# Genomic and Metabolomic Insights Into the Probiotic Potential of Weissella viridescens

## TL;DR

This study explores the probiotic potential of Weissella viridescens Wv2365 by analyzing its genome and metabolism, finding it safe and capable of surviving in the gut.

## Contribution

The study provides the first strain-level multi-omics characterization of W. viridescens for probiotic potential.

## Key findings

- Wv2365 tolerates acidic and bile conditions, suggesting gastrointestinal survival.
- The strain exhibits antioxidant activity and cell aggregation, supporting probiotic function.
- No acquired antibiotic resistance or virulence genes were detected, indicating safety.

## Abstract

Weissella viridescens is a lactic acid bacterium that has been detected in fermented foods and the human intestinal tract, yet its probiotic potential remains poorly characterized at the strain level. In this study, we performed an integrated genomic, metabolomic, and phenotypic evaluation of a human-gut-derived strain, W. viridescens Wv2365. We found that this strain has metabolic characteristics related to carbohydrate and amino acid utilization, can tolerate acidic and bile conditions relevant to the gastrointestinal environment, and exhibits cell aggregation and antioxidant activity. Safety assessments did not indicate the presence of acquired antibiotic resistance or virulence-related traits. Overall, these findings suggest that Wv2365 is safe as a potential probiotic.

Weissella viridescens has been proposed as a probiotic candidate, but strain-level multi-omics evidence remains limited. The complete genome of the human-derived W. viridescens strain Wv2365 was sequenced through a hybrid assembly of Illumina and PacBio sequencing reads and compared with eight publicly available W. viridescens genomes. Pangenome analysis and functional annotation were performed, and metabolites were profiled by broadly targeted metabolomic analysis. In addition, the acid and bile tolerance, auto-aggregation and cell surface hydrophobicity, and antioxidant activity of the strain, as well as both in silico and phenotypic safety, were assessed. Wv2365 carries a single chromosome of 1.57 Mb with 41.3% G+C content. The species has an open pangenome with 803 core genes. Genomic and metabolomic features converged on carbohydrate and amino acid metabolism, including glycolysis/tricarboxylic acid (TCA) cycle and arginine pathways, and a carbohydrate-active enzyme (CAZyme) repertoire dominated by glycosyltransferases. In vitro, Wv2365 tolerated pH 3.0 and 0.3% bile, showed auto-aggregation, surface hydrophobicity, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical scavenging. The strain was susceptible to 10 antibiotics tested except for its intrinsic vancomycin non-susceptibility and was non-hemolytic and gelatinase negative. No acquired antimicrobial resistance or virulence genes were found in the genome. These findings indicate that W. viridescens Wv2365 is safe with probiotic traits relevant to gastrointestinal survival, colonization, and redox balance.