Two of the most important and largest microbiome studies ever undertaken in patients with chronic inflammatory bowel disease have been conducted by a team of researchers in Cork from APC Microbiome Ireland SFI Research Centre. The research, which also includes collaborating scientists from the UK, USA and elsewhere took two different approaches to show that patients with both Crohn’s disease and ulcerative colitis have disturbances in their microbiome (the collection of bacteria living in the human gut).

The first study which has appeared in the prestigious journal Nature Communications, showed important changes in the microbes sampled at colonoscopy which were directly associated with inflammation in the colon.

The second study followed 700 Irish and Canadian patients over time and revealed disturbances in the microbiome associated with relapses of disease. The work published in the journal Gut, will open the way for doctors to be able to predict relapses of disease before patients develop symptoms.

“We are delighted that both of our research approaches showed complementary, albeit important, results which will be of benefit to patients in the future” said Dr Marcus Claesson, leader of this research at APC Microbiome Ireland SFI Research Centre.

“The work is an important example of what can be achieved when clinicians and basic scientists collaborate” said Prof Fergus Shanahan, one of the researchers on the project.

Inflammatory bowel disease is comprised of two chronic inflammatory conditions, ulcerative colitis and Crohn’s disease, which affects tens of thousands of patients in Ireland. While the condition can be controlled with drugs, the unpredictability of relapses is a major challenge for patients and is one of the reasons why the microbiome is so important in providing markers to predict relapse.

“While ethnicity, diet and geographical location were found to contribute to microbiota variation globally, it is the variation in microbiota composition within individuals followed over time which increases the power of microbiome markers to predict relapse. This has implications for future microbiota studies and for the development of precision medicine” added Dr Claesson.

Original References:
Colonic microbiota is associated with inflammation and host epigenomic alterations in inflammatory bowel disease Fergal Ryan et al Nature Communications volume 11, Article number: 1512 (2020) 
Ranking microbiome variance in inflammatory bowel disease: a large longitudinal intercontinental study  Adam G Clooney*, Julia Eckenberger* et al Gut (2020)