Lactobacillusreuteri protects against heat stress-induced testicular dysfunction by modulating oxidative stress and autophagy pathways in rats

Abstract

Objective: To investigate the potential of Lactobacillus reuteri (Lr) in ameliorating heat stress (HS)-induced testicular damage through modulation of oxidative stress and autophagy.

Design: Experimental controlled study involving adult male Wistar rats exposed to HS and/or probiotic treatment.

Subjects: Adult male Wistar rats divided into six groups: control, Lr-only (LrP-sole), HS-only (37 °C and 40 °C), and Lr-treated HS groups.

Intervention: Heat stress was induced by immersing the scrotal area in a water bath at 37 °C or 40 °C for 20 minutes daily over 42 days. Lactobacillus reuteri probiotic (5 × 10⁸ CFU/mL) was administered orally throughout the experimental period.

Main outcome measures: Sperm count, motility, viability, nuclear maturity, and deoxyribonucleic acid integrity; testicular histopathology; total antioxidant capacity and total oxidant status; expression of autophagy-related genes (p62, Atg7, Beclin-1, and LC3-I) by quantitative reverse transcriptase polymerase chain reaction; and LC3-I/II protein levels by immunohistochemistry.

Results: Heat stress significantly impaired spermatogenesis, spermiogenesis, and sperm quality, with elevated oxidative and autophagic stress, particularly at 40 °C. L. reuteri probiotic treatment significantly improved sperm parameters, restored spermatogenic activity, reduced total oxidant status, and enhanced antioxidant capacity. Moreover, Lr modulated the expression of p62, Atg7, Beclin-1, and LC3-I/II, indicating regulation of autophagic pathways and mitigation of oxidative stress within the testicular microenvironment.

Conclusion: Lactobacillus reuteri confers robust protection against HS-induced testicular dysfunction, likely through modulation of oxidative stress and autophagy. These findings highlight the therapeutic potential of probiotics as a noninvasive intervention to counteract heat-induced male infertility.

Keywords: Autophagy; Lactobacillus reuteri; heat stress; oxidative stress; spermatogenesis.