Hyperuricemia is the increased serum uric acid concentration, associated with metabolic syndrome that commonly leads to heart disease, gout, and chronic nephropathy. In animals, uric acid can be oxidized by the uricase enzyme and excreted in the urine. Unfortunately, humans lack uricase. This study aimed to find uricase-producing probiotic lactobacilli. L. plantarum KU985438 and L. rhamnosus KU985439 were selected to produce functional fermented yogurts. Induced-hyperuricemic animal models were used to test the yogurts' hypouricemic, anti-inflammatory, and antioxidant effects. Male Wistar rats fed probiotics orally for seven days showed decreased levels of uric acid and ankle edema in the therapeutic and protective groups compared to the control (indomethacin-treated). The two yogurts also reduced TNF-α, IL-1β, and NF-kB concentrations in inflamed joints by decreasing oxidative stress. Histopathology showed arthritis rats with abnormalities, deformities, necrosis, and edema in their joints. In the protective group, the synovial membrane and articular surface were nearly normal with the administration of the two yogurts concurrently with hyperuricemia induction. In the therapeutic group, retrieval from hyperuricemia was observed after 7 days of probiotic administration. Immuno-staining of the reactive immune cells (iNOS) in arthritic rats showed high expression levels. Both conventional medicine and yogurts reduced immune-reactive cell activity in arthritis-affected rats. To the authors’ knowledge, this study is considered the first to explore the efficacy of lactobacilli on the reactive immune cell expression in arthritic rats. In conclusion, L. plantarum and L. rhamnosus, with potent therapeutic and protective efficacy against MSU-induced arthritis, could be used as functional food supplements.