The Human Mesenteric Lymph Node Microbiome Differentiates Between Crohn's Disease and Ulcerative Colitis

Study information

Reviewed Marked as Reviewed by Rimsha Azhar on 2021/02/09

study design

cross-sectional observational, not case-control

Citation

PMID PubMed identifier for scientific articles.

30239655

DOI Digital object identifier for electronic documents.

10.1093/ecco-jcc/jjy136

URI

Authors

Kiernan MG, Coffey JC, McDermott K, Cotter PD, Cabrera-Rubio R, Kiely PA, Dunne CP

Journal

Journal of Crohn's & colitis

Year

2019

Background and Aims: Mesenteric lymph nodes are sites in which translocated bacteria incite and progress immunological responses. For this reason, understanding the microbiome of mesenteric lymph nodes in inflammatory bowel disease is important. The bacterial profile of Crohn's disease mesenteric lymph nodes has been analysed using culture-independent methods in only one previous study. This study aimed to investigate the mesenteric lymph node microbiota from both Crohn's disease and ulcerative colitis patients. Methods: Mesenteric lymph nodes were collected from Crohn's disease and ulcerative colitis patients undergoing resection. Total DNA was extracted from mesenteric lymph nodes and assessed for the presence of bacterial DNA [16S]. All work was completed in a sterile environment using aseptic techniques. Samples positive for 16S DNA underwent next-generation sequencing, and the identity of bacterial phyla and species were determined. Results: Crohn's disease mesenteric lymph nodes had a distinctly different microbial profile to that observed in ulcerative colitis. The relative abundance of Firmicutes was greater in nodes from ulcerative colitis patients, whereas Proteobacteria were more abundant in Crohn's disease. Although species diversity was reduced in the mesenteric lymph nodes of patients with Crohn's disease, these lymph nodes contained greater numbers of less dominant phyla, mainly Fusobacteria. Conclusion: This study confirms that there are distinct differences between the Crohn's disease and ulcerative colitis mesenteric lymph node microbiomes. Such microbial differences could aid in the diagnosis of Crohn's disease or ulcerative colitis, particularly in cases of indeterminate colitis at time of resection, or help explain their mechanisms of development and progression.

Experiment 1

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Reviewed Marked as Reviewed by Rimsha Azhar on 2021/02/09

Curated date: 2021/01/10

Curator: WikiWorks

Revision editor(s): WikiWorks, Victoria

Subjects

Location of subjects: Ireland

Host species Species from which microbiome was sampled. Contact us to have more species added.: Homo sapiens

Body site Anatomical site where microbial samples were extracted from according to the Uber Anatomy Ontology: Mesenteric lymph node

Condition The experimental condition / phenotype studied according to the Experimental Factor Ontology: Inflammation of the large intestine

Group 0 name Corresponds to the control (unexposed) group for case-control studies: Ulcerative colitis

Group 1 name Corresponds to the case (exposed) group for case-control studies: Crohn's disease

Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group: histopathologivally diagnosed ulcerative colitis and crohn's disease

Group 0 sample size Number of subjects in the control (unexposed) group: 8

Group 1 sample size Number of subjects in the case (exposed) group: 5

Lab analysis

Sequencing type: 16S

16S variable region One or more hypervariable region(s) of the bacterial 16S gene: V3-V4

Sequencing platform Manufacturer and experimental platform used for quantifying microbial abundance: Illumina

Statistical Analysis

Data transformation Data transformation applied to microbial abundance measurements prior to differential abundance testing (if any).: relative abundances