Cross-sectional associations of radiographic multiple joint osteoarthritis and symptoms, laboratory values and the gut microbiota: A multimodal study in humans and pet dogs

Objective

To describe the frequency of multiple joint osteoarthritis (MJOA) and symptoms, and associations with fecal microbial diversity and composition, in cohorts of humans and dogs.

Design

Human participants enrolled in the community-based Johnston County Health Study (JoCoHS), and an independent cohort of pet dogs, were included. Questionnaires, functional assessments, standardized multiple joint radiographs, and pain assessments, blood and fecal samples were obtained. Microbiome analysis was done by 16S rRNA amplicon sequencing. MJOA was defined as ≥3 unique joint sites involved; symptom burden was based on self-reported/proxy measures of pain. Descriptive statistics and Spearman correlations with Benjamini-Hochberg correction were used to determine relationships among lab tests, pain, and microbiome diversity measures.

Results

Human participants (n ​= ​100, 63 ​% women, mean age 56 years, mean body mass index 34 ​kg/m²) and 115 pet dogs (40 ​% spayed females, 57 ​% neutered males, mean age 8 years, mean weight 27 ​kg) were included; 20 ​% had radiographic MJOA (rMJOA). Microbial α-diversity did not differ between participants with or without rMJOA. However, lower levels of the Christensenellaceae R-7 group and Lachnoclostridium in humans, and the butyrate-producing bacterium, Faecalibacterium in dogs, were moderately correlated with greater pain severity, as were higher levels of Escherichia-Shigella in dogs. Faecalibacterium was more abundant in humans without rMJOA.

Conclusions

These two cohorts demonstrated remarkably similar frequencies of rMJOA (∼20 ​%), supporting the use of dogs to model naturally occurring MJOA. Taxa potentially related to rMJOA and pain were identified in this preliminary analysis, providing new insights into links between dysbiosis and MJOA.