Cyclamate Worsened Colitis in Mice, New Study Reports

A mouse study published online on September 21, 2026, in the journal Food & Function reports that chronic exposure to the sweetener sodium cyclamate made chemically induced colitis worse. According to the abstract, mice given cyclamate on top of the colitis-inducing chemical had greater disease severity, shifts in some gut bacteria and lower levels of the gut-barrier proteins Mucin-2 and Occludin. Cyclamate is banned in US food under Food and Drug Administration (FDA) rules, so the study matters mainly for imported products and travel.

Key Takeaways

• A mouse study published online on September 21, 2026, in Food & Function reports that chronic sodium cyclamate exposure worsened colitis induced by the chemical dextran sulfate sodium (DSS).
• The abstract reports higher levels of Bacteroides and Klebsiella bacteria and lower levels of the barrier proteins Mucin-2 and Occludin and the antioxidant enzymes GPX2 and TXN2.
• Under 21 CFR 189.135, food containing any added or detectable level of cyclamate is deemed adulterated in the US.
• The study used mice with chemically induced colitis and does not show that cyclamate causes inflammatory bowel disease in people.
• For US shoppers, the practical relevance is imported products: cyclamate should not appear on the ingredient list of a legally sold US food.

What happened

On September 21, 2026, a study by researchers at Tianjin University of Traditional Chinese Medicine and Tianjin Huanhu Hospital was published online in the Royal Society of Chemistry journal Food & Function. The peer-reviewed study (doi:10.1039/d6fo02315k; PubMed 42764709) tested chronic sweetener exposure in a mouse model of gut inflammation.

The work was funded by the China Postdoctoral Science Foundation under grant award 2026T191050. The researchers asked whether chronic sodium cyclamate exposure would worsen colitis induced by dextran sulfate sodium (DSS), a chemical researchers use to create colitis-like gut inflammation in mice. The question was whether cyclamate makes already-induced inflammation worse, not whether it causes colitis on its own.

The full paper is paywalled, so everything reported here comes from the abstract.

What changed

According to the abstract, the team used disease phenotyping, 16S rRNA gene sequencing of gut bacteria, targeted measurements of short-chain fatty acids (SCFAs) and bile acids, metabolomics, lipidomics, discovery proteomics and independent western blot validation.

The core comparison was between mice given DSS alone and mice given DSS plus chronic sodium cyclamate. The abstract reports that, relative to DSS alone, the DSS + Cyclamate mice had greater disease severity and higher abundances of Bacteroides and Klebsiella. Lactobacillus and Muribaculaceae showed only nonsignificant downward trends in the direct comparison.

Western blotting confirmed lower levels of Mucin-2, Occludin, glutathione peroxidase 2 (GPX2) and thioredoxin 2 (TXN2) in the DSS + Cyclamate mice. As general background, Mucin-2 is a main component of the gut's protective mucus layer, and Occludin is a tight-junction protein that helps seal the gut lining. GPX2 and TXN2 are antioxidant enzymes.

The researchers also found higher total protein kinase C-beta (PKC-beta) in the DSS + Cyclamate mice. Changes in hypoxanthine, diacylglycerols (DAG) and cyclohexylamine "supported testable hypotheses," in the abstract's words. Short-chain fatty acids and colonic bile acids did not differ significantly between the two groups, which the authors say "provided contextual information rather than evidence for a primary cyclamate-specific pathway."

The authors concluded: "These findings indicate that cyclamate exposure can aggravate DSS-induced colitis and identify microbial, epithelial, redox, and lipid-associated processes for causal validation." In other words, the mechanisms they list are candidates that still need to be tested for cause and effect.

Who is affected

Shoppers buying foods made for the US market should not encounter sodium cyclamate. Under the federal ban, a food with any added or detectable level of cyclamate is considered adulterated.

The study is more relevant to people who buy imported packaged foods or drinks, or who travel. We have not verified which countries allow cyclamate or at what limits, so check the ingredient list rather than assuming.

People living with Crohn's disease or ulcerative colitis often watch for additives that might affect their gut. This single mouse study generates hypotheses; it is not clinical guidance, and anyone managing a digestive condition should talk to their own clinician.

What it means for shoppers

For US consumers, legally sold domestic foods should not contain cyclamate. If an imported product lists a cyclamate salt, that conflicts with the US ban.

Names to look for on an imported product's ingredient list:

• Sodium cyclamate
• Calcium cyclamate
• Cyclamic acid
• Potassium cyclamate or magnesium cyclamate
• E952, the additive's E-number on labels that use E-numbers

For how sweeteners that are permitted in the US show up on scanned drinks, see Sweetener Stacks: 4 Scanned Drinks That Blend Sweeteners.

Other recent sweetener studies we have covered include Acesulfame K at High Doses Disrupts Zebrafish Larvae and Sucralose and Gut Bacteria: New Review of 10 Human Trials.

The background

Federal regulation describes cyclamates as having "a sweet taste 30 to 40 times that of sucrose." The US ban rests on an order published in the Federal Register on October 21, 1969.

Today the ban is codified at 21 CFR 189.135, which states that food containing any added or detectable level of cyclamate is deemed adulterated. FDA's sweeteners page says: "The FDA prohibits the use of cyclamates and their salts (such as calcium cyclamate, sodium cyclamate, magnesium cyclamate, and potassium cyclamate) in the U.S."

What to watch next

The study has clear limits:

• It was done in mice with chemically induced colitis; it does not show that cyclamate causes inflammatory bowel disease in people.
• The abstract does not give the cyclamate dose, how it was given, the exposure length or the number of mice per group.
• The abstract does not report whether cyclamate alone, without DSS, caused any gut inflammation.
• Because the primary journal article remains paywalled, the full methods and the conflict-of-interest statement were not available to us.
• We found no regulatory response to this study from the FDA or any other agency.

Follow-up work would need to show whether these effects depend on dose, whether they occur without DSS, and whether the candidate mechanisms are causal.