Triclosan found in toothpaste and cosmetic products could trigger gut inflammation, flags study

12 Jan 2022 --- Triclosan (TCS), a high-volume chemical used as an antimicrobial ingredient in consumer products, such as toothpaste and cosmetics, may induce colitis and have a harmful impact on the gut microbiome. Colitis is an inflammation of the inner lining of the large intestine – colon.

This is according to a mouse study from the University of North Carolina, the University of Massachusetts Amherst and Hong Kong Baptist University. The researchers found that specific bacteria and enzymes triggered triclosan’s harmful effects.

Additionally, studies in mice suggest these bacterial enzymes can be blocked from driving intestinal damage.

“After TCS exposure through brushing teeth using TCS toothpaste, TCS enters the GI tract. Then it is converted to a biologically inactive metabolite called TCS-glucuronide (TCS-G),” Guodong Zhang, associate professor, food science department at the University of Massachusetts, tells PersonalCareInsights.

“Eventually, TCS-G can enter the colon tissues and interact with gut bacteria in the colon tissues and can be converted back to the parent compound TCS, which has pro-inflammatory effects.”

The study provides new clues about the management of Inflammatory bowel disease (IBD) among the growing number of people diagnosed with the disease. IBD can be managed for long periods, but it can flare up out of seemingly nowhere.

Blocking triclosan processing
The study 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.Triclosan remains a prevalent ingredient added to cosmetics, yoga mats, athletic clothes and gear to reduce bacterial contamination.

The researchers note that previous research has shown triclosan’s toxicity, but the new study published in the journal of Nature Communications provides a closer look at the changes caused in the gut’s microscopic population.

“By identifying the culprit bacteria, new approaches could be developed for the diagnoses, prevention and treatment of inflammatory bowel diseases,” adds Matthew Redinbo, chemistry and microbiology professor at the UNC-Chapel Hill College of Arts & Sciences and UNC School of Medicine.

After identifying which bacterial proteins were harmful to the gut, 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.

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

Regulations concerning triclosan
Previously, triclosan was widely available in antibacterial soaps marketed to consumers.

However, in 2016, the Food and Drug Administration ordered it to be removed from handwashing products used in homes and hospital settings because of concerns it contributed to more resistant bacteria.The researchers found that by reactivating triclosan in the mouse gastrointestinal tract, microbial enzymes caused colitis.

“We previously reported that exposure to triclosan at human exposure relevant doses increases the risks of colitis and colon cancer in mouse models,” adds Zhang.

“After the publication of this paper, in 2019, Colgate removed TCS from its products through TCS remains approved by the FDA to use in toothpaste products and other products.”

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

But triclosan remains a prevalent ingredient added to cosmetics, yoga mats, athletic clothes and gear to reduce bacterial contamination. It’s also routinely used in many kinds of toothpaste – with FDA approval – since it has been found to prevent gingivitis.

Previously, Whole Foods Market stated that triclosan, among other ingredients such as parabens and microbeads, were banned from its beauty and baby care products. This move was made to meet clean beauty claims.

By Nicole Kerr