Leena Hilakivi-Clarke, PhD, Professor of Food Science and Nutrition at The Hormel Institute, University of Minnesota, has received a four-year, $1.7M grant from the National Institutes of Health, National Cancer Institute.
The grant will support Dr. Hilakivi- Clarke’s research on how maternal obesity may impact breast cancer risk among daughters—and more specifically, whether gut microbiota may be an influencing factor.
In the United States, over 30% of White mothers and over 50% of Black mothers are overweight or obese during pregnancy. While a woman who is obese can have a healthy pregnancy, obesity during pregnancy increases the mother’s and her child’s later risk of having health problems, including developing Type 2 diabetes, and cardiovascular and neurological diseases.
Obesity is also linked to gut dysbiosis, which is an imbalance of helpful and harmful bacteria in the gut. Humans have evolved to benefit from having certain microbes present in the body. The gut microbiome is essential for supporting the health and proper functioning of multiple organs and systems throughout the body, including the immune system.
Dr. Hilakivi-Clarke’s research will investigate how gut dysbiosis in the offspring of mothers with obesity and their breast cancer risk may be linked, as well as whether such a risk could be reversed by way of certain dietary elements.
While environmental factors will affect the health and diversity of a person’s gut microbiota over time—for better or for worse—the combination of microorganisms initially found in an infant’s body are highly dependent on those found in the mother’s body. These microorganisms are typically introduced to the infant for the first time via the birth canal and breast milk. How maternal obesity during pregnancy can cause gut dysbiosis in the newborn is not known, but it may involve the mother’s gut bacterial metabolites already being altered during pregnancy rather than the mother’s bacteria directly invading the growing fetus.
The development of a person’s microbiome happens in stages. Having the right initial combination of gut microbes early on establishes an environment that allows additional beneficial microbes to colonize the body later, which can help to set up the infant for optimal health over the short and long term. In contrast, lacking key types of microbes may increase an infant’s risk for chronic health problems later on.
Children born to mothers who have obesity can have low levels of certain bacteria that produce short chain fatty acids (SCFAs). SCFAs have many beneficial biological roles, one of which is boosting immune functions. Without sufficient SCFA levels, the body’s immune responses can suffer, which could leave the next generation more susceptible to a number of health risks, including the risk for breast cancer.
If the Hilakivi-Clarke Lab finds a causal link between daughter’s gut dysbiosis and increased breast cancer risk and mortality, the study’s next step will be attempting to reverse both via a diet high in microbiota accessible carbohydrates (MACs) which increase SCFA production.