Food Molecules Pass From Mom to Baby: One Cause of Infant Colic and Infant Allergy

Nursing mothers often ask if the food they eat might be triggering their baby’s fussiness, digestive discomfort, and allergies. The answer is a cautious yes, quite possibly.

We know that during pregnancy, large molecules from food can pass from a mother’s intestine into her bloodstream and reach the baby in the womb. ⁽⁸⁾

These molecules do not belong in the womb. Naturally, they trigger a defensive immune reaction in the baby, pre-conditioning the baby to launch another immune reaction when they encounter these same food molecules in their mother’s milk. ⁽⁹⁾ 

Please note: whole food molecules are not supposed to be present in the bloodstream or in the womb. They are supposed to be broken into their smallest components while in the intestine – into amino acids, fatty acids, minerals, and vitamins—before being allowed into the body.

When food molecules leak into the bloodstream, it is a sign that the intestinal lining is damaged, and is perforated with tiny holes that allow these larger molecules to pass through. ⁽¹⁰⁾

A permeable intestine, also called “leaky gut,” is sadly not rare. Many of us have a permeable intestine to some extent because of the foods we eat, the medications we take and the toxins we are exposed to. This means that many of our babies are exposed to food molecules while in the womb.

Researchers believe that prenatal exposure to food molecules may be a major cause of infant colic and allergy. ⁽¹¹⁾ They believe that this exposure conditions unborn babies to respond with inflammation when they encounter these same food molecules later on in their mother’s milk. This is particularly the case if there is a history of allergy or autoimmune disease in the family.

A study from 2016 affirms this association. Researchers looked at the amniotic fluid from several mothers mid-pregnancy and were able to identify ten major food allergens in the fluid, including from cow’s milk, fruit, egg, fish, nuts, and wheat. ⁽¹⁾ This means that these babies were being preconditioned to respond with inflammation to these foods—and indeed, that colicky babies are in a state of mild “systemic inflammation.” ⁽⁷⁾ 

Inflammation can show up in different ways in a baby. It can show up as insomnia, wheezing, rashes, eczema, fussiness, restlessness and unhappiness, and also infant colic—the severe digestive pain that repeats nearly every day in about 20% of babies, starting at 2-3 weeks after childbirth and resolving at between 3-4 months of age. ⁽¹²⁾

Decades ago, infant colic was a medical mystery. Even today, many pediatricians, MDs, and pediatric nurses are not up-to-date on the research and do not know the causes or best treatments for infant colic. Because it is fairly common, infant colic has been normalized. Instead of receiving useful information, parents are often patted on the back and assured that colic is normal and will pass.

Another area of research has looked into the intestinal flora of colicky and non-colicky infants. It turns out that the intestinal flora of colicky babies is colonized by fewer strains of helpful bacteria and yeasts compared to the flora of non-colicky infants. The depleted flora of colicky babies makes their intestine more permeable and more prone to inflammation. ⁽¹³⁾

Research shows that the quality of the intestinal flora is better in babies who have been born vaginally ⁽¹⁴⁾ and who are breastfed and that these babies have less infant colic. However, not all vaginally born and breastfed babies are free of infant colic—far from it.

In any case, a 2020 study examined the very first stool of meconium after childbirth of babies who went on to develop infant colic and those who did not, and found that the difference already exists at this time. ⁽²⁾ 

Other research has noted connections between the mother’s diet during pregnancy as well as her long-term health history and her baby’s tendency to develop allergies and develop other health problems. ⁽²⁾⁽³⁾ Researchers are actively looking into ways to improve the mother’s diet and intestinal health, so as to bring improvement to both the mother and her prospective children. ⁽⁵⁾

This is doubly important because research now also documents that infant colic—once considered normal and harmless—is predictive of digestive problems, allergy, and even learning and neurological problems later in life. ⁽⁶⁾

I personally take infant colic very seriously, having gone through it with my first-born and wishing I had known then what I know now. In my book, Mother Food, I describe many of these entangled factors and suggest ways to unwind them and improve everyone’s health and wellbeing. I believe it is possible to prevent or to improve the symptoms of infant colic in almost all cases and that this should be a top priority for new parents and their healthcare providers.

This post began by answering the question: does the food that a mother eats somehow get into her milk and trigger her baby’s colic? The short answer is yes. The long answer has to do with the mother’s permeable intestinal lining, with a baby’s depleted flora, and with other factors that influence the baby’s proclivity to develop allergies. Indeed, many areas of research today are describing links between a mother’s health and her baby’s tendencies toward health or disease.

The good news is that parents can improve their own and their baby’s intestinal flora and resilience to inflammation, and that the long-term benefits for the entire family are significant.

Try our Organic Baby and Probiotic Toddler Drops to support your baby’s digestive health! 

1. Pastor‐Vargas, C, Maroto, AS, Díaz‐Perales, A, Villalba, M, Esteban, V, Ruiz‐Ramos, M, de Alba, MR, Vivanco, F, Cuesta‐Herranz, J. Detection of major food allergens in amniotic fluid: initial allergenic encounter during pregnancy. Pediatr Allergy Immunol 2016: 27: 716– 720.

2. Korpela, K., Renko, M., Paalanne, N. et al. Microbiome of the first stool after birth and infantile colic. Pediatr Res 88, 776–783 (2020). https://doi.org/10.1038/s41390-020-0804-y

3. Kim et al., Maternal Perinatal Dietary Patterns Affect Food Allergy Development in Susceptible Infants. The Journal of Allergy and Clinical Immunology: In Practice 7:2337-2347.e7 (2019) 10.1016/j.jaip.2019.03.026

4. Rhoads et al., Infant Colic Represents Gut Inflammation and Dysbiosis, The Journal of Pediatrics, 2018: 203: 55-61.e3. https://doi.org/10.1016/j.jpeds.2018.07.042 .

5. 1.Hurd L. Optimizing the Microbiome and Immune System With Maternal Diet in Pregnancy and Lactation May Prevent Food Allergies in Infants. ICAN: Infant, Child, & Adolescent Nutrition. 2015;7(4):212-216. doi:10.1177/1941406415595861

6. Savino, F., Castagno, E., Bretto, R., Brondello, C., Palumeri, E. and Oggero, R. (2005), A prospective 10‐year study on children who had severe infantile colic. Acta Pædiatrica, 94: 129-132. doi:10.1111/j.1651-2227.2005.tb02169.x

7. Pärtty, Anna∗; Kalliomäki, Marko∗; Salminen, Seppo†; Isolauri, Erika∗ Infantile Colic Is Associated With Low-grade Systemic Inflammation, Journal of Pediatric Gastroenterology and Nutrition: May 2017 – Volume 64 – Issue 5 – p 691-695 doi: 10.1097/MPG.0000000000001340

8. Maternal–Fetal Nutrient Transport in Pregnancy Pathologies: The Role of the Placenta

9. Maternal Microbiota, Early Life Colonization and Breast Milk Drive Immune Development in the Newborn

10. The Leaky Gut: Mechanisms, Measurement and Clinical Implications in Humans

11. Influences of Maternal Factors Over Offspring Allergies and the Application for Food Allergy

12. Colic

13. The Gastrointestinal Microbiome in Infant Colic: A Scoping Review

14. The Effects of Delivery Mode on the Gut Microbiota and Health: State of Art

Hilary’s book, Mother Food , is a must-read if you want to learn more about lactogenic foods to support your milk supply, food sensitivities in mom and baby, and curbing sugar cravings.