Antibacterial soaps, toothpaste not as harmful as thought

An agent used in many antibacterial products might not be as harmful as some had feared, according a new study.

Triclosan, an antimicrobial and antifungal agent found in many consumer products ranging from hand soaps to toys and even toothpaste, was thought to rapidly disrupt bacterial communities found in the gut. Now, the study found that it does not have a major influence.

"There are a lot of people who are fearful of triclosan, but we didn't find anything to support that concern in our study," said principal investigator Julie Parsonnet, adding, "When you throw most antibiotics into humans, they are an atom bomb on the microbiota, but we found that when people are exposed to triclosan through normal household products, it does not cause a major blow to our microbial ecosystems."

In the new double-blind, randomized, crossover study, Stanford researchers randomized 13 healthy individuals to use household and personal care products (toothpaste, hand soap, and dishwashing liquid) that either contained triclosan or did not contain triclosan for four months. After four months, individuals were switched to the alternative arm for four months.

The researchers analyzed blood samples for metabolic and endocrine markers, urine samples for triclosan, and stool and oral samples for microbiome composition.

While triclosan-containing products had a significant impact on the levels of triclosan found in urine, exposure to triclosan did not have a significant impact on the oral or gut microbiome or on a panel of metabolic markers.

"We found that some organisms were changed a little bit, but there was no major blow to oral flora or gut flora," said Dr. Parsonnet. "For people who are very fearful of triclosan, this study should be reassuring.

The study appears in mSphere.