Microbial network alterations identified in Crohn’s disease

A new study identifies specific alterations of the gut microbial network in Crohn’s disease!

The microbiome has long been thought to be implicated in Crohn’s disease (CD) and ulcerative colitis (UC), the two forms of IBD. After all, IBD patients tend to have altered reactivity to microbes, and animal models have shown that gut microbes are necessary for the development of IBD.

Now, researchers from Bern, Switzerland have mined the data from two independent cohorts of IBD patients to determine which bacterial populations, and which bacterial relationships, get thrown out of whack in IBD. They examined mucosal biopsy microbiotas from 270 patients with Crohn’s disease, 232 patients with ulcerative colitis, and 227 healthy individuals across these two cohorts.

They found that CD, in particular, was characterized by lower bacterial diversity and a loss of beneficial bacterial taxa, including Faecalibacterium, Blautia, and Bifidobacterium, which all contribute to the production of short-chain fatty acids in the gut. CD patients with higher levels of these keystone taxa tended to have a healthier lifestyle that included more exercise, a more quiescent disease course, and a greater likelihood of responding to anti-TNFalpha drug therapies.

The researchers next looked at which bacteria were most associated with increases in disease activity. Only Enterobacteriaceae and Klebsiella in CD and Ruminococcus and Prevotella in UC showed consistent alignment with increased disease activity.

Complex co-occurrence network analysis identified Faecalibacterium and Ruminococcus as some of the most influential taxa in the microbiota of CD patients across both cohorts. Future research will hopefully be able to use these microbial “maps” to identify personalized treatment options that target these keystone taxa!

Read the full study here: www.nature.com/articles/s41591-018-0308-z

Microbial network alterations identified in Crohn’s disease

A new study identifies specific alterations of the gut microbial network in Crohn’s disease!

The microbiome has long been thought to be implicated in Crohn’s disease (CD) and ulcerative colitis (UC), the two forms of IBD. After all, IBD patients tend to have altered reactivity to microbes, and animal models have shown that gut microbes are necessary for the development of IBD.

Now, researchers from Bern, Switzerland have mined the data from two independent cohorts of IBD patients to determine which bacterial populations, and which bacterial relationships, get thrown out of whack in IBD. They examined mucosal biopsy microbiotas from 270 patients with Crohn’s disease, 232 patients with ulcerative colitis, and 227 healthy individuals across these two cohorts.

They found that CD, in particular, was characterized by lower bacterial diversity and a loss of beneficial bacterial taxa, including Faecalibacterium, Blautia, and Bifidobacterium, which all contribute to the production of short-chain fatty acids in the gut. CD patients with higher levels of these keystone taxa tended to have a healthier lifestyle that included more exercise, a more quiescent disease course, and a greater likelihood of responding to anti-TNFalpha drug therapies.

The researchers next looked at which bacteria were most associated with increases in disease activity. Only Enterobacteriaceae and Klebsiella in CD and Ruminococcus and Prevotella in UC showed consistent alignment with increased disease activity.

Complex co-occurrence network analysis identified Faecalibacterium and Ruminococcus as some of the most influential taxa in the microbiota of CD patients across both cohorts. Future research will hopefully be able to use these microbial “maps” to identify personalized treatment options that target these keystone taxa!

Read the full study here: www.nature.com/articles/s41591-018-0308-z