Pollution exposure in infancy may impact health and development, study finds


New research suggested that pollution exposure during the first six months of life can alter levels of gut bacteria, potentially leading to increased risk for disease as well as delayed neurodevelopment.

The research was published in the journal, Gut Microbiomes, and led by Tanya Alderete, PhD, assistant professor of Integrative Physiology at University of Colorado at Boulder (CU Boulder). For their study, Alderete and a team of researchers aimed to analyze the impacts of pollution exposure on microbial health during infancy.

According to the study, during the first two or three years of life, various factors including a mother’s milk, solid food, antibiotics, and environmental influences shape a child’s gut microbiome make up. Microbial health, according to researchers, can influence bodily systems such as appetite, insulin sensitivity, immunity, as well as mood and cognition. While many gut bacteria can be beneficial to health, certain microbiome compositions have been linked to chronic illnesses such as Crohn’s disease, asthma and type 2 diabetes, according to the study.

“The microbiome plays a role in nearly every physiological process in the body, and the environment that develops in those first few years of life sticks with you,” said researcher, Maximilian Bailey, MS, a medical student at Stanford University in Stanford, California, who recently obtained his masters in Integrative Physiology at CU Boulder in a statement.

The study involved fecal samples from 103 healthy, primarily bread-fed Latino infants enrolled in the Southern California Mother’s Milk Study. Using data from the United States Environmental Protection Agency’s Air Quality System, researchers obtained hourly data on pollution rates near each infant’s home address. Researchers estimated the infants’ exposure to PM2.5 and PM10, fine particles released from sources such as factories and wildfires, as well as nitrogen dioxide (NO2), a gas emitted mostly from cars, according to researchers. Then, through genetic sequencing, scientists analyzed the infants’ gut-microbial profile.

The study showed that infants with the highest exposure to PM2.5 had 60 percent less Phascolarctobacterium, a bacterium known to decrease inflammation as well as support gastrointestinal health and neurodevelopment, compared to those with the lowest exposure to the toxin. In addition, infants with the highest exposure to PM10 had 80 percent more Dialister, a microorganism associated with inflammation.

“Overall, we saw that ambient air pollution exposure was associated with a more inflammatory gut-microbial profile, which may contribute to a whole host of future adverse health outcomes,” said Alderete.

According to the study’s authors, it’s important to note that racial minorities are at higher risk for toxin exposure. Study’s have shown that racial minorities and those from low-income communities are more likely to live, work, and attend school in areas closer to sources of pollution.

“Our findings highlight the importance of addressing the impact of pollution on disadvantaged communities and point to additional steps all families can take to protect their health,” said Alderete.

Alderete said she hopes this study and future research, will help influence policy makers to distance schools and affordable housing from polluted areas. To avoid toxins in the meantime, Alderete advised that everyone,

  • Avoid walking outside near high-traffic zones
  • Invest in a low-cost air-filtration system
  • Open the windows while cooking
  • For new mothers, breast feed for as long as possible