Inulin Supplementation for Reducing Inflammation and Knee Pain in Older Adults With Osteoarthritis

Inclusion Criteria: * Provision of signed and dated informed consent form. * Stated willingness to comply with all study procedures and availability for the duration of the study (8 weeks). * Male or female, aged ≥ 40 years. * Established patient in the VA Connecticut Healthcare System * At least one knee with pain severity in the past week ≥ 4/10 on numerical rating scale (NRS) * Self-reported knee pain on most days of the prior month. * Diagnosed with knee osteoarthritis (Kellgren-Lawrence grade 2-4 on radiographic imaging within the past 2 years). * Ability to take oral powder supplements and willingness to adhere to the inulin/placebo daily regimen. * Agreement to adhere to lifestyle considerations (see Section 5.3) throughout study duration, including maintenance of current diet, physical activity, and avoidance of new dietary supplements or complementary therapies. * English-speaking and able to provide informed consent. * For females of reproductive potential: use of highly effective contraception for at least 1 month prior to screening and agreement to continue such method during study participation. Exclusion Criteria: * Current diagnosis of pre-diabetes (impaired glucose tolerance) or diabetes mellitus (Type 1 or Type 2). * Use of antibiotics within the past 6 months. * Current use of medications known to significantly impact the gut microbiome (e.g., proton pump inhibitors, disease-modifying antirheumatic drugs, GLP-1 receptor agonists). * Use of anti-inflammatory dietary supplements (e.g., turmeric, omega-3 fatty acids) within the past 30 days. * Participation in another interventional study or use of an investigational drug within the past 30 days. * Current use of complementary or integrative therapies for knee OA including tai chi, acupuncture or yoga. * Known allergy or intolerance to components of the study intervention, including inulin or maltodextrin. * The presence of significant gastrointestinal disease that may interfere with the intervention or outcomes, such as inflammatory bowel disease or active peptic ulcer disease. * Any medical, psychological, or behavioral condition that, in the opinion of the investigators, would place the participant at undue risk, interfere with study participation or adherence, or compromise data integrity. * Current diagnosis of alcohol use disorder * Pregnancy