The possible effects of common air pollutants on the pathophysiology of functional gastrointestinal disorders: A narrative review

There are more than seven million premature deaths every year linked to air pollution effects. The critical hazards of exposure to air pollution are the increased risk of respiratory and cardiovascular diseases, which can boost morbidity and mortality. Besides, ingested pollutants can cause gastrointestinal (GI) diseases. Functional GI disorders (FGIDs) are called gut-brain interaction disorders that influence approximately one out of every four people and have negative effects on life quality, work productivity, and medical costs. Intestinal inflammation, gut microbiota, and GI motility are the three important factors in the pathogenesis pathways of these disorders. This literature aimed to clarify the link between air pollution exposure and the pathophysiology of FGIDs. This study was conducted based on published studies in English using scientific databases, such as PubMed, Embase, Web of Science, and Google Scholar, from 1990 to 2023. We used various combinations of relevant keywords, such as air pollution, air pollutant, FGID, gut microbiota, and gut inflammation. The findings indicated that air pollution can contribute to the etiology of FGIDs through dysbiosis and intestinal inflammation. In addition, air pollution may alter the composition and diversity of gut microbiota, which in turn can play major roles in the development of these disorders. In addition to the steps taken by the government to tackle air pollution, there are some recommendations to prevent the negative effects of air pollution exposure, such as the consumption of biotics in a diet.