Strain-specific effects of probiotic Lactobacilli on mRNA expression of epigenetic modifiers in intestinal epithelial cells.

The epigenome of an organism is as important as the genome for the normal development and functioning of an individual. The human epigenome can be affected by various environmental factors including nutrients, microbiota and probiotics through epigenetic modifiers and mediates various health-promoting effects. The present study was aimed to explore the temporal changes in DNA and histone modifiers (DNMT1, TET2, p300, HDAC1, KMT2A, KDM5B, EzH2 and JMJD3) in intestinal epithelial cells (Caco-2) by probiotic lactobacilli (Limosilactobacillus fermentum MTCC 5898 and Lacticaseibacillus rhamnosus MTCC 5897) in comparison to opportunistic commensal pathogen Escherichia coli (ATCC 14849). Cells were treated separately with probiotic strains and E. coli for different durations and temporal changes in gene expression among DNA and histone modifiers were measured. Time-dependent studies showed that L. fermentum enhanced the transcription of epigenetic modifiers at 12 h of treatment (P < 0.05) contrary to E. coli which reduced the expression of these genes during the same duration of treatment. On the other hand, probiotic L. rhamnosus was not able to induce any significant changes in gene expression of these modifiers. Furthermore, during the exclusion of E. coli by L. fermentum, the probiotic was found to resist the changes made by E. coli in the transcription of some of the epigenetic modifiers. Thus, it is concluded that the probiotics modulated the mRNA expression of DNA and histone modifiers contrarily to E. coli in a strain-specific manner.