“Breakthrough” Morinaga Milk study sheds light on bifidobacteria impact on HMOs and infant gut microbiome

26 Jul 2022 --- Research by Morinaga Milk has unveiled the order in which Bifidobacterium species reach an infant’s gut has an impact on the way human milk oligosaccharides (HMOs) are utilized.

“This new study has definitely uncovered a breakthrough in understanding how the beneficial bifidobacterial species are formed and which species can dominate the infant gut microbiome at the early stage of life,” Dr. Chyn Boon Wong, lead research associate at Morinaga Milk Industry, tells NutritionInsight.

“It was surprising to us that the arrival order of the species in the infant gut could be another major force driving the formation of Bifidobacterium communities in breastfed infant gut. It is generally recognized that the ability of bifidobacteria species to utilize HMOs is the main force in selecting and promoting the growth of specific bifidobacterial species for the establishment of infant gut microbiome.”

The study included four representative species of infant-type human-residential bifidobacteria (HRB). These included Bifidobacterium bifidum, B. longum subsp. infantis, B. longum subsp. longum, and B. breve. Measured was HMO-utilization ability, which significantly influenced species dominance and bifidobacterial community structure.

“The results provide insight into previously unexplained B. breve abundance in breastfed infants and highlight the importance and history dependency of initial community assembly and its implications for the maturation trajectory of the infant gut microbiota,” the study notes.

Differences between the four strainsThe arrival time of the probiotics showed HMO-utilization effects.
Published in the ISME Journal, the findings reveal the arrival order of the species in the infant's gut showed a high influence on the infant gut microbiome assembly, and bifidobacterial species utilization on HMO varied.

The study notes that the four different infant-type HRB species showed different abilities in utilizing HMOs. “B.bifidum and B. infantis both have a strong ability to “dominate through inhibitory priority effects in vitro.” 

In comparison, B. longum is described as a “modest competitor” for HMO utilization, and B. breve appears to be the weakest.

“However, B. breve could dominate against stronger competitors (B. bifidum and B. infantis) if presented in the community early, despite its considerable fitness differences in HMO-utilization ability,” the study says.

“B. breve is frequently isolated from infant intestines and is recognized as infant-type HRB. Specific strains of B. breve have also been increasingly incorporated as probiotics agents in infant formula and supplements,” Wong underscores.

Previously, probiotics have shown positive effects for early-born infants which have an immature gut microbiome. 

“Bifidobacterium breve is one of the predominant species present in the infant gut and is widely recognized for its beneficial roles in maintaining infant health. Studies have shown that a specific strain of B. breve shows clinical benefits on stimulation of bifidobacterial colonization, alleviation of allergic disorders, and protecting premature infants against NEC,” says Wong.

Dominating based on arrival
The findings suggest that the bifidobacterial species in infants' gut microbiome can have long lasting effects throughout adulthood when "arriving" soon after birth. 

“The results show that if B. breve was present in the infant gut microbiota at birth, it was more likely to dominate in the community at four months of age. The observed trends in the infant’s gut for B. breve were consistent with the in vitro data in the present study, suggesting that priority effects may have contributed to the dominance of B. breve,” says the company.

B. breve is also the dominant bacteria in breastfed infants’ gut, which may explain its priority effects. Infants that breastfeed have shown to have a stronger immune system, due to more advanced bacteria in the gut.

“B. breve dominated through priority effects, which were partly underpinned by its ability to utilize fucose, an HMO degradant produced by other species. We also analyzed publicly available in vivo fecal metagenome data from a cohort of infants and observed trends consistent with our in vitro findings, particularly for B. breve,” the study notes.

“Together, our study demonstrates the importance of priority effects on establishing bifidobacterium communities.”

By Beatrice Wihlander