Impact of purified human milk oligosaccharides as a sole carbon source on the growth of lactobacilli in in vitro model

Recently, there is a growing interest in the use of oligosaccharides as prebiotics in order to modulate the growth of beneficial gut microbiota. It is known that human milk is a rich source of complex oligosaccharides. This paper reports the in vitro growth of six strains of lactobacilli in media containing purified human milk oligosaccharides (HMOs) obtained from breast milk. Based on the evaluation of bacterial densities in the growth media, together with the evaluation of pH values and bacterial metabolite detection, we concluded that the lactobacilli tested did not appear to be active HMO consumers. In the case of four strains (Lbc. fermentum, Lbc. animalis and two strains of Lbc. delbrueckii subsp. bulgaricus), no increase in bacterial density was detected. Two strains (Lbc. acidophilus and Lbc. casei subsp. paracasei) showed a slight, but insignificant increase in bacterial densities during 24 h of incubation.