Shaping health beyond nutrition
Koch showed that maternal antibodies in breast milk are important factors that help ensure proper infant growth. She found that mice born to mothers that can’t produce antibodies grow more slowly than mice born to mothers who pass antibodies to their pups during nursing.
These findings echo epidemiological research in people which suggests that breastfeeding may have lifelong health effects. Studies have linked breastfeeding to a range of effects, from a subtle bump in IQ to reduced cholesterol in adults.
“The field has understood that these associations exist, but it's been very unclear what's driving these long-term impacts on health,” Koch said.
Her goal is to reveal the factors in breast milk that shape infant health both short term and long term, and understand how they do it. Such findings could help improve formula such that it provides similar benefits. Her own work suggests that breast milk’s importance extends beyond nutrition and that antibodies could be a key component of its health-promoting effects.
Setting the stage for long-term health
Koch works at the interface of the maternal immune system, the infant immune system and the developing infant microbiome. Scientists continue to reveal more about the health-promoting effects of the right microbial mix, which ensures proper nutrient absorption and influences both physical and mental health.
At the same time that infants begin ingesting breast milk, their intestinal tracts are being colonized by a rush of bacteria. Their nascent immune systems are also learning friend from foe, starting with the new microbes.
“Maternal antibodies are mediating the first host-microbiota interactions and helping to set the stage in the intestine,” she explained.
In this role, maternal antibodies may help determine which species of bacteria colonize the infant intestinal tract as well as “teach” the infant’s immune cells how to respond properly to the bacteria they’re encountering. Her previous work suggested that maternal antibodies help keep infant immune cells from overreacting to gut bacteria. As a Pew Scholar, she plans to use mice to study how maternal antibodies influence the complex ecosystem inside the gut and whether their effects on infant growth are mediated through specific microbial species.
Koch will also explore how maternal antibodies help shape infant immune responses and whether this has metabolic consequences that can influence growth. Though her initial studies focus on infancy, her goal is to understand how these interactions can influence health throughout life.
“I want to build a comprehensive view of health that we can apply to other questions that don't necessarily have to do with maternal antibodies but could have to do with other early life events,” Koch said. “The more we understand about the basic biology of how health is set up early in life, the more we could do to proactively promote practices or develop therapies.”