Given the importance of effective treatments with fewer side effects using the anti-inflammatory and immunomodulatory properties of probiotics, this study aimed to examine the role of oral administration of probiotic on hyperalgesia, edema, IL-1β serum level, spinal p38MAPK activity, and MOR expression during different stages of adjuvant-induced arthritis in male Wistar rats. The gene discussed is OPRM1; the disease is arthritic joint disease.