A daily fiber supplement reduced knee arthritis pain and improved strength
Get the Culture newsletter
Daily culture — film, music, books, the trends and ideas worth your attention. Free.
- University of Nottingham researchers ran the INSPIRE randomized controlled trial with 117 adults with knee osteoarthritis over six weeks, testing inulin alone, digital physiotherapy alone, both combined, and a placebo.
- Inulin — a prebiotic fiber found in chicory root and Jerusalem artichokes — reduced knee pain, and only the inulin group uniquely showed improved grip strength and lower pain sensitivity.
- Digital physiotherapy also cut knee pain independently, but the inulin arm had a 3.6% dropout rate compared with 21% in the exercise-only arm.
- Inulin participants showed higher blood levels of butyrate and the gut hormone GLP-1, and elevated GLP-1 correlated with better grip strength — a finding the authors call a possible gut-muscle-pain axis.
- Dr. Afroditi Kouraki, lead author from Nottingham's School of Medicine, called the result "exciting" and pitched adding inulin to breakfast or yogurt as a simple change patients could sustain.
- Professor Ana Valdes, senior author, said the GLP-1–grip strength link "warrants further investigation" with potential implications for ageing and physical resilience beyond osteoarthritis.
- Arthritis UK Director of Research Professor Lucy Donaldson endorsed the findings, citing a lived-experience survey showing six in ten people with arthritis live in pain most or all of the time.
- The study was published in the journal Nutrients (DOI: 10.3390/nu18050714).
Why it matters: Knee osteoarthritis affects hundreds of millions worldwide, and current management leans on painkillers with side effects or exercise programs many patients abandon. A cheap, tolerable fiber supplement that matches physiotherapy for pain relief while cutting dropout nearly six-fold could shift first-line self-management — though the 117-person, six-week trial needs larger replication before clinical guidelines move.
