The bacteria that reside in the intestines of adults and
children with irritable bowel syndrome (IBS) differ from those
of healthy adults and children, according to 2 studies in the
November issue of Gastroenterology. Microorganisms account for
90% of the cells in our body (many cannot even be cultured);
only 10% of our cells are human. The large microbial mass in the
intestine is established at birth, and its composition is
determined by a combination of genetic and environmental
factors. The makeup of this microbiota has been proposed to
affect development of inflammatory bowel diseases and IBS. Only
recently have researchers developed technologies to quantify
these microbes. Mirjana Rajilić–Stojanović et al. performed
global and deep molecular analysis of fecal samples from 62
adult patients with IBS and 46 healthy adults. In a separate
study published in the same issue, Delphine M. Saulnier et al.
analyzed 71 stool samples from 22 children with IBS and 22
healthy children using 16S ribosomal RNA gene sequ