Abstract
Knee osteoarthritis (OA) is a prevalent degenerative joint disease among middle-aged and older adults, leading to chronic pain, functional limitations, and decreased quality of life. While probiotics have shown anti-inflammatory potential in preclinical studies, their therapeutic role in OA has not been well established in human research. This exploratory randomized controlled trial (RCT) aimed to evaluate the efficacy and safety of Latilactobacillus sakei LB-P12 in improving knee OA symptoms. In this randomized, double-blind, placebo-controlled trial, 100 participants aged 40-75 years with chronic knee pain were assigned to receive either LB-P12 (350 mg/day, 10 billion CFU) or placebo for 12 weeks. The primary outcome was the change in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores. Secondary outcomes included visual analog scale (VAS) scores for pain, inflammatory markers (CRP, ESR, IL-1β, IL-6, TNF-α), cartilage degradation biomarkers (COMP), joint space width, and health-related quality of life (EQ-5D-5L). Safety was evaluated using laboratory tests and vital signs. After 12 weeks, the LB-P12 group showed significantly greater improvements in WOMAC total scores and VAS pain scores compared to the placebo group. All three WOMAC subdomains-pain, stiffness, and physical function-showed consistent reductions. Inflammatory cytokines, particularly IL-1β, were significantly reduced in the LB-P12 group. Quality of life also improved significantly. No adverse events or clinically meaningful abnormalities in laboratory values were observed. This exploratory RCT suggests that daily supplementation with LB-P12 is safe and may offer potential benefits in reducing knee pain and improving physical function and quality of life in individuals with knee OA. Further large-scale and long-term RCTs are needed to confirm these findings and elucidate the underlying mechanisms.