Effects of probiotics on clinical manifestations and inflammatory markers in HTLV-1-associated myelopathy/tropical spastic paraparesis: A triple blind randomized, placebo controlled trial.

Human T-lymphotropic virus type 1 (HTLV-1), leads to adult T-cell lymphoma/leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in a minority of infected individuals. The virus promotes inflammation, a major factor in chronic disease progression. Probiotics' immune modulation and anti-inflammatory effects present a potential therapeutic intervention for HTLV-1-related conditions. This study investigates the impact of probiotics on both clinical manifestations and inflammatory markers in HAM/TSP patients. Conducted at the HTLV-1 clinic of Ghaem Hospital (Mashhad, Iran) between 2019 and 2020, this study randomized 40 HAM/TSP patients into two groups: an intervention group receiving 500 mg LactoCare capsules twice daily and a control group receiving placebo capsules of identical appearance for 12 weeks. Baseline and follow-up assessments included muscle strength, spasticity, motor disability, urinary disturbance, and serum levels of IL-10, IL-4, and IFN-γ (measured by ELISA). Post-intervention analysis revealed no significant differences between intervention and control groups in muscle strength, spasticity, and motor disability. However, significant improvement was observed in the intervention group regarding urinary symptoms after 12 weeks of initiation of intervention (P = 0.003). No significant changes were detected in serum levels of IL-10, IL-4, and IFN-γ between the two groups. The probiotics showed positive effects on urinary symptoms in HTLV-1-associated myelopathy/tropical spastic paraparesis patients but did not significantly impact other clinical or paraclinical parameters within the 12-week study period. These findings suggest that probiotics may offer symptomatic relief for some symptoms of HTLV-1-associated myelopathy/tropical spastic paraparesis patients.