Genomic characterization and biological activities of cell-free supernatant from Lactiplantibacillus pentosus CROT01 against clarithromycin-resistant Helicobacter pylori.

Helicobacter pylori is a major gastric pathogen associated with chronic gastritis, peptic ulcers, and gastric cancer, while increasing antibiotic resistance has reduced the effectiveness of standard eradication therapies. This study investigated the antibacterial, antibiofilm, anti-inflammatory, probiotic-related, and genomic properties of cell-free supernatant (LCFS) derived from Lactiplantibacillus pentosus CROT01 against H. pylori. LCFS exhibited inhibitory activity against all tested H. pylori strains, including the clarithromycin-resistant strain ATCC 700684, with inhibition zones ranging from 10.67 ± 0.58 to 17.33 ± 1.53 mm. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) ranged from 12.5-50 mg/mL and 25-50 mg/mL, respectively. LCFS significantly inhibited biofilm formation and eradicated established H. pylori biofilms. Scanning electron microscopy revealed marked morphological alterations in treated cells, including membrane disruption, deformation, and cellular shrinkage. Anti-inflammatory activity was demonstrated through suppression of nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 cells. In addition, L. pentosus CROT01 exhibited tolerance to acidic pH and pancreatin, high cell surface hydrophobicity, and moderate adhesion ability toward Caco-2 cells. Whole-genome sequencing identified several bacteriocin-associated genes, including plantaricin E, plantaricin F, pediocin, enterolysin A, and bovicin-related peptides, whereas no virulence-associated or acquired antimicrobial resistance genes were detected. Thus, these findings suggest that LCFS derived from L. pentosus CROT01 possesses promising anti-H. pylori activity and may represent a potential postbiotic-based strategy against antibiotic-resistant H. pylori infection.