The current study aims to evaluate the effectiveness of adding probiotics to the standard of care in improving OA patient-related outcomes such as pain, stiffness, and physical activity.

Osteoarthritis (OA) is a severe progressive chronic arthropathy causing articular remodeling and inflammation of synovial tissue. The disease involves the entire synovial joint, including the cartilage, joint lining, and subchondral bone. OA causes pain, swelling, and stiffness, consequently hindering the patient's ability to perform their main daily activities, which often leads to social isolation and depression. Up till now, there is no cure for OA treatment options target either symptomatic relief (mainly pain) such as acetaminophen, glucosamine, chondroitin sulfate, and non-steroidal anti-inflammatory drugs (NSAIDs) or structure repair.

Probiotics are live and active microorganisms widely known as the gut's beneficial bacteria. They are taken to alter the GI flora and provide health benefits such as achieving optimal digestion and immunological function.

Inclusion Criteria:

Patients (both sexes) aged above 18 years who met the American College of Rheumatology (ACR) clinical criteria for KOA [7] and had symptomatic OA of at least one knee (index knee).

Exclusion Criteria:

1. Rheumatoid arthritis or other active generalized inflammatory comorbidities affecting the gastrointestinal tract (IBD, celiac disease)
2. Performed a total knee replacement on the affected knee or the waiting list for joint replacement
3. surgeries (such as gastric bypass) or Other concomitant injuries can override OA symptoms or interfere with physical activity.
4. Malabsorption disorders, systemic organ failure (liver, renal, cardiac)
5. Use corticosteroids with doses above 10 mg/day or Intra-articular injections during the previous 6 months.
6. Recent antibiotic treatment (i.e., <2 months before the beginning of the study).
7. Pregnancy/breastfeeding
8. Participants who smoked more than 10 cigarettes per day were excluded.
9. Immunosuppressive treatment or impaired immune system
10. Chronic or acute diarrhea
11. Blood/plasma donation/transfusion during the 3 months of the study
12. Non-controlled diabetes
13. Allergy with regards to any of the study product ingredients.
14. Post-traumatic OA (e.g., fractures), congenital hip deformities, or degenerative or non-degenerative neurological conditions can alter pain perception.

outcome assessors were blinded to participant data. the researcher coded patient data before analysis