Fedulov and colleagues noted that microplastics are a relatively new class of particles increasingly detected in human tissues. While accumulating evidence suggests potential health risks establishing a direct link to specific diseases remains challenging making causality difficult to confirm.

They pointed to growing data connecting gut microbiome disruptions with the development of asthma and allergies though definitive causal relationships are still unclear. The mechanisms by which airborne environmental particles like microplastics may trigger asthma are not yet fully understood. These exposures have also been shown to influence gut microbial composition adding further complexity to understanding their health impact.

Fedulov and colleagues aimed to investigate these interactions using a mouse model designed to mimic prenatal exposure to three types of airborne particles: concentrated ambient particles diesel exhaust particles and microplastic particles. Their goal was to assess how such exposures influence asthma susceptibility in offspring and to determine whether the gut microbiome plays a mediating role.

In their study pregnant mice were exposed via inhalation to CAP, DEP, or microplastic particles. The offspring later showed an increased tendency to develop asthma exhibiting airway inflammation after being exposed to a normally sub-threshold dose of allergen one that did not cause disease in control animals.

To evaluate the role of the gut microbiome in this heightened susceptibility, the researchers conducted gut microbiome transplants (GMT). They transferred microbiota from neonates that had not been exposed to allergens into microbiota-depleted recipient pups to assess the impact on asthma development.

One of the most striking findings was that gut microbiome transplants from all three exposure groups including microplastics were sufficient to transfer asthma susceptibility to previously unaffected (naïve) recipient mice. When the GMT material was sterilized through radiation it no longer induced asthma-like symptoms suggesting that live microbes are essential for triggering these effects. Similarly administering antibiotics alongside GMT prevented asthma-related symptoms further supporting the involvement of viable bacterial species.

Metagenomic analysis revealed a higher abundance of microbial taxa such as Butyribacter Acetatifactor Coproplasma Kineothrix and members of the Lachnospiraceae family in the CAP and DEP exposure groups. Analysis for the microplastic group is still ongoing. Functional assessments indicated that these bacteria are producers of short-chain fatty acids (SCFAs) particularly acetate and butyrate.

Source: https://www.hcplive.com/view/prenatal-exposure-microplastics-impacts-microbiome-increases-asthma-risk