Background

Osteoarthritis (OA) is a painful chronic condition where articular cartilage degenerates over time, resulting in loss of function and progressive disability. Obesity is a primary risk factor for the development and progression of knee OA, defined as “metabolic OA phenotype”. Metabolic OA is associated with increased fat deposits that release inflammatory cytokines/adipokines, thereby causing systemic and local (knee) inflammation, contributing to cartilage degeneration. There is currently no cure for OA. Prebiotics are a type of dietary fiber that have been shown to positively influence gut microbiota thereby reducing inflammation and offering cartilage protection in mice. However, there are no human clinical trials to test the effects of prebiotics in adults with obesity suffering metabolic knee OA. Therefore, the purpose of the study is to determine if prebiotic supplementation can, through changes in the gut microbiota, improve knee function and physical performance in adults with obesity with metabolic knee OA.

Methods

Twenty-two adults with obesity suffering from knee OA were randomized to prebiotic supplement (n=12, 1 ♂, 60±9 years, BMI=35.2±5.6 kg/m2, inulin/oligofructose; 15g/day) or placebo (n=10, 1 ♂, 60±11 years, BMI=34.4±6.7 kg/m2) for 3 months. The following performance-based tests were assessed at baseline and at 3 months following the diet intervention: 30s chair stand, 40m fast-paced walk, timed up & go, hand grip strength, and 6-minute walk

Results

There was a significant improvement in performance-based tests (except the 6-minute walk test) from baseline to 3 months in the prebiotic, but no improvement was observed in the placebo group.

Conclusions

Therefore, a prebiotic diet intervention might represent an alternative inexpensive and easy to adhere treatment to improve knee joint function in adults with obesity suffering from metabolic knee OA. Examination of gut microbiota and inflammatory changes is warranted.