Antioxidant profiling and molecular characterization of novel Lacticaseibacillus rhamnosus strains isolated from human microbiota

Purpose: To assess the antioxidant properties of two newly isolated Lacticaseibacillus rhamnosus strains (BVV1 and BBV2) from breastfed infants for potential use in nutritional and probiotic formulations. Methods: Strains were identified using the Basic Local Alignment Search Tool (BLAST) with the National Center for Biotechnology Information (NCBI) 16S database. The in vitro antioxidant activities were assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical scavenging ability, Fe²⁺ chelation, lipid peroxidation inhibition, and superoxide anion reduction compared to L. rhamnosus GG. Results: The BBV2 exhibited the highest DPPH scavenging (82.44 ± 1.87 %) and Fe²⁺ chelation (71.72 ± 2.78 %). Hydroxyl radical scavenging was strongest in GG (83.12 ± 2.59 %) than in BBV2 (79.59 ± 4.49 %). Lipid peroxidation inhibition in GG (63.44 ± 4.66 %) was higher than in BBV2 (58.24 ± 1.38 %). Conclusion: BBV2 shows strong antioxidant potential, making it a promising natural alternative to synthetic antioxidants in probiotic and nutritional applications.