Gut-joint axis in knee synovitis: gut fungal dysbiosis and altered fungi–bacteria correlation network identified in a community-based study

Jiang, Ting; Liu, Ke; Li, Jiatian; Zhang, Yuqing; Zhang, Weiya; Doherty, Michael; Yang, Zidan; Yang, Tuo; Yang, Yuanheng; Weng, Qianlin; Luo, Xianghang; Xie, Hui; Li, Changjun; Ai, Kelong; Wei, Jie; Lei, Guanghua; Zeng, Chao

Abstract

Objectives: Knee synovitis is a highly prevalent and potentially curable condition for knee pain; however, its pathogenesis remains unclear. We sought to assess the associations of the gut fungal microbiota and the fungi–bacteria correlation network with knee synovitis. Methods: Participants were derived from a community-based cross-sectional study. We performed an ultrasound examination of both knees. A knee was defined as having synovitis if its synovium was ≥4 mm and/or Power Doppler (PD) signal was within the knee synovium area (PD synovitis). We collected faecal specimens from each participant and assessed gut fungal and bacterial microbiota using internal transcribed spacer 2 and shotgun metagenomic sequencing. We examined the relation of α-diversity, β-diversity, the relative abundance of taxa and the interkingdom correlations to knee synovitis. Results: Among 977 participants (mean age: 63.2 years; women: 58.8%), 191 (19.5%) had knee synovitis. β-diversity of the gut fungal microbiota, but not α-diversity, was significantly associated with prevalent knee synovitis. The fungal genus Schizophyllum was inversely correlated with the prevalence and activity (ie, control, synovitis without PD signal and PD synovitis) of knee synovitis. Compared with those without synovitis, the fungi–bacteria correlation network in patients with knee synovitis was smaller (nodes: 93 vs 153; edges: 107 vs 244), and the average number of neighbours was fewer (2.3 vs 3.2). Conclusion: Alterations of gut fungal microbiota and the fungi–bacteria correlation network are associated with knee synovitis. These novel findings may help understand the mechanisms of the gut-joint axis in knee synovitis and suggest potential targets for future treatment.

Citation

Jiang, T., Liu, K., Li, J., Zhang, Y., Zhang, W., Doherty, M., Yang, Z., Yang, T., Yang, Y., Weng, Q., Luo, X., Xie, H., Li, C., Ai, K., Wei, J., Lei, G., & Zeng, C. (2023). Gut-joint axis in knee synovitis: gut fungal dysbiosis and altered fungi–bacteria correlation network identified in a community-based study. RMD Open, 9(4), Article e003529. https://doi.org/10.1136/rmdopen-2023-003529

• Journal Article Type: Article
• Acceptance Date: Nov 24, 2023
• Online Publication Date: Dec 18, 2023
• Publication Date: Dec 18, 2023
• Deposit Date: Jan 3, 2024
• Publicly Available Date: Jan 10, 2024
• Journal: RMD open
• Electronic ISSN: 2056-5933
• Publisher: BMJ Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 4
• Article Number: e003529
• DOI: https://doi.org/10.1136/rmdopen-2023-003529
• Keywords: fungi, gastrointestinal microbiome, synovitis, ultrasonography, osteoarthritis, knee
• Public URL: https://nottingham-repository.worktribe.com/output/29259378
• Publisher URL: https://rmdopen.bmj.com/content/9/4/e003529
• Additional Information: © Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. http://creativecommons.org/licenses/by-nc/4.0/ This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.