Introduction: Gonarthrosis, or osteoarthritis located in the knee, is a joint disease that causes the tissues of the affected joint to progressively degenerate. When there is a wear away of the synovial membrane due to this disease, its permeability increases, causing bacteria to thrive. The objective of this study is to identify whether Gonarthrosis is associated with a microbiota profile dominated by proinflammatory bacteria in the synovial space.

Methods: Synovial fluid samples were extracted from 57 patients diagnosed with stage 4 Gonarthrosis and were subsequently stored at -80 C. The extraction of total DNA was carried out with a specific kit for microbiome measurement. Gene libraries were created by PCR of the V3-V4 region of the 16S ribosomal gene to subsequently characterize the diversity of the microbiota using next-generation sequencing. The analysis of the results was conducted using the QIIME version 2 pipeline together with the GreenGenes database for taxonomic assignment and the R programming environment to determine the comparison of the relative abundance of taxa.

Results: The results determined that more than half of the samples contained bacteria of the genera Blautia_A_141781, Bacteroides_H, Lacticaseibacillus, and Akkermansia, among others. This information reveals that there are bacteria in the synovial space, contributing to the field of research on microbiota in spaces that are considered sterile, such as, in this case, joints affected by the degenerative disease Gonarthrosis.

Conclusion: In conclusion, it was detected that there are bacteria in the synovial space in people with Osteoarthritis. This work was financed by CONACyT 163235 INFR-2011-01 and SECTEI/249/2019—CM-SECTEI/109/2020—CM-SECTEI/124/2021, Convocatoria 2019.