Brazil study raises red flag as daily xanthan gum intake inflames colon in rats

Brazilian researchers are drawing fresh attention to xanthan gum after a rat study linked long-term intake to gut problems. The additive is widely used to thicken or stabilize foods such as ice cream, yogurt, sauces, gluten-free pasta, and beverages made for people with swallowing difficulties.

What happened?

A 10-week experiment at the Federal University of São Paulo, or UNIFESP, found that rats regularly given xanthan gum developed colon inflammation, changes in the makeup of gut bacteria, and signs of a weakened intestinal barrier. The study appeared in PLOS One and was reported by News-Medical.

Alessandra Rischiteli, the nutritionist and speech-language pathologist who led the study, said the findings should not be treated as a warning against every occasional exposure.

"This isn't about demonizing xanthan gum. Rather, it's about emphasizing the need to invest in translational studies involving humans. It's possible that occasional use in small amounts as an additive doesn't harm health. The concern is with daily use as an ingredient and the cumulative effect of the thickener."

The evidence pointed toward an inflammatory response. The rats had more lymphocytes in the intestinal wall, higher inflammation scores, and elevated pro-inflammatory markers, including IL-1-beta and TNF-alpha, after being given xanthan gum. Their gut bacteria remained broadly diverse, but the overall mix shifted, including an increase in Elusimicrobiota, which has been associated with inflammatory states.

Rischiteli said the effect appears to involve damage to the gut lining. "Xanthan gum is reactive and opens the intestinal barrier, altering a protein [Claudin-2] that's responsible for regulating permeability between intestinal cells, which triggers an inflammatory cascade."

Why does it matter?

Xanthan gum is used well beyond a few specialty products. It shows up in ultra-processed foods, supplements, and protein shakes, and it is also added to drinks made for people with dysphagia, or difficulty swallowing.

The findings in rats do not establish that humans will experience the same effects. Still, they echo earlier concerns. In 2012, 22 premature infants in the United States developed intestinal inflammation after consuming formula thickened with xanthan gum, and at least three died.

Claudia Oller, the UNIFESP professor who coordinated the study, said, "Until then, the link between xanthan gum and the disease in infants was merely a clinical hypothesis or an empirical observation. This study on rats proved causality — that is, that xanthan gum does cause inflammation."

What can I do?

If you eat a lot of packaged foods, check ingredient labels and see how often xanthan gum shows up over the course of your day. The concern raised by this study is not a single serving but repeated exposure and possible cumulative effects.

If you rely on thickened drinks or foods because of dysphagia, experts are not suggesting that people stop using necessary products on their own. Instead, speak with a doctor, registered dietitian, or speech-language pathologist about alternatives, monitoring, and digestive symptoms.

U.S. regulators no longer permit xanthan gum for premature infants and recommend avoiding it in infants altogether.

Researchers are taking a closer look at how common additives affect the gut, inflammation, and health, not just whether they improve texture or shelf life.

Rischiteli said the goal for some patients is harm reduction rather than abrupt avoidance. "For patients with dysphagia who depend on thickeners to eat and stay hydrated and cannot tolerate natural alternatives, such as cornstarch, the priority is minimizing damage. Based on the results of the study, the recommendation is to monitor gut health and adopt strategies to protect the gut, such as using probiotics."

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