New parents wondering whether their infants will develop allergies within their first year of life may find the answer in their baby’s first poop, suggest new findings published in the journal Cell Reports Medicine by University of British Columbia (UBC) scientists.

Meconium, a thick, dark green substance in a newborn’s poop, is typically passed within a baby’s first day of life. The goo is a mash-up of different materials ingested and excreted while babies are in the womb, including skin cells, amniotic fluid and metabolites.

For the study, UBC researchers checked meconium samples from 100 newborns enrolled in the CHILD Cohort Study. Scientists evaluated a mix of meconium, microbe and clinical data with a machine-learning algorithm that yielded a highly accurate (76%) prediction showing whether an infant would develop allergies by the age of 1.

Findings revealed that newborns with fewer different types of molecules in their meconium were more likely to experience allergies. What’s more, researchers noted fewer amounts of certain molecules linked with key bacterial group alterations that affect the proliferation of gut microbes—called the microbiota—that influence health and disease.

“This work shows 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,” said Charisse Peterson, PhD, a research associate in UBC’s Department of Pediatrics and the study’s lead author.

Stuart Turvey, MBBS, a professor at UBC, who is also codirector of the CHILD Cohort Study and one of the coauthors of the inquiry added that these findings can also help to “identify at-risk infants who could benefit from early interventions before they even begin to show signs and symptoms of allergies or asthma later in life.”

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