisms combined with immunological weaknesses to either

cause, or exacerbate Crohn's symptoms.

 

However, he said: " The gut contains a huge number and variety of

organisms, and many of them have been investigated without any single

one seeming to be entirely responsible. "

 

Dr Bennett said scientists were testing the theory that harmful

bacteria could be neutralised, or at least counter-acted, by

preparations of beneficial " probiotic " micro-organisms, but as yet no

definitive proof of their effect had been produced.