Impact of GOS and 2'-FL on the production and structural composition of membrane-associated exopolysaccharides by<i> B.</i><i> adolescentis</i> and<i> B.</i><i> infantis</i>

Bifidobacteria, which are increasingly linked to health benefits to the host, produce structurally complex exopolysaccharides which are considered to be effector molecules responsible for health effects. It is currently not clear how the bacterial growth conditions, and especially the carbon source, affect the structural composition of the EPS. Here we present our investigations into the impact of the addition of 2 '-fucosyllactose '-fucosyllactose (2'-FL) and galactooligosaccharides (GOS), which are non-digestible carbohydrates added to infant formula, as the sole carbon source during the growth of B. adolescentis and B. infantis. . Intriguingly, B. adolescentis produced EPS with larger molecular weights in the presence of GOS or a mixture of GOS/2'-FL. B. infantis showed increased growth levels in the presence of 2'-FL, and also produced an alpha-1,4-glucan polymer, whose amount was increased when grown on GOS. These findings highlight the species-specific effects of growth conditions on EPS structures.