Research Update: Q&A with Michiko Oyoshi, Ph.D.

Michiko Oyoshi, Ph.D., is a Scientific Research Associate at Boston Children’s Hospital and an Assistant Professor of Pediatrics at Harvard Medical School. In 2015, she received a five-year FARE Investigator in Food Allergy Award for her work on maternal factors that influence food tolerance. In a new study published in the Journal of Experimental Medicine, her research team found that breastmilk of mothers exposed to egg during pregnancy and breastfeeding protects nursing newborns against egg allergy symptoms. This study in mice reinforces recent guidance that women should not avoid allergenic foods while they are pregnant or breastfeeding. FARE interviewed Dr. Oyoshi about her research in May 2017, prior to publication.


What first attracted you to food allergy research?

As a child, I suffered from severe asthma, eczema and allergic rhinitis, starting when I was three years old. Later I realized that my childhood allergies fit the theory called “atopic march,” in which a child with one allergy often develops additional allergies. I still remember feeling different and isolated from other children because of my allergies. I had to stay away from regular kids’ activities because many of these – even just laughing hard with friends – triggered asthma attacks that often required emergency treatment and hospitalization. I was fortunate that my environmental allergies resolved after desensitization treatment. This was quite rare in Japan at the time. Finding a doctor who offered this treatment and continuing it each week for five or six years was very hard work for my mother.

As I grew older, I became interested in scientific research. I wanted to understand why some children suffer from multiple allergies, including food allergies. Food allergy is a peculiar disease, because most of the time the child is not sick but is in ever-present danger of anaphylaxis. I could not imagine how much food allergies must amplify a parent’s fears. I wanted to understand the disease mechanisms so that we could develop better means of prevention and treatment to combat the rise in food allergies.


What has sustained your interest?

The relationship between maternal factors and allergies in offspring is poorly understood and a subject of myths. A few decades ago, someone told my mother that my allergies came from her side, which made her feel extremely guilty. I didn’t believe there was concrete evidence for that assertion then, and I feel the same way now. My passion for defining how maternal factors affect food tolerance and food allergy in offspring is even greater now that I am the mother of a two-year-old daughter.


What experimental finding has surprised you the most, and why?

There has been controversy as to whether mothers can influence allergies in children by eating allergenic foods during pregnancy and while breastfeeding. Different studies have found that maternal consumption of food allergens leads to increased risk, unchanged risk, or decreased risk of food allergy in babies. Using a mouse model, we found that exposure of mothers to food protects their offspring from allergy to that food. Interestingly, breastfeeding by food-exposed mothers strongly induced tolerance in adopted offspring whose birth mothers were not exposed to that food. We also found that maternal antibodies in breast milk caused this protection. This result fascinated me, because a role in long-lasting protection against food allergy goes beyond the previously known roles of antibodies in breast milk to temporarily protect babies from viruses and bacteria.


How might your research that is supported by a FARE Investigator in Food Allergy Award affect patient care in the future?

We are testing whether maternal antibodies in human breast milk induce tolerance-promoting regulatory T cells and prevent food allergy in humanized mice (mice that are tailored to respond to human antibodies). Our long-term goals are to better understand tolerance mechanisms in offspring and ultimately to develop therapies that use maternal antibodies to prevent and treat food allergy. Also, our studies may show that maternal allergen exposure during pregnancy and lactation has beneficial effects in protecting babies from food allergy. This would support recent decisions to cancel recommendations that pregnant and breastfeeding mothers avoid allergens.


What unresolved question relating to food allergies would you most like to see answered?

The mechanisms that establish food tolerance or disrupt the development of tolerance are not well understood. The recent finding that early food introduction can decrease food allergy risk is consistent with food allergen transfer through breast milk being important, since this may be the infant’s first food exposure. I would like to see how tolerance is established in normal circumstances and whether maternal environmental factors such as microbiome and nutrition can be modulated during pregnancy and lactation to protect offspring from allergies. Also, the identification of key environmental and genetic factors that lead to tolerance breakdown in early life might reveal why food allergy has become more prevalent in recent years.


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