Eubacterium limosum El1405 demonstrates strong safety profile and protects mice against Salmonella Typhimurium infection

The escalating crisis of antibiotic resistance, particularly with pathogens like Salmonella Typhimurium, necessitates the urgent development of alternative therapeutic strategies. Current treatments often face challenges due to resistance mechanisms, leading to prolonged illness and increased mortality. Probiotic strains offer a promising avenue, leveraging beneficial microbes to modulate gut health and combat infections. Eubacterium limosum El1405 is a novel probiotic candidate, previously noted for its anti-inflammatory and anti-tumor properties, but its comprehensive safety and specific protective effects against bacterial pathogens like S. Typhimurium required systematic evaluation.

Researchers assessed the safety of E. limosum El1405 through in vitro hemolytic and gelatinase assays. For in vivo safety, a 28-day subchronic oral toxicity mouse model was employed, where mice received El1405 at low, medium, and high doses. Key endpoints included body weight, visceral index, organ histopathology, hematological profiles, serum biochemistry, and cytokine levels. Antibacterial activity against pathogenic bacteria was determined in vitro. Finally, a Salmonella Typhimurium-infected mouse model was used to evaluate the protective effects of El1405 intervention against infection.

In in vitro safety assessments, Eubacterium limosum El1405 demonstrated no hemolytic or gelatinase activity, confirming its basic safety profile. The 28-day subchronic oral toxicity test in mice, using low, medium, and high doses of El1405, revealed no significant alterations in mouse body weight, visceral index, organ histopathology, hematological parameters, serum biochemistry, or cytokine levels, indicating a favorable safety profile in vivo. The strain also exhibited direct antibacterial activity against S. Typhimurium in vitro.