A new American study has pointed to the harmful effects of air pollution on the development of the intestinal microbiome of infants. We take stock.
- The intestinal microbiota is a set of microorganisms living in the digestive tract of humans and animals. It contains many bacteria that are very important for health.
- Air pollution could impact the proper development of this organism in newborns.
Poor air quality has many health consequences: eye irritation, airway obstruction, asthma attacks, increased cardiovascular and respiratory problems. In infants, air pollution can also have detrimental impacts on their gut microbiome, according to a new study from the University of Colorado at Boulder (USA). These deleterious effects could increase the risk of allergies, obesity and diabetes in the youngest and could influence the proper development of their brain.
The key role of the gut microbiome
These works, published in review Gut Microbes, were the first to highlight the link between inhaled pollutants, from traffic, forest fires or even industry, and the evolution of microbial health during the development of a newborn. “The microbiome plays a role in almost every physiological process in the body”, said Maximilian Bailey, one of the study’s authors and a medical student at Stanford University.
For the purposes of the study, the researchers analyzed fecal samples from 103 healthy, Latino infants who had been recruited for breast milk research in Southern California. The samples were studied by genetic sequencing. The scientists also looked at data from the US Environmental Protection Agency’s Air Quality System. They assessed exposure to PM2.5 and PM10, fine inhalable particles from factories, forest fires and construction sites in particular, and nitrogen dioxide (NO2), a gas widely emitted by cars.
Air pollution increases the risk of inflammation
According to the results, infants highly exposed to PM2.5 are 60% less likely to develop Phascolarctobacterium, a bacterium found in the gut microbiome that can reduce the risk of inflammation, improve gastrointestinal health and promote neurological development. “Overall, we found that exposure to ambient air pollution was associated with a more inflammatory gut microbial profile, which may contribute to the onset of adverse health effects”said Tanya Alderete, lead author of the study and assistant professor of integrative physiology at the University of Colorado.
Newborns are among the most vulnerable populations to the dangers of air pollution. Their gut microbiome is forming and they breathe faster than an adult, so they inhale more polluted air. “This makes early life a critical passage where exposure to air pollution can have disproportionate deleterious effects on health”can we read in the research.
To limit its exposure to indoor and outdoor pollutants, the team unveiled several recommendations. Scientists advise against, for example, walks near high traffic areas and avoid cooking with closed windows. Over the next few years, further studies are needed to determine the potential lasting implications of changes in the gut microbiome in children.