Irritable bowel syndrome (IBS) is a significant gastrointestinal disorder with unknown etiology.
The symptoms can greatly weaken patients' quality of life and account for notable economical costs for society.
Contribution of the gastrointestinal microbiota in IBS has been suggested.
Dr Anna Kassinen and colleagues from Finland characterized putative differences in gastrointestinal microbiota between patients with IBS and control subjects.
These differences could potentially have a causal relationship with the syndrome.
|Some of the assays of phylotypes belonged to the genera Coprococcus|
Microbial genomes from fecal samples of 24 patients with IBS and 23 controls were collected, pooled in a groupwise manner.
The team fractionated the genomes according to their guanine cytosine content.
Selected fractions were analyzed by extensive high-throughput 16S ribosomal RNA gene cloning and sequencing of 3753 clones.
Some of the revealed phylogenetic differences were further confirmed by quantitative polymerase chain reaction assays on individual samples.
The research team found that the coverage of the clone libraries of IBS subtypes and control subjects differed significantly.
The samples were also distinguishable by the Bayesian analysis of bacterial population structure.
The team noted significant differences between the clone libraries in several bacterial genera.
These differences could be verified by quantitative polymerase chain reaction assays of phylotypes belonging to the genera Coprococcus, Collinsella, and Coprobacillus.
Dr Kassinen's team concludes, "The study showed that fecal microbiota is significantly altered in IBS."
"Further studies on molecular mechanisms underlying these alterations are needed to elucidate the exact role of intestinal bacteria in IBS."