Xanthan gum–a common food thickener–increased intestinal inflammation and signs of a leakier gut in rats. Digest
Xanthan gum is a food additive used to thicken and stabilize many processed foods. Although it is widely used, animal research has raised questions about whether regular intake could affect gut health. A new study examined whether xanthan gum could promote inflammation and alter the intestinal barrier.
You just missed this in your inbox
Every other week our Premium Members received this exact study plus Rhonda's practical commentary and 8+ other hand-picked papers.
The study included 32 adult male rats divided into four groups. For 10 weeks, one group ate a control diet, while the other three ate the same diet supplemented with 462.5, 925, or 1,850 milligrams of xanthan gum per kilogram of food. After the feeding period, researchers examined tissue from the lower part of the colon under a microscope and looked for proteins tied to inflammation and intestinal barrier function. They also analyzed gut bacteria and tracked food intake, body weight, and blood markers of metabolic health.
- Microscopic examination showed more inflammation, including more immune cells in the intestinal wall, in the middle- and highest-dose groups than in the control group, while the group with the lowest dose showed no clear difference.
- Staining of thin intestinal tissue slices showed that a greater proportion of cells contained TNF-α, a protein involved in inflammatory responses, at all three xanthan gum doses. Claudin-2, which forms channels between intestinal cells and can make the intestinal lining more permeable, was also found in more cells and across a wider area of the tissue in rats given xanthan gum.
- A separate test measuring total protein levels found higher IL-1β, another protein involved in inflammatory responses, only at the middle dose, while Claudin-2 and ZO-1, the latter of which helps organize the seals between intestinal cells, rose only at the lowest dose.
- Xanthan gum caused only a small change in gut bacteria. The variety of bacteria and how much of each common type was present remained similar between the diet groups.
- Body weight and blood markers of metabolic health did not clearly differ. The groups had similar food intake, weight gain, and body fat. Blood sugar and measured blood fats, including triglycerides and cholesterol, were also similar.
Xanthan gum may activate immune cells in the wall of the colon. Once activated, these cells can release proteins that attract additional immune cells into the tissue. As more immune cells accumulate and become activated, the tissue can become increasingly inflamed. The same signals can also affect the intestinal barrier, making it more permeable and allowing water and other dissolved substances to cross the intestinal lining more easily. Substances reaching the tissue beneath the lining could then further activate immune cells, reinforcing the inflammation. Because gut bacteria changed little overall, a broad disruption of the bacterial community is less likely to be the main explanation.
The study did not directly test whether the intestinal barrier became more permeable, and the inconsistent dose patterns make it less certain how confidently the observed changes can be attributed to xanthan gum. Because the study was conducted in rats, it also remains unclear whether the same effects occur in people. Confirmation in human studies would strengthen the case for greater caution around frequent intake of xanthan gum and the ultra-processed foods that often contain it. In Aliquot #111, I explain why ultra-processed foods and their additives are harmful.