Your Gut Feeling About Babies in Nature Is Right

Getting a formula-fed baby out into green spaces can improve their gut microbiome and guard against obesity, asthma and allergies.


For new parents, breastfeeding can feel like the holy grail — a mythical treasure with miraculous powers. But of course, not every infant can be fed this way.

Ultimately “fed is best” when it comes to infant nutrition, but breastfeeding still seems to provide certain benefits. These benefits, such as a reduction in obesity, allergies and asthma, are thought to be linked to gut bacteria. Now, research suggests that spending time in nature can shift a formula-fed baby’s gut microbiota towards that of breastfed peers.

The study looked at fecal samples from 355 four-month-old infants as part of the Canadian Healthy Infant Longitudinal Development (CHILD) study. The Edmonton-based samples were then mapped by postal code and proximity to natural environments including forests, grasslands, lakes and rivers.

Normally, a formula-fed infant will have a greater variety of gut bacteria than their breastfed counterparts. However, living within 500 metres of a natural environment appears to mitigate this, reducing the overall variety of gut bacteria to levels more often seen in breastfed babies.

Unfortunately for city dwellers these results only apply to ‘natural’ rather than ‘man-made’ green spaces, so a playground doesn’t count. However, owning a pet also seems to play a key role.

It seems counterintuitive; surely being in nature or welcoming a drooling pup into your home would increase bacteria levels, wouldn’t it? Well, yes, but it’s the types of bacteria that are important here. The researchers believe that exposure to a wild environments encourages the growth of specific bacteria, types that are associated with a healthy gut. As these grow, other bacteria are crowded out, leaving a gut microbiome that is more similar to what is seen in breast-fed infants.

In terms of pets, senior author Anita Kozyrskyj believes it’s a dog effect. “Even if you live in a highrise, if you have a dog you go out and use the natural spaces near your home. It’s likely that the pet is the conduit.”

In fact, the association between natural vegetation and bacterial diversity was only seen in formula-fed infants in homes with pets.

“This is one of the first pieces of evidence for a nature-related intervention that could possibly help promote healthy gut microbial composition in infants who are not breastfed,” explains Kozyrskyj, who is a pediatrics professor at the University of Alberta and the principal investigator for SyMBIOTA, a research team that studies how changes in infant gut microbiota can lead to the development of obesity, allergies and asthma in children.

From here, the team plans to follow the formula-fed infants and and track the impact on their health. While we wait to see the long-term impacts of access to wild spaces, this research is a poignant reminder that nature is good for our health.

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Amy Noise is a science communicator who is fascinated by how and why the world works. Always learning, she is passionate about science and sharing it with the world to improve and protect our health, society and environment. Amy earned her BSc (biology and science communication) at the University of Manchester, and MSc (nutrition science and policy) at King’s College London, UK. She tweets sporadically @any_noise