Efficacy of Lacticaseibacillus rhamnosus probiotic strains in treating chromate induced dermatitis

Chromate induced dermatitis is a significant occupational health concern. Chromate (Cr) resistant Lacticaseibacillus rhamnosus strains were isolated from commercial probiotic sachets PREPRO and HiFLORA. Among 13 Cr-resistant bacterial isolates, six were selected based on high chromate resistance at 500 ug/ml. Selected isolates were subjected to biochemical and molecular characterization and in vivo analyses. DPC assay was conducted under controlled conditions in order to determine the reduction potential of the isolated bacteria. The selected isolates were identified as L. rhamnosus-L1 (PP493917), L. rhamnosus-L2 (PP493918), L. rhamnosus-L3 (PP493921) L. rhamnosus-L4 (PP493920) L. rhamnosus-L8 (PP493922) and L. rhamnosus-L12 (PP493923). Lacticaseibacillus rhamnosus L1showed highest resistance against Cr (VI) with reduction potential 56%. In vivo experiments were performed to assess the healing effects of isolated bacterial strains on mice skin, with Hematoxylin and Eosin (H&E) staining used to identify severe dermatitis in skin tissue and evaluate therapeutic effects of probiotic strains. The structural determination of flavin reductase protein of L. rhamnosus was carried out using bioinformatics tools. These tools predicted the structural-based functional homology of flavin reductase protein in bacterial Cr (VI)-detoxification system. Lacticaseibacillus rhamnosus can be effectively used against chromate-induced dermatitis due to its high chromate resistance and reduction potential.