Alteration in Gut Microbiome associated with Musculoskeletal Diseases and Arthritis

A study by the Inflammatory Arthritis Microbiome Consortium published in the Science Translational Medicine has shed new light on the intricate connection between musculoskeletal diseases and the gut microbiome. According to the research findings, which were based on the analysis of 440 stool shotgun metagenomes, up to 20% of adults worldwide are affected by musculoskeletal diseases, making it a significant global health concern.

While the link between the gut microbiome and inflammatory conditions has been suspected for some time, large-scale metagenomic evaluations had yet to trace the precise pathways through which gut immunity affects inflammatory arthritis. The Consortium's study sought to characterize the community structure and associated functional processes driving gut microbial involvement in arthritis.

The research included 221 adults diagnosed with rheumatoid arthritis, ankylosing spondylitis, or psoriatic arthritis, along with 219 healthy controls and individuals experiencing joint pain without underlying inflammation. The investigation revealed that the diagnosis of inflammatory arthritis explained approximately 2% of gut taxonomic variability, a figure comparable in magnitude to that seen in inflammatory bowel disease.

Among the key findings was the identification of several candidate microbes that exhibited differential carriage patterns in patients with elevated blood markers for inflammation. The results confirmed and expanded on previous observations of increased carriage of typically oral and inflammatory taxa, along with reduced abundance and prevalence of typical gut clades. These observations suggest that both distal inflammatory conditions and local conditions contribute to alterations in the gut microbial composition.

Moreover, the research team identified several differentially encoded pathways in the gut microbiome of patients with inflammatory arthritis. Notably, these included changes in vitamin B salvage and biosynthesis, as well as enrichment of iron sequestration. While some of these changes may have potential causal roles in inflammatory conditions, the researchers hypothesized that they primarily represent positive feedback responses to changes in the host's physiology and immune homeostasis.

Reference:

Thompson, K. N., Bonham, K. S., Ilott, N. E., Britton, G. J., Colmenero, P., Bullers, S. J., McIver, L. J., Ma, S., Nguyen, L. H., Filer, A., Brough, I., Pearson, C., Pawluk, A., Kiriakidis, S., … Taylor, P. C. (2023). Alterations in the gut microbiome implicate key taxa and metabolic pathways across inflammatory arthritis phenotypes. In Science Translational Medicine. American Association for the Advancement of Science (AAAS). https://doi.org/10.1126/scitranslmed.abn4722