Introduction: Recent research indicated a strong link between the gut microbiota and osteoarthritis. However, the complex interplay between the gut microbiota, serum metabolites, and the progression of osteoarthritis in affected individuals remains largely unexplored. This study aimed to investigate the characteristics of the gut microbiota and serum metabolites in patients with osteoarthritis.Methods: Participants with either healthy knees or osteoarthritis were enrolled and categorized into healthy control (HC) and osteoarthritis (OA) groups. Fecal and blood samples were collected for 16S rRNA gene sequencing, metabolomic analysis via liquid chromatography–mass spectrometry (LC-MS), and integrated evaluation.Results: The results showed no significant variation in gut microbiota richness and diversity between the two groups. However, the abundance of Bacteroides plebeius and Faecalibacterium prausnitzii was reduced in the OA group, both of which are known for their potential as next-generation probiotics for human health. Metabolomic analysis indicated that serum metabolites, including pyrogallol and 3-hydroxybutyrate (3HB), were significantly lower in the OA group. These metabolites are known to positively impact osteoarthritis progression and other diseases and demonstrated good diagnostic performance for distinguishing osteoarthritis patients from healthy controls. Correlation analysis revealed a positive correlation between Bacteroides plebeius and Faecalibacterium prausnitzii and between pyrogallol and 3HB.Discussion: This study highlighted specific gut microbiota and serum metabolite profiles in osteoarthritis patients, suggesting that the specific changes in bacteria and derived metabolites are closely tied to osteoarthritis progression. This underscores the potential of gut microbiota and serum metabolites as modifiable elements and therapeutic targets for osteoarthritis prevention.

Background: Hemorheological parameters have been confirmed to be related with deep vein thrombosis (DVT). This study is aimed to verify whether preoperative erythrocyte electrophoresis exponent was associated with postoperative deep vein thrombosis (DVT) risk after total knee arthroplasty (TKA) in patients with primary knee osteoarthritis (KOA). Methods: From March 2010 to May 2020, a total of 750 consecutive KOA patients who accepted unilateral TKA were enrolled. They were divided into DVT (176 patients) and non-DVT groups (574 patients) according to the examination results of the Doppler ultrasound of deep veins in both lower limbs on postoperative day 3. The Chi-square test, Student’s t test, and multivariate logistic regression analysis were performed to analyze the correlation of erythrocyte electrophoresis exponent and DVT risk in 2 groups. Receiver operating characteristic (ROC) analysis was used to assess predictive value of erythrocyte electrophoresis exponent for DVT. Results: A low erythrocyte electrophoresis exponent was a significant risk factor for DVT in patients with primary KOA (p < 0.05), especially in females when stratified by gender (p < 0.05). Conclusions: The findings suggest that lower erythrocyte electrophoresis before surgery may be independently associated with a higher post-surgery DVT risk in primary KOA patients. It is necessary to optimize prophylaxis strategies for DVT in these patients.