Protective Effects of Lactobacillus ‐Derived Probiotics and Postbiotics on Renal and Reproductive Function in Escherichia coli –Infected Rats

BACKGROUND: Escherichia coli infections of the genitourinary tract are a major cause of renal and reproductive dysfunction in males, often impairing spermatogenesis and fertility. Probiotics and postbiotics have emerged as microbiota‑based interventions with strain‑specific immunomodulatory and antioxidant properties. OBJECTIVES: This experimental study evaluated the effects of a probiotic or postbiotic supplementation containing Lactobacillus helveticus, Lactobacillus rhamnosus, and Lactobacillus casei on renal and testicular tissues, as well as sperm parameters, in male Wistar rats infected with E. coli. METHODS: CFU/mL). Probiotic or postbiotic supplementation was administered orally (gavage) once daily for 35 consecutive days, starting immediately after the final day of bacterial challenge. Biochemical markers (urea, creatinine, sodium, potassium), histological changes, total antioxidant capacity (TAC), gene expression (IL‑6, TNF‑α, Bax, Bcl‑2), and sperm quality were assessed. Statistical analysis was performed using one‑way ANOVA with Tukey's post hoc test (p < 0.05). RESULTS: E. coli infection significantly impaired renal and testicular histology, elevated pro‑inflammatory and pro‑apoptotic gene expression, reduced TAC, and deteriorated sperm parameters. Probiotic and postbiotic supplementation mitigated these effects, restoring antioxidant capacity, enhancing Bcl‑2 expression, reducing IL‑6 and TNF‑α levels, and improving sperm viability and morphology. Histological evaluation confirmed partial recovery of kidney and testicular structures in treated groups. CONCLUSION: Multi‑strain probiotic-postbiotic mixtures confer protective effects against infection‑induced oxidative stress, apoptosis, and inflammation in renal and testicular tissues, while improving sperm quality. These findings highlight their translational potential as adjunctive therapies for infection‑associated male infertility and renal impairment.