Animal Study Demonstrates How Triclosan Can Trigger Gut Inflammation

Scientists have identified bacteria and specific bacterial enzymes that trigger harmful effects of triclosan, an antimicrobial agent found in thousands of consumer products; moreover, the study suggests these enzymes can be blocked from driving intestinal damage.

Triclosan is an antimicrobial ingredient present in more than 2,000 consumer and industrial products. It is a ubiquitous environmental contaminant and a top-ten US river pollutant.

In 2016, the USA Food and Drug Administration (FDA) removed triclosan from over-the-counter handwashing products.

However, it remains approved for use in a wide range of products such as toothpaste, mouthwash, hand sanitizers, cosmetics, and toys.

Health problems connected to triclosan include increased risks of allergies and asthma, altered immune responses, disruption of endocrine functions, and increased development of antibiotic resistance.

Specific to the gastrointestinal tract, researchers recently showed that exposure to triclosan, at human-relevant doses, increased the severity of colitis and exaggerated the development of colitis-associated colorectal cancer in mouse models.

The finding supported that triclosan could be a potential risk factor for inflammatory bowel disease and associated diseases.

“By identifying the culprit bacteria, new approaches could be developed for the diagnoses, prevention and treatment of inflammatory bowel diseases,” said Professor Matthew Redinbo, a researcher in the Departments of Chemistry, Biochemistry, Microbiology and Genomics at the University of North Carolina at Chapel Hill.

Professor Redinbo and colleagues connected specific gut microbial enzymes, notably gut microbial beta-glucuronidase (GUS) proteins, with triclosan and showed these enzymes drive triclosan to wreak havoc in the gut.

Knowing which bacterial proteins were the culprits, they used a microbiome-targeted inhibitor to block triclosan processing in the gut.

Blocking this process in mice prevented damage to the colon and symptoms of colitis, a form of inflammatory bowel disease.

The study provides new clues about management of inflammatory bowel disease among the growing number of people diagnosed with the disease.

Inflammatory bowel disease can be managed for long periods of time only to flare up out of seemingly nowhere.

The authors suggest the need for better understanding of the impact of environmental chemicals on gut health.

“The safety of triclosan and related compounds should be reconsidered given their potential for intestinal damage,” they said.

The results were published in the journal Nature Communications.