In vitro measurement of the impact of human milk oligosaccharides on the faecal microbiota of weaned formula-fed infants compared to a mixture of prebiotic fructooligosaccharides and galactooligosaccharides

Aims:  To investigate the impact of human milk oligosaccharides (HMOs) from a single donor (SO), HMOs from multiple donors (PO), a fructooligosaccharides and galactooligosaccharides mixture (FG) on the composition of a batch culture inoculated with faecal microbiota from formula-fed infants. Methods and Results:  Three substrates were compared using 24-h pH-controlled anaerobic batch cultures inoculated with infant faecal slurries. Changes in bacterial populations, short-chain fatty acids (SCFA) production and bacterial 16S rRNA gene profiles were determined. All three substrates significantly increased numbers of bifidobacteria, bacteroides and those aligning with the clostridial cluster XIVa. Neither the FG nor the HMOs substrates supported the growth of the Clostridium perfringens–histolyticum group. SCFA production corresponded to changes observed in bacterial populations. Denaturing gradient gel electrophoresis fingerprint analysis showed a distinct profile of faecal bacteria present in each infant. Conclusions:  HMOs modulated infant faecal culture composition in a similar manner to the prebiotic mixture FG in vitro. Significance and Impact of the Study:  This is the first demonstration of the impact of pure HMOs on the mixed culture of infant faecal bacteria. HMOs induced the growth of several saccharolytic bacterial groups and may thus play a role in the health-promoting attributes of human breast milk and have an extended significance in infant diet during/after weaning.