Objective: Milk oligosaccharides (MOs), first prebiotics for neonates, regulate intestinal microbial composition and may influence long-term health. However, the high structural diversity of MOs among mammalian species, which influences the holobiont development, remains to be explored. This study analyses in vitro functional links between MO structural diversity and metabolic capacities of intestinal commensal bacteria in newborns using pigs and rabbits. Methods: Intestinal commensal bacteria were isolated from digestive contents of suckling piglets and rabbits. The ability of nine strains to consume MOs was analyzed. Isolated bacteria were cultivated with either 2’-Fucosyllactose, 3’-Sialyllactose/6’-Sialyllactose or Lacto-N-Tetraose (Inbiose) as sole energy source, and glucose was used as positive control. Variability in bacterial biomass was assessed spectrophotometrically and short chain fatty acids’ (SCFAs) concentrations were measured by gas chromatography. Results: Our results show strain-specific variations in MO consumption. Bacteroides fragilis, NQMG_s, Bacteroides thetaiotaomicron, Phocaeicola dorei and Phocaeicola vulgatus were efficient at consuming MOs. Their growth and SCFAs production varied according to the type of MO. B.fragilis, B.thetaiotaomicron and P.dorei showed a slight preference for 2’-FL, while 3’/6’-Sialyllactose induced moderate growth of P.vulgatus and NQMG_s. These five strains produced more acetate and propionate with MOs than with glucose. Conversely, Hungatella hathewayi, Bacteroides uniformis, Lactobacillus amylovorous and Limosilactobacillus mucosae were unable to grow with MOs regardless of the structure. Conclusions: This work suggests that the ability of bacteria to metabolize MOs depends on the structure of the MOs. Whole genome sequencing will be carried out to further identify genes involved in the utilization of MOs.