Novel Lactobacillus Strains Alleviate E. coli-induced Inflammation in a Urinary Tract Infection Rat Model

Urinary tract infections (UTIs) are common bacterial infections that are predominantly caused by uropathogenic Escherichia coli. Chronic recurrence of UTIs, particularly in women, seriously affects the quality of life of infected individuals. Antibiotics are still the first-line treatment for UTIs; however, side effects and increasing antibiotic resistance emphasize the need for alternative therapies. In this study, we explored the in vitro and in vivo anti-E. coli effects of heat-inactivated Lactobacillus helveticus GUT10, L. salivarius HHuMin-U, and their combination. In lipopolysaccharide (LPS)-induced human urinary bladder cancer T24 cells, all probiotic treatments suppressed the expression of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6), cyclooxygenase 2 (COX2), and prostaglandin E2 (PGE2) by inhibiting the upregulation of NF-κB signaling and the production of reactive oxygen species (ROS). In an E. coli-induced UTI rat model, a significant alleviation of damage to the bladder and urethral mucosa by the two Lactobacillus strains in protective and treatment studies was accompanied by a decrease in the E. coli load in the bladder and urine and an increase in lactobacilli in the bladder. Thus, the probiotic mixture has potent protective and therapeutic effects and shows promise as a nonantibiotic approach for UTI treatment.