Alterations in the gastrointestinal tract microbiome may play an important role in many digestive conditions.  A recent article examines microbiome alterations in children with severe ulcerative colitis (UC) (Inflamm Bowel Dis 2012; 18: 1799-1808).

Stool samples from 26 healthy children and 27 children with severe UC were prospectively studied.  After DNA extraction, PCR amplification and microarray hybirdization were performed and analyzed.   None of the patients in the study had received antibiotics or probiotics in the preceding month.

Key findings:

• There were substantial reductions in “richness,” diversity, and evenness of the gut microbiome in UC patients.  (Richness is a term used to reflect the number of detected phylospecies.)
• There was a decrease in signal in almost all  phylospecies.
• The number of phylospecies was reduced in UC (266 ± 69) vs controls (758 ± 3)
• Steroid responders had even fewer phylospecies compared with responders (142 ± 49  vs. 338 ± 62)

It is not surprising that the stools from these children are much different.  The issues of causation and whether a snapshot of the microbiome diversity will have clinical relevance is not clear.  It is possible that antimicrobials may make an individual more susceptible to inflammatory bowel disease by altering the individual’s microbiome.

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