Is IBD going viral? Pursuant to last month’s journal club discussion on the importance of examining the fungal mycobiome, a closer look at the intestinal virome seemed like the logical next step. Eukaryotic viruses have the ability to interact with IBD risk genes to potentially alter disease (Basic et al, 2014, Cadwell et al, 2010). Various environmental stimuli (nitric oxide, antibiotics) can modulate the relationship between virus and host, including bacteriophages and their hosts. Changes such as these may be inciting factors of disease onset or flare-ups, thus it is important to better understand the role of viruses in gut physiology.
This study published in Cell in January of 2015 examined the composition of viruses in multiple inflammatory bowel disease patient cohorts and also compared IBD patients to their household controls. The authors found a significant expansion of one group of bacteriophages that was reportedly not secondary to IBD-associated decreases in bacterial diversity. Increased richness of caudovirales was associated with both CD and UC. This was often accompanied by a decrease in the other predominant bacteriophage species, microviridae. Other viruses comprised less than 5% of all viral sequences that were detected.
We’ll meet again at West End pub at 3:30 pm. The primary objectives of this week’s discussion will be to discuss current and potential methods for reliably sequencing viral DNA, as well as the importance of doing so.
A few papers for relevant background information:
Bernstein et al, 2000. Viruses and inflammatory bowel disease: is there evidence for a causal association? http://www.ncbi.nlm.nih.gov/pubmed/10701147
Breitbart et al, 2003. Metagenomic analyses of an uncultured viral community from human feces. http://www.ncbi.nlm.nih.gov/pubmed/14526037
Perez-Brocal et al. Study of the viral and microbial communities associated with Crohn’s disease: a metagenomic approach. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3696940/
Wagner et al, 2013. Bacteriophages in gut samples from pediatric Crohn’s disease patients: metagenomic analysis using 454 pyrosequencing. http://www.ncbi.nlm.nih.gov/pubmed/23749273
Wang et al, 2015. Metagenomic analysis of microbiome in colon tissue from subjects with inflammatory bowel diseases reveals interplay of viruses and bacteria. http://www.ncbi.nlm.nih.gov/pubmed/25939040