Systematic functional, genomic, and safety evaluation of food-derived anti-human norovirus candidate Lacticaseibacillus rhamnosus YQ001

Lacticaseibacillus rhamnosus YQ001 is a yogurt-derived strain previously reported to bind GII.4 human norovirus (HuNoV) and inhibit viral replication in zebrafish larvae. Here, its in vitro probiotic properties and preliminary safety were evaluated together with whole-genome analysis. The 2.87-Mb genome (46.67% GC; 2757 coding sequences) shared 97.66% average nucleotide identity with L. rhamnosus GG ATCC 53103. L. rhamnosus YQ001 showed acid and bile tolerance, retaining approximately 30% survival after 3 h at pH 2.0 and over 40% after 4 h in 0.2% bile salts. During sequential simulated gastrointestinal digestion, L. rhamnosus YQ001 retained 35.98% survival after the gastric phase and 45.06% after the intestinal phase. L. rhamnosus YQ001 showed over 90% auto-aggregation at 24 h, while its cell-free supernatant exhibited DPPH and ABTS radical-scavenging activities of 85.17% and 76.35%, respectively. Antibacterial activity detected by agar diffusion was abolished after pH neutralization, indicating that the observed inhibition was largely pH-dependent under the tested conditions. L. rhamnosus YQ001 was non-hemolytic and negative for gelatinase and nitroreductase activities. Overall, the phenotypic and genomic findings support the probiotic potential of L. rhamnosus YQ001, while further strain-specific functional and safety evaluation is warranted.