Changing a baby’s first diaper can provide clues about your child’s risk of developing allergies.

Although it seems like an unusual place to look for answers, a team of Canadian scientists has shown that the composition of a baby’s first bowel movement is linked to allergies in their first year of life.

A thick, dark green substance known as meconium is at the heart of the study. The substance is composed of materials that were ingested during development. It is usually passed within the first day after birth.

Scientists analyzed meconium samples from 100 infants enrolled in a worldwide birth study focused on newborn health research.

They learned that the fewer molecules the meconium contained, the greater the child’s risk of developing allergies within a year. The researchers further discovered that a fewer number of certain molecules was associated with changes in bacterial groups. Bacterial groups are key players in gut microbe diversity, which is important for disease prevention and good health.

Using a type of artificial intelligence, the team combined babies’ meconium information and other data. That allowed them to accurately predict whether an infant is at risk of developing allergies.

Children who have allergies face a higher risk of developing asthma. The study presents a chance to identify at-risk infants who could benefit from early help before they begin to show signs of allergies or asthma.

The findings may one day bring new purpose to a mundane task: Changing an infant’s first diaper could also help change their future.