Bacillus velezensis MFF 2.2-derived lipopeptides modulate gut immune response in BALB/c mice maintaining mucosal integrity and systemic safety.

Bacillus-derived lipopeptides, particularly surfactin (SF), are known for their antimicrobial and immunomodulatory properties, making them promising candidates for applications in veterinary medicine. This study investigated the immunomodulatory, cytotoxic, and genotoxic effects of a lipopeptide extract (LPE) derived from Bacillus velezensis MFF 2.2, containing SF, using an in vivo murine model. Four groups of BALB/c mice (n = 6 per group) were orally administered daily doses of: (1) saline solution (control), (2) 60 μg/mL SF standard, (3) 40 μg/mL LPE, and (4) 60 μg/mL LPE, over a 10-day period. Assessments included changes in body weight, histopathological analysis of liver, kidney, and small intestine tissues, as well as evaluation of cytotoxic and genotoxic effects. LPE treatment was well-tolerated, with no significant changes in body weight, organ histopathology, or bone marrow toxicity. Both SF and LPE significantly increased goblet cell counts (P < 0.05), while LPE reduced IFN-γ levels and increased the IL- 10/IFN-γ ratio, suggesting an anti-inflammatory response (P < 0.05). TNF-α and IL- 10 levels remained unchanged, and no significant differences were observed in intraepithelial lymphocyte counts. These findings suggest that LPE derived from B. velezensis MFF 2.2 is safe and promotes immunomodulatory effects, supporting its potential as a therapeutic agent in inflammatory conditions.