Abstract
Limosilactobacillus reuteri is a promising probiotic species, yet strain-specific properties must be thoroughly characterized to ensure safety and efficacy. In this study, we isolated L. reuteri MKLQ3807-13 from the feces of a healthy Kunming dog and evaluated its probiotic potential through integrated genomic and phenotypic analyses. Whole-genome sequencing revealed that MKLQ3807-13 possessed a single 2.05 Mb circular chromosome, lacked plasmids, and harbored genes associated with acid and bile tolerance, adhesion, antimicrobial production, antioxidant activity, and γ-aminobutyric acid (GABA) biosynthesis. Phenotypic characterization showed that MKLQ3807-13 exhibited strong tolerance to acidic conditions (88.21% survival at pH 2.0) and bile salts (96.43% survival at 0.3%), high cell-surface hydrophobicity (76.28%), strong adhesion to HT-29 cells (18.71%), and substantial co-aggregation with Escherichia coli K88, Salmonella Typhi, Staphylococcus aureus ATCC 49,521, and Listeria monocytogenes BNCC 336,877. The strain demonstrated a broad spectrum of antimicrobial activity, attributed to organic acid production and a putative bacteriocin gene cluster, along with extracellular antioxidant activity. Furthermore, MKLQ3807-13 produced GABA in a time-dependent manner, reaching 36.36 µmol/mL after 48 h. Notably, safety evaluations showed no hemolytic activity, an absence of biogenic amine production, and no detectable virulence or horizontally transferable antibiotic resistance genes. These comprehensive findings indicate that L. reuteri MKLQ3807-13 possesses desirable probiotic attributes and a favorable safety profile, supporting its potential as a functional probiotic candidate for canines and other hosts.Supplementary information
The online version contains supplementary material available at https://doi.org/10.1007/s13205-026-05070-w.