FUKUOKA, Japan – New research suggests vaping could disrupt the body in unexpected ways, even when nicotine isn’t involved.
In a recent study, researchers at Kyushu University in Japan found exposure to e-cigarette vapor changed gut bacteria and behavior in zebrafish, a species frequently used in scientific research because it shares roughly 80% of the genes linked to human diseases.
Scientists exposed the fish to e-cigarette vapor in their water for seven days, simulating typical vaping conditions. They found the heated liquids released harmful byproducts, including formaldehyde and acetaldehyde, which are classified as carcinogens and are known to cause respiratory and skin irritation.
More striking, researchers said, was what happened to the gut microbiome.
“The gut microbiome is sensitive to environmental exposure, and its balance and stability are closely linked to overall health,” said Tse Ka Fai William, an associate professor in Kyushu University’s Faculty of Agriculture.
After exposure, some bacteria declined while others — particularly microbes known for breaking down toxins — became dominant.
“The changes suggest that the fish, or rather the bacteria, can ‘feel’ the toxic substances in the water and want to adapt to the new environment,” said study author Thi Ngoc Mai Dong.
Because gut bacteria are closely tied to brain function, researchers also examined behavior. They found fish exposed to the vapor-contaminated water had altered escape responses, suggesting possible neurological effects.
“The increasing use of e-cigarettes worldwide has raised concerns regarding their long-term health impacts, particularly due to the complex chemical profile generated during e-liquid vaporization,” the authors wrote.
According to the World Health Organization, at least 15 million adolescents between 13 and 15 years old use e-cigarettes.
Researchers caution that results from animal studies cannot be directly applied to humans. Still, they say the findings add to growing questions about the safety of vaping.
Previous studies have linked e-cigarette use to potential risks including cardiovascular problems, organ damage and brain issues like dementia. Other research suggests vaping may immediately affect how well blood vessels function , even without nicotine.
