CAMBRIDGE, Mass. — Certain gut bacteria may process nutrients found in breast milk and infant formula in ways that help train the immune system and protect against harmful reactions, according to a study published in Nature.
The research, led by Noah Palm, Ph.D., a Food Allergy Science Initiative Principal Investigator and Professor of Immunobiology at Yale School of Medicine, examined how Bifidobacterium interacts with dietary nutrients during early life.
Researchers found that the bacteria can convert a nutrient from breast milk or supplemented infant formula into acetylcholine, a neurotransmitter involved in several biological processes.
The acetylcholine produced by the bacteria strengthened the intestinal immune system by increasing production of immunoglobulin A, or IgA, a protective antibody. Higher IgA production improved immune resistance to salmonella infections in the study.
The findings could help researchers better understand why some children develop serious food allergies while others remain allergy-free.
Microbiome research can be difficult because of the large and complex communities of bacteria living in the digestive system. To identify the role of individual strains, Palm and his team used new screening tools to examine how specific bacteria behave, what substances they produce and how they interact with the body.
The researchers tested more than 100 bacterial strains and identified the bacteria and enzymes responsible for transforming an essential dietary nutrient associated with gut and brain health.
“This could change how the microbiome is studied going forward,” said Carlos Bosques, M.D., Chief Executive Officer of the Food Allergy Science Initiative. “Dr. Palm’s research uncovers specific bacteria settled in the gut that help shape how the immune system learns to respond to the food they eat, including whether it becomes more tolerant or more reactive. This kind of innovative discovery is exactly what FASI exists to support. It pinpoints a target, either the bacteria or their enzymes, that can be used to promote gut and brain health.”
Palm cautioned that the work remains at an early stage but said it adds to researchers’ understanding of how diet, gut bacteria and the immune system interact.
“This work, while still in its early stages, reveals an additional layer of cooperation between the microbiome and the immune system,” Palm said. “Our team is excited to add to a growing understanding of how the relationship between diet, gut bacteria, and the immune system may support the body’s natural defenses.”
Since 2016, the Food Allergy Science Initiative has provided more than $50 million to support food allergy research at institutions including Yale.
The study, titled “Commensal-derived acetylcholine enhances mucosal immune education,” appears in the July 23 print edition of Nature.
