Immune Modulation Capability of Exopolysaccharides Synthesised by Lactic Acid Bacteria and Bifidobacteria (original) (raw)

During recent years the exopolysaccharides (EPS) produced by some strains of lactic acid 20 bacteria and bifidobacteria have attracted the attention of researchers, mainly due to their potential 21 technological applications. However, more recently it has been observed that some of these EPS 22 present immunomodulatory properties, which suggest a potential effect on human health. Whereas 23 EPS from lactic acid bacteria have been studied in some detail, those of bifidobacteria largely 24 remain uncharacterized in spite of the ubiquity of EPS genes in Bifidobacterium genomes. In this 25 review we have analysed the data collected in literature about the potential immune modulating 26 capability of EPS produced by lactic acid bacteria and bifidobacteria. From this data analysis, as 27 well as from results obtained in our group, a hypothesis relating the physico-chemical 28 characteristics of EPS with their immune modulation capability was highlighted. We propose that 29 EPS having negative charge and/or small size (molecular weight) are able to act as mild stimulators 30 of immune cells, whereas those polymers non-charged and with a large size present a suppressive 31 profile.