CD and UC Patients Distinguished by Mesenteric Lymph Node Microbiome

Since Crohn’s Disease (CD) and Ulcerative Colitis (UC) have been proposed to result from an overreactive immune response to the gut microbiome in genetically susceptible individuals, there has been considerable interest in characterizing certain aspects of the gut microbiome as they relate to inflammatory bowel disease, not only to potentially improve the understanding of mechanisms regulating disease pathogenesis, but also perhaps to one day develop superior medical interventions. According to research published in the Journal of Crohn’s and Colitis, UC and CD patients can be differentiated based on their mesenteric lymph node microbiome.

What are Mesenteric Lymph Nodes (MLNs) and why do they matter to UC and CD patients?

MLNs are sites of immune cell trafficking and congregation within and near the intestines, representing important outlets for interaction between the gut microbiome and the immune system.

In this study, Dr. Miranda Kiernan, Dr. Colum Dunne, and a team of other scientists from the University of Limerick in Ireland analyzed the distribution of bacterial phyla and species within the Mesenteric Lymph Nodes (MLNs) of UC and CD patients, demonstrating that these patient populations indeed carry distinctly different bacterial microbiomes.

While other studies have assessed the bacterial microbiome of fecal matter and the intestinal mucosa, this was the first project to explore whether the microbiome of MLNs differs between UC and CD patients.

The MLNs of UC patients were enriched for Proteobacteria and those of CD patients for less common phyla such as Fusobacteria. The distribution of bacterial species was less diverse in CD patients, containing comparatively fewer types of bacteria.

These findings regarding the mesenteric lymph node microbiome could be used to confirm the diagnosis of patients with indeterminate colitis and may shed light on mechanisms contributing to the development and progression of these inflammatory bowel diseases.

Kiernan MG, Coffey JC, McDermott K, et al. (2019) The Human Mesenteric Lymph Node Microbiome Differentiates Between Crohn’s Disease and Ulcerative Colitis. J Crohns Colitis, 13(1): 58-66.

Read more about the latest research and therapies related to autoimmune diseases.