Baby’s first poo helps predict immune health and risk of allergy

The study, published in Cell Reports Medicine​, suggests that the development of a healthy immune system and microbiota may actually start well before a child is born, and signals that the tiny molecules an infant is exposed to in the womb play a fundamental role in future health.

“Our analysis revealed that newborns who developed allergic sensitization by one year of age had significantly less ‘rich’ meconium at birth, compared to those who didn’t develop allergic sensitization,”​ says the study’s senior co-author Dr. Brett Finlay, a professor at the Michael Smith Laboratories and departments of biochemistry and molecular biology, and microbiology and immunology at University of British Columbia (UBC).

Meconium, which is typically passed within the first day of life, is made up of a variety of materials ingested and excreted during development, ranging from skin cells, amniotic fluid and various molecules known as metabolites.

The study’s lead author Dr. Charisse Petersen, a research associate in UBC’s department of pediatrics, explains: “Meconium is like a time capsule, revealing what the infant was exposed to before it was born. It contains all sorts of molecules encountered and accumulated from the mother while in the womb, and it then becomes the initial food source for the earliest gut microbes.”

For their study, the researchers analysed meconium samples from 100 infants enrolled in the CHILD Cohort Study (CHILD)​, a world-leading birth cohort study in maternal, newborn and child health research.