Researchers studying the composition of the intestinal microflora in children diagnosed with irritable bowel syndrome (IBS) have found that specific types of bacteria are associated with the condition.
Disturbances in the normal balance of microbes that inhabit the gastrointestinal (GI) system have previouly been noted in adults suffering from IBS, the most frequently diagnosed GI illness in developed countries. The gut microflora usually benefits its human host by producing nutrients (e.g. vitamins B & K) and helping to regulate the immune system - factors such as antibiotic use, infection and poor diet can disturb the delicate balance of microbes and lead to disease, however.
Scientists based in Texas and The Netherlands undertook this latest study to determine if children suffering from IBS also carried an unusual mix of gut microbes compared to their healthy peers. The team report on their findings in the journal Gastroenterology.
A total of 44 children aged 7-12 years were involved in the study, 22 diagnosed with IBS according to paedeatric Rome III criteria and 22 healthy controls. The researchers used gene sequencing techniques and sophisticated computer analysis to detect thousands of different microbes in stool samples from the children in order to provide an accurate picture of their gut microbiomes - the complete ecosystem of microbes inhabiting their GI tracts.
Microbiomes associated with pediatric IBS were characterized by a significantly greater percentage of the bacterial class Gammaproteobacteria. A prominent member of this group in the children with IBS was Haemophilus parainfluenzae.
A hitherto unknown bacterium described as "Ruminococcus-like" was also found to be a significant member of the microbiomes of children diagnosed with IBS. The researchers suggesting that the analyses of stool samples they performed could be used to detect microbial signatures unique to other GI disorders and thus offer a means of diagnosis. This could be important for the diagnosis of IBS which is currently based on symptoms and exclusion of other conditions.
The scientists were also able to identify sub-types of IBS among the children through comparison of their microbiomes. For example, a greater frequency of pain was linked to an increased abundance of several bacteria from the genus Alistipes.
The findings go a long way to confirming that, as in adults with IBS, children suffering from the condition show signs of altered composition of their gut microflora. They also point to the possibility of using "microbial fingerprints" to diagnose IBS more accurately and perhaps even point the way to more effective treatments.
The study of the gut microbiome in IBS is still in its infancy but is certainly an area to watch in the future.
Source: Saulnier DM Riehle K Mistretta TA Diaz MA Mandal D Raza S Weidler EM Qin X Coarfa C Milosavljevic A Petrosino JF Highlander S Gibbs R Lynch SV Shulman RJ Versalovic J (2011) Gastrointestinal Microbiome Signatures Of Pediatric Patients With Irritable Bowel Syndrome Gastroenterology [Epub ahead of print] PMID:21741921