How Triclosan Harms Your Gut Microbiome

A new study conducted in mice demonstrates precisely how triclosan*, an antimicrobial found in many household and personal care items, including cosmetics, toothpastes, shampoos, facial cleansers, toys and thousands of other products including toothbrushes, body washes, hand creams, deodorants, mops, shower curtains, disinfectant sprays, towels, yoga mats and athletic wear, can trigger gut inflammation–which as we all know by now, can lead to some serious health problems like IBD.


Increasingly, research has linked triclosan with alterations of the gut microbiome and gut inflammation. This new study examined potential avenues for combating damage to the intestine–including from chemicals in clothing, personal care products and household products. The findings suggest new approaches for improving the diagnosis, prevention and treatment of inflammatory bowel disease (IBD).

Study overview

“An international team of researchers identified the bacteria, and even specific enzymes, that trigger triclosan’s harmful effects. Moreover, studies in mice suggest these bacterial enzymes can be blocked from driving intestinal damage.

Previous research has shown triclosan’s toxicity**, but the new study provides a closer look at the changes caused in the gut’s microscopic population…

Researchers 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, the team 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 IBD among the growing number of people diagnosed with the disease. (IBD can be managed for long periods of time only to flare up out of seemingly nowhere…the researchers suggest the need for better understanding of the impact of environmental chemicals like triclosan on gut health.)”


Triclosan appears to be readily absorbed in the gastrointestinal tract, leading the scientists to write, “the safety of triclosan and related compounds should be reconsidered given their potential for intestinal damage.”

*Triclosan was previously widely available in antibacterial soaps marketed to U.S. consumers. But in 2016, the U.S. Food and Drug Administration (FDA) ordered it removed from handwashing products used in homes and hospital settings because of concerns it contributed to more resistant bacteria. However, despite this ban, triclosan (and the commercial version called “microban”) remain ubiquitous as an ingredient added to many, many personal care products, cosmetics, disinfectants and household items.

**See our previous publications of scientific studies on health problems connected to triclosan:

Antimicrobial Additive Triclosan Linked to Fatty Liver Disease

Triclosan Linked with Broken Bones in Women: Study

The UTI-Triclosan Connection

Avoid These Chemicals in Cosmetics and Personal Care Products

Chemicals in personal care products linked with early puberty in girls: study

Common chemical in your bathroom linked with antibiotic resistance

Journal Reference: Jianan Zhang, Morgan E. Walker, Katherine Z. Sanidad, Hongna Zhang, Yanshan Liang, Ermin Zhao, Katherine Chacon-Vargas, Vladimir Yeliseyev, Julie Parsonnet, Thomas D. Haggerty, Guangqiang Wang, Joshua B. Simpson, Parth B. Jariwala, Violet V. Beaty, Jun Yang, Haixia Yang, Anand Panigrahy, Lisa M. Minter, Daeyoung Kim, John G. Gibbons, LinShu Liu, Zhengze Li, Hang Xiao, Valentina Borlandelli, Hermen S. Overkleeft, Erica W. Cloer, Michael B. Major, Dennis Goldfarb, Zongwei Cai, Matthew R. Redinbo, Guodong Zhang. Microbial enzymes induce colitis by reactivating triclosan in the mouse gastrointestinal tract. Nature Communications, 2022; 13 (1).  DOI: 10.1038/s41467-021-27762-y