Protective Effect of Bifidobacterium longum subsp. infantis E4 Exopolysaccharide on Intestinal Barrier, Regulation of Gut Microbiota and Metabolite In Vitro, and Immunosuppressed Mice.

EPS-1 and EPS-2 from B. infantis E4 promoted survival rates and wound healing rates in IEC-6 intestinal epithelial cells.

• Both EPS-1 and EPS-2 were generated by Bifidobacterium longum subsp. infantis E4
• Cell survival rates were increased following EPS-1 and EPS-2 treatment in IEC-6 cells
• Wound healing rates were improved in EPS-treated IEC-6 cells
• These effects were observed in an in vitro intestinal barrier model

EPS-1 and EPS-2 enhanced intestinal barrier integrity in IEC-6 cells as measured by transepithelial electrical resistance (TEER) values and paracellular permeability.

• Transepithelial electrical resistance (TEER) values were increased with EPS-1 and EPS-2 treatment
• Paracellular permeability of IEC-6 cells was reduced by EPS-1 and EPS-2
• mRNA levels of tight junction proteins (TJs) were upregulated in EPS-treated cells
• These findings indicate a strengthening of the epithelial barrier function

EPS-1 and EPS-2 mitigated intestinal histological lesions and improved villus morphology in immunosuppressed mice.

• EPS-1 and EPS-2 mitigated intestinal histological lesions relative to the model group
• Enhanced ileal villus length/crypt depth ratios were observed in EPS-treated mice
• mRNA levels of Muc2 were increased relative to the model group
• mRNA levels of tight junction proteins (TJs) were also increased relative to the model group
• Effects were studied in an in vivo immunosuppressed mouse model

EPS-1 and EPS-2 treatment increased levels of immune cells including IgA, dendritic cells, T cells, and B cells in immunosuppressed mice.

• Levels of IgA were increased following EPS-1 and EPS-2 treatment
• Dendritic cell levels were elevated in EPS-treated mice
• T cell subpopulations including CD3+, CD4+, and CD8+ cells were increased
• B cell levels were also increased relative to the model group
• These findings indicate an immunomodulatory effect of the exopolysaccharides

EPS-1 and EPS-2 from B. infantis E4 regulated gut microbiota composition and metabolites in immunosuppressed mice.

• Both EPS-1 and EPS-2 modulated gut microbiota in mice
• Metabolite profiles were also regulated by EPS-1 and EPS-2 treatment
• These effects were observed in the in vivo immunosuppressed mouse model
• Regulation of gut microbiota and metabolites was identified as a mechanism through which EPSs may influence organismal health