New Delhi, Dec. 17 -- Air pollution has long been associated with lung problems and heart disease. A study from UCLA Health suggests that breathing ultrafine air pollution affects not only the lungs and bloodstream. It may quietly disrupt the gut first - and that disruption could make heart disease worse. The research, published in Environment International, examined how ultrafine particulate matter affects the body beyond the usual suspects.

UCLA Health scientists exposed mice to ultrafine air particles over a 10-week period. The exposure was not constant. It ran six hours a day, three days a week. The goal was to mirror real-life exposure, not create extreme conditions. Another group of mice breathed clean, filtered air.

The differenc...