Gut microbiota composition and functional changes in inflammatory bowel disease and irritable bowel syndrome, 2018, Vich Vila et al

[Andy]

Distinguishing two similar gut disorders
Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) are two of the most common diseases of the gastrointestinal tract. In new work, Vich Vila and colleagues have characterized the gut microbiota composition of both disorders using shotgun metagenomic sequencing of stool samples from 1792 individuals. Analyses involving bacterial taxonomy, metabolic functions, antibiotic resistance genes, virulence factors, and bacterial growth rates showed key differences between these two gut disorders. On the basis of gut microbiota composition differences, patients with IBD could be distinguished from those with IBS.

Abstract
Changes in the gut microbiota have been associated with two of the most common gastrointestinal diseases, inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS). Here, we performed a case-control analysis using shotgun metagenomic sequencing of stool samples from 1792 individuals with IBD and IBS compared with control individuals in the general population. Despite substantial overlap between the gut microbiome of patients with IBD and IBS compared with control individuals, we were able to use gut microbiota composition differences to distinguish patients with IBD from those with IBS. By combining species-level profiles and strain-level profiles with bacterial growth rates, metabolic functions, antibiotic resistance, and virulence factor analyses, we identified key bacterial species that may be involved in two common gastrointestinal diseases.

Paywalled at http://stm.sciencemag.org/content/10/472/eaap8914

The team set about sequencing the microbiomes from almost 1,800 people: 350 with IBD, 410 with IBS, and 1,000 healthy people as a comparison. But to do this, they needed to collect 1,800 microbiomes. That’s a lot of poop.

They found their participants through three different established banks of volunteers with well-established medical information for use in population studies. If you’ve ever peed in a cup at the doctor’s office, you can use your imagination to figure out how fecal samples are collected. But as an added challenge, fecal samples can’t be kept at room temperature, because that would allow certain bacteria to grow, interfering with the study results.

“So we asked all of them to collect the sample at home, put it in the freezer, and then we were driving around the Netherlands to pick up these samples,” says Vich Vila.

http://blogs.discovermagazine.com/c...iagnose-and-explain-ibs-and-ibd/#.XB4Uu_wuD5B