Bifidobacterium breve UCC2003 Exopolysaccharide Modulates the Early Life Microbiota by Acting as a Potential Dietary Substrate

Abstract

Background: Bifidobacterium represents an important early life microbiota member. Specific bifidobacterial components, exopolysaccharides (EPS), positively modulate host responses, with purified EPS also suggested to impact microbe–microbe interactions by acting as a nutrient substrate. Thus, we determined the longitudinal effects of bifidobacterial EPS on microbial communities and metabolite profiles using an infant model colon system. Methods: Differential gene expression and growth characteristics were determined for each strain; Bifidobacterium breve UCC2003 and corresponding isogenic EPS-deletion mutant (B. breve UCC2003del). Model colon vessels were inoculated with B. breve and microbiome dynamics monitored using 16S rRNA sequencing and metabolomics (NMR). Results: Transcriptomics of EPS mutant vs. B. breve UCC2003 highlighted discrete differential gene expression (e.g., eps biosynthetic cluster), though overall growth dynamics between strains were unaffected. The EPS-positive vessel had significant shifts in microbiome and metabolite profiles until study end (405 h); with increases of Tyzzerella and Faecalibacterium, and short-chain fatty acids, with further correlations between taxa and metabolites which were not observed within the EPS-negative vessel. Conclusions: These data indicate that B. breve UCC2003 EPS is potentially metabolized by infant microbiota members, leading to differential microbial metabolism and altered metabolite by-products. Overall, these findings may allow development of EPS-specific strategies to promote infant health.

Exploring the Genomic Diversity and Antimicrobial Susceptibility of Bifidobacterium pseudocatenulatum in a Vietnamese Population

“…For example, high-molecular-weight EPS is more likely to induce weaker immune responses, potentially because these encapsulating structures shield the complex protein antigens on the bacterial surface from interaction with immune cells ( 51 ). Furthermore, a specific EPS from B. breve has been shown to be metabolized by some members of the infant gut microbiota, indicating that EPS further facilitates cross-feedings between gut bacteria ( 52 ). Therefore, the considerable diversity shown by different EPS genomic characterizations in our B .…”

Microbiota and Cancer: The Emerging Beneficial Role of Bifidobacteria in Cancer Immunotherapy

“…One cluster (epsRhm) was found to include genes that are putatively responsible for rhamnose biosynthesis, whereas the second cluster (eps) presents two adjacent oppositely oriented genes (eps1 and eps2), encodes regulatory components, glycosyltransferases and export functions (Fanning et al, 2012b). According to previous studies, B. breve UCC2003 EPS, metabolized by members of the infant microbiota, promotes the health status of infants (Pungel et al, 2020) and downregulates apoptotic responses to protect epithelial cells under imposed inflammatory conditions (Hughes et al, 2017), supporting the notion that EPS-mediated immune response is influenced by the physicochemical nature of these polymers.…”

Intestinal ‘Infant-Type’ Bifidobacteria Mediate Immune System Development in the First 1000 Days of Life

“…Recent studies have shown that infant-type bifidobacteria present different cell surface structures, such as exopolysaccharides (EPSs) and pili/fimbriae, allowing bifidobacteria to colonize the infant’s gut, adhere to intestinal cells and participate in the development of the host immune system [ 66 , 67 ]. Consequently, the administration of EPSs from B. breve UCC2003 might serve as a new strategy for promoting infant health [ 68 ]. In addition, EPSs produced by B. longum subsp.…”