Breathing “dirty” air, basically polluted air, can help weight gain? The answer is yes according to a new study published in Environment International and carried out by researchers at the University of Colorado Boulder.
According to the researchers, in fact, polluted air can promote obesity, diabetes, gastrointestinal disorders and other diseases of a chronic nature by modifying the intestinal microbiome, the bacteria that live inside our intestines.
This is the first study to find a link between human intestinal microbiome and air pollution.
What is particularly dangerous is the gaseous ozone present in the atmosphere: young adults exposed to this type of pollution show a lower diversity of bacteria, which is not positive as far as the microbiome of the intestine is concerned: too little diversity of the species of bacteria present in the intestine has already been associated in the past with diseases and in general with things that are not positive for the human body.
Tanya Alderete, professor of integrative physiology and one of the authors of the study, says that some of the changes that can promote diseases such as obesity or diabetes can be traced back to changes in the intestine.
Previous studies by the same researcher had already shown that air pollution can also compromise the ability to regulate blood sugar and this indirectly increases the risk of obesity.
In addition, other research had shown that more visits to hospital emergency rooms were made on slimming pollution days.
For this new study, researchers analyzed faecal samples from 101 adults from southern California. In addition, the researchers also examined data from air monitoring stations located near the homes of individuals whose faeces were examined.
Of all the pollutants analyzed, ozone appears to have the greatest impact on the intestine, specifically an impact on the diversity of bacteria. In addition, the subjects most exposed to ozone in the atmosphere also had more Bacteroides caecimuris bacteria. This bacterium has already been linked to higher levels of obesity in the past.
“Ozone is probably changing the environment of the intestine to favour some bacteria over others, and this may have health consequences,” says Alderete, who also wants to carry out a wider study to explore these effects in other types of dipopulations such as children.