The recent emergence and spread of anti-microbial resistance (AMR) generates serious concerns. AMR related infections result in 25K deaths and €1.5 billion healthcare costs in the EU annually. A promising strategy involves strengthening the intestinal barrier and modulating gut microbiota using prebiotics. Cell walls polysaccharides, mainly from S. cerevisiae, showed great potential for mitigating antibiotic burden. At present, however, our understanding of the mechanism of action underlying these biological effects is significantly lacking, mostly due rudimentary characterization, which hinders identification of key molecules and delays production of effective feed supplements. A key reason for incomplete characterization is the heterogeneous nature of polysaccharides, which have challenged researchers for years. Recent technological breakthroughs now provide analytical toolsets that enable a more comprehensive understanding of the fine structure of large polysaccharides. The overall objective of the project was to use the Glycomics techniques to characterize in-depth the structure of polysaccharides, specifically mannan and glucan due to their reported bioactivities, present in different non-saccharomyces yeasts, to evaluate and compare their potential anti-adherent and gut microbiota modulator functions, and to unravel their structure-function relation to mitigate the use of antimicrobials in humans and livestock production.
According to the preliminary results obtained, we have identified that the cell-walls from the nine yeast species included in the study contain different ratio and structure of monosaccharides, which could play a beneficial role when compared to cell-walls from S. cerevisiae that only contains glucose and mannose units. Also, since there is a high amount of commercial yeast cell-walls product, mainly for livestock, and with poor structural characterization, this study also included the analysis of these products from supplier based on the USA and in the European Union, and we have concluded that some of the products have important difference among batches, and the purity claimed on the label is not always reliable.
