Unexplained stomach issues affecting patients? It could be poor air quality

By Anastasia Climan, RDN, CD-NFact-checked by Barbara BekieszPublished January 7, 2026


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When air quality worsens, inflammation and immune activation can increase, which may contribute to bloating, irregular bowel movements, or IBS-like symptoms.

— Kathleen Benson, CSSD, CPT, RDN

A recent news story from India highlighted an emerging health concern related to the dense air pollution in cities like Delhi. Toxic air has long been associated with risks like lung cancer. But experts are now warning about impacts beyond the respiratory system, including digestive diseases. []

“It makes a lot of sense that poor air quality would affect digestion because pollutants can influence immune function, and most of our immune system is located in the digestive tract,” says Kathleen Benson, CSSD, CPT, RDN, of VNutrition. “When air quality worsens, inflammation and immune activation can increase, which may contribute to bloating, irregular bowel movements, or IBS-like symptoms."

Here’s why physicians may need to start looking beyond food when figuring out the cause of their patients’ digestive woes.

Related: Here’s how a healthy gut lets you live a longer, healthier life

From the lungs to the intestines

A study from China found an association between chronic exposure to air pollution and non-neoplastic digestive system diseases. []

Air pollutants raised the risk of the following ailments in adults 45 and older []:

  • Intestinal infections

  • Esophageal disease

  • Gastritis

  • Appendicitis

  • Peptic ulcers 

  • Liver disease

  • Gastrointestinal bleeding

  • Non-infectious gastroenteritis

As particles enter the lungs, they kick off an inflammatory cascade that travels through the bloodstream to the intestines, promoting permeability (leaky gut). [] Gas pollution also has direct effects on the digestive system when polluted air is swallowed. []

Food and water quality matters

Global rates of gastrointestinal problems can range from 14% to 54%, and even 60% to 70% in India in some studies. []

Destini Moody, RD, CSSD, LD, of Live it Up, calls the above 70% statistic a “shocking number.” But "we must also account for the fact that Indian cuisine contains a large number of inflammatory foods, like saturated fats and refined sugar, that can irritate the gut," she says.

In the Chinese study, contaminated food and water were the biggest contributors to digestive problems in high-air-pollution areas. []

“Poor air quality is also associated with poor water quality as pollutants from the air, like mercury and sulfur, can end up in drinking water and contaminate the fish that swim in polluted rivers,” Moody says. “Contaminated drinking water that’s consumed consistently can cause stomach issues, but populations like those in India who do not eat red meat and can have fish-focused diets could possibly be consuming gut-damaging compounds from both sources.”

Related: The magic gut health pill your patients shouldn't be taking

Taking in the overall impact

Benson said she tries to take a bird’s eye view. “I like to zoom out and look at the bigger picture: If someone is constantly exposed to pollution, what else is going on in their day-to-day environment?” she asks. “Are they commuting long hours with limited access to nutrient-dense meals? Are they living in a food desert without consistent fruit and vegetable availability? Are stress and sleep being affected?” 

She continues: “Air quality might be one factor, but lifestyle and environment often overlap, and those layers combined may influence digestion."

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