Breastfeeding shapes infant microbiome, reducing asthma risk and supporting immunity.
Conducted by NYU Langone Health and the University of Manitoba, a recent study focused on the significance of the role of human breast milk in shaping a baby’s microbiome (gut health) and supporting respiratory development during infancy. Researchers specifically examined the impact of breastfeeding beyond three months and discovered that breast milk appears to play a unique role in regulating the microbial mix within an infant’s gut and nasal cavity, providing protection against respiratory conditions, including asthma.
The team explained that breastfeeding beyond three months allows the gradual development of a healthy microbiome in infants, specifically in the digestive system and the upper part of the respiratory tract. When breastfeeding is stopped early, this natural progression is disrupted, potentially leading to a greater risk of developing asthma during preschool years. One key component in human breast milk, known as human milk oligosaccharides, requires the presence of certain microbes for proper digestion. These sugars are broken down by specific bacteria that are encouraged to grow only through breastfeeding.
On the other hand, infants who are weaned early and switch exclusively to formula feeding host a different set of microbes that aid in formula digestion. While formula-feeding microbes are common in all babies eventually, their early arrival has been linked to a higher asthma risk. This highlights the essential role of breastfeeding in pacing microbial colonization.
The lead researchers, including Liat Shenhav, PhD, emphasized that the right microbes need to arrive in a specific sequence at the correct time, much like a pacemaker regulates heart rhythm, to ensure a healthy microbiome development. Shenhav, along with Meghan Azad, PhD, collaborated to demonstrate how breastfeeding’s structured pace of microbial colonization contributes to respiratory health.
Another important discovery was the presence of the bacterium Ruminococcus gnavus in the gut microbiomes of infants weaned earlier from breast milk. This bacterium appeared sooner in formula-fed infants and is associated with the production of short-chain fatty acids and tryptophan metabolism. Previous studies have connected tryptophan and its metabolites with immune system regulation, and disruptions in this process have been linked to a higher risk of asthma. The study concluded that an infant’s microbiome is not only vital for digestion but also plays a critical role in immune system development, further linking breastfeeding duration to long-term respiratory health outcomes.
The study was published in Cell and followed the microbial development in infants’ guts and nasal cavities over their first year. Data from the CHILD Cohort Study, a long-term Canadian research initiative tracking 3,500 children from birth into their teenaged years, provided insight into how breastfeeding duration affects microbiome development. Even after accounting for factors like prenatal exposure to smoke, antibiotics, and maternal asthma history, breastfeeding duration emerged as a major determinant of a child’s microbiome and its impact on respiratory health.
The researchers believe their findings may lead to more targeted prevention strategies for asthma in cases where breastfeeding is not possible for the recommended duration of at least three months. Future research in this area could pave the way for innovative approaches to respiratory health in infants, particularly those unable to benefit from extended breastfeeding. Spreading awareness of its benefits and educating mothers on the link between feeding and future health can help ensure more infants are protected.
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Study reveals impact of human breast milk on infant microbiome and respiratory health
