Exploring the probiotic potential of Agrilactobacillus fermenti from a canine feces: Functional and genomic insights beyond fermented vegetable applications

Abstract

Addressing the growing demand for species-specific probiotics in functional food development, this study presents the first comprehensive characterization of Agrilactobacillus fermenti Pom1, a novel strain isolated from canine feces, a source chosen due to its potential to harbor host-adapted beneficial bacteria. To evaluate its probiotic potential and safety, a series of in vitro assays, including a Caco-2 adhesion assay, and whole-genome sequencing using the BGISEQ-500 platform were performed. A. fermenti Pom1 exhibited key probiotic traits in vitro, including a high adhesion rate to Caco-2 cells (87.63 %), indicating strong potential for intestinal colonization and gut health promotion. Using the DPPH assay, A. fermenti Pom1 demonstrated moderate antioxidant activity (16.74 %), which, while lower than that of ascorbic acid (93.70 %), may still contribute to gut health by mitigating oxidative stress within the intestinal environment, consistent with the strain-dependent nature of antioxidant production in lactic acid bacteria. Pom1 also showed notable cell surface hydrophobicity and auto-aggregation—critical features for gastrointestinal persistence. Whole-genome sequencing of its 2.56 Mb circular chromosome revealed 2,618 genes, including those potentially involved in the biosynthesis of essential B-vitamins, amino acids, and short-chain fatty acids, suggesting significant potential for in situ nutrient production. Genes linked to sortase A (srtA) and exopolysaccharide production suggest advanced mechanisms for host interaction and gut barrier modulation. Importantly, safety assessments confirmed the absence of virulence factors, antibiotic resistance genes, and cytotoxicity, aligning with food safety standards for probiotic use. These findings highlight the high adhesion rate of A. fermenti Pom1 and its promising metabolic capabilities, alongside a moderate level of antioxidant activity that may still be beneficial in the gut. This positions A. fermenti Pom1 as a promising candidate for incorporation into functional pet food formulations, contributing to improved companion animal nutrition and health while advancing innovation at the intersection of agriculture and food.