The current estimated prevalence of Immunoglobulin E-mediated childhood food allergy is ~8%
with up to 11% of caregivers reporting food allergy symptoms. Research also suggests that 40%
of children with food allergy report food allergy to multiple food allergens. Infant food
allergy can result in multiple physical symptoms including colic, vomiting, reflux, bloody
stool, failure to thrive, and eczema, and has been associated with a decreased quality of
life in infants and their caregivers. Treatment options for infant food allergies are
currently limited. In most situations, mothers must choose between continuing to breastfeed
while attempting to avoid potential food allergens or ending breastfeeding and providing
expensive hydrolyzed infant formula.
Breastfeeding affects mortality in children under the age of 5 years old reducing episodes of
diarrhea and respiratory infections, and decreasing hospital admissions by up to 70%. The
Lancet series on breastfeeding quantified the global economic health impact of breastfeeding
on healthcare due to infant illness and mortality. Of the estimated 130 million live births
per year globally, 820,000 infant deaths, 87% of which are under 6 months old, could be
mitigated with improved breastfeeding practices. The Lancet report projects that a 10%
increase in exclusive breastfeeding up to 6 months would translate to an estimated $312
million in healthcare savings in the US alone. Long-term (up to 2 years), additional
breastfeeding benefits would impact treatment costs for infants and toddlers as much as $2.45
billion in the US.
Many breastfeeding women are led to believe that they should not eat certain foods (e.g.,
dairy) because this might lead to food intolerance in their infants. Without a method to
directly test human milk, mothers will methodically cut out whole food groups (most of them
extremely healthy) without realizing that the true problem is going undetected. This often
starts with dairy and quickly spirals until her diet is very limited. A total elimination
diet is typical for this community. Many women reduce their intake down to as few as five
foods (i.e., chicken, mango, coconut oil, spinach, and potato). This extreme dietary
restriction puts mothers and infants at risk for nutritional deficiencies with potential
life-long effects.
Currently, there is no mechanism available for mothers to know what allergens are present in
their milk. Food diaries are inadequate as dietary protein only enters breastmilk a portion
of the time and is present in the milk for a variable amount of time depending on several
factors including metabolism, nursing schedule and unknown individual characteristics. A
simple at-home test strip would empower women to continue breastfeeding by removing the
mystery of the allergens present. Mothers and pediatricians could use this information to
determine what is causing reactions and then follow up to determine if informed dietary
elimination made mom's milk safe. Women could then enjoy their favorite foods and be
confident in feeding their infant.
Free to Feed has developed a first-in-class solution using patent-pending technology to
detect food allergen proteins in human milk. With this knowledge, mothers would be able to
identify the culprit and remove the food from their diets or wait for the allergen to clear
from their milk prior to feeding through repeated testing. This technology hopes to empower
mothers to breastfeed longer, giving both mom and baby lifelong benefits, while relieving the
stress of inducing unknown effects.
Previous research has identified the presence of specific nonhuman proteins found in human
milk. While an abundance of information exists on bovine proteins in human milk, very limited
research exists examining the presence of soy proteins in human milk. Furthermore, there is
no notable existing research validating the use of strips or other tools to detect food
allergens in human milk.
The first aim of this research is to validate the use of this patent-pending technology,
Freedom Strips, to detect bovine and soy-based food allergen proteins in human milk with the
goal that women will be able to test their milk for common antigens (e.g., dairy) and make
informed decisions as to whether the milk should be fed to their infants. This will benefit
mothers and babies on a global scale as it will enable women to quickly and easily determine
if their milk is safe to feed their infants.
One hypothesis explaining the discomfort and increasingly distressed behavior of infants when
consuming human milk containing food allergens relates to potential changes in the
gastrointestinal microbiome. There is limited information on the relationship between
maternal cow's milk and soy consumption and the gastrointestinal microbiome of mothers and
their offspring. Therefore, the second aim of this study is to explore the impact of maternal
cow's milk and soy consumption on breastmilk and maternal/infant gastrointestinal
microbiomes.
Furthermore, elimination diets, dietary challenges and food reintroduction can put a
significant amount of stress on mothers of children with infant food allergies. More research
is needed examining how maternal stress levels might change throughout this process. A third
aim of this study is to examine and compare maternal stress levels during dietary elimination
and food challenge periods.
The proposed research study will build upon previous literature by increasing our knowledge
related to the detection and identification of nonhuman proteins, specifically bovine and
soy, in human milk. This study is unique because it will include a dietary intervention with
increasing doses of soy or bovine milk examining how the amount of intake of a food allergen
may impact protein detection. It also unique because it includes the investigation of
maternal stress and maternal/infant GI microbiomes, both of which may provide more insight on
the mechanisms and outcomes of infant food allergies. While our research lab has experience
in investigating a variety of factors related to human milk and the microbiome, this study is
unique from all other studies currently being done at the University of Idaho.
This study will consist of a randomized, cross-over, dietary intervention research design
comprising a 5-day run-in period, two 3-day dietary interventions with a 7-day washout period
between them, and a final 2-day washout period after the 2nd intervention. 40
mother-offspring dyads will be recruited to participate. Participants will be randomly
assigned to order of intervention. Demographic and health data will be collected at baseline
(d0) as will information related to typical infant crying patterns and maternal stress
(Perceived Stress Scale). Baseline data collection will also include collection of a human
milk sample (approximately 10 mL), a maternal stool sample, and an infant stool sample.
Participants will complete two 24-hour dietary recalls during baseline collection (day 0)
rather than one to obtain typical dairy and soy intake.
Run-in elimination period: After baseline collection, both groups will undergo a 5-day run-in
period during which time half the subjects will eliminate soy and the other half will
eliminate cow's milk. Participants will be provided with a list of foods and ingredients to
avoid during this time facilitated by a registered dietitian. During these 5 days,
participants will complete a daily compliance check and indicate any soy or bovine
products/foods that they may or may not have consumed. On d5 of this run-in period,
participants will again provide samples of milk and maternal and infant stool and will
complete the Perceived Stress Scale.
Dietary intervention period I: After completing the run-in period, the women will consume 200
mL, 300 mL, and 400 mL of bovine milk or soy milk during d1, d2, and d3 (respectively).
During each dietary intervention period, participants will provide 3 samples of milk
(approximately 10 mL each) each of the 3 days (12 samples total), 1 maternal stool sample,
and 1 infant stool sample. Daily logs will be kept to ascertain dairy and soy intake
compliance, infant crying and fussiness, and maternal/infant stooling patterns. On the third
day of the dietary intervention, mothers will again complete the Perceived Stress Scale.
Washout period I: The first dietary intervention period will be followed by a 7-day washout
period during which time the product that was not eliminated the first time will be
eliminated from the diet. On the last day of this washout period, participants will provide
an optional maternal and/or infant stool sample; they will also complete the Perceived Stress
Scale. Infant crying and fussiness will also be monitored and recorded daily during the first
two days of the washout period.
Dietary intervention period II: After this, each subject will consume 200 mL, 300 mL, and 400
mL of bovine milk or soy milk (which ever they did not consumer in the first intervention
period) during d1, d2, and d3 (respectively). Data and samples collected during intervention
I will be collected during intervention
- II.
Washout period II: The second dietary intervention period will be followed by a 2-day washout
period during which time they will continue to eliminate the food produce eliminated in
intervention period II.
On the last day of this washout period, subjects will provide a milk
sample (approximately 10 mL), a maternal stool sample, and an infant stool sample. Infant
crying and fussiness will also be monitored and recorded daily.
