Effects of Different Human Milk Oligosaccharides on Growth of in Monoculture and Co-culture With

Human milk oligosaccharides (hMOs) are important bioactive components in mother's milk contributing to infant health by supporting colonization and growth of gut microbes. In particular, genus is considered to be supported by hMOs. Approximately 200 different hMOs have been discovered and characterized, but only a few abundant hMOs can be produced in sufficient amounts to be applied in infant formula. These hMOs are usually supplied in infant formula as single molecule, and it is unknown which and how individual hMOs support growth of individual gut bacteria. To investigate how individual hMOs influence growth of several relevant intestinal bacteria species, we studied the effects of three hMOs (2'-fucosyllactose, 3-fucosyllactose, and 6'-sialyllactose) and an hMO acid hydrolysate (lacto-N-triose) on three and one and introduced a co-culture system of two bacterial strains to study possible cross-feeding in presence and absence of hMOs. We observed that in monoculture, subsp. could grow well on all hMOs but in a structure-dependent way. reached a lower cell density on the hMOs in stationary phase compared to glucose, while subsp. and were not able to grow on the tested hMOs. In a co-culture of subsp. with , different effects were observed with the different hMOs; 6'-sialyllactose, rather than 2'-fucosyllactose, 3-fucosyllactose, and lacto-N-triose, was able to promote the growth of subsp. . Our observations demonstrate that effects of hMOs on the tested gut microbiota are hMO-specific and provide new means to support growth of these specific beneficial microorganisms in the intestine.