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Key Takeaways
- Xanthan gum is a common food additive used to thicken and stabilize products like ice cream, salad dressings, and gluten-free baked goods.
- Animal studies suggest xanthan gum may cause mild gut inflammation and changes in gut bacteria, but more human research is needed to confirm these effects.
- Most people consume small amounts of xanthan gum, which is unlikely to cause harm.
If you’ve ever read the label on grocery store ice cream or salad dressing, you’ve probably noticed xanthan gum on the ingredient list. It’s often added to packaged foods as a thickener and stabilizer, and new animal research suggests it may cause harm to the gut.
What Is Xanthan Gum?
Xanthan gum is a common food additive that acts as a thickener and stabilizer. It is produced by a bacterium called Xanthomonas campestris, which ferments sugars to produce xanthan, said Sigh Jirapinyo, MD, MPH, the director of bariatric endoscopy at Mass General Brigham and an assistant professor of medicine at Harvard Medical School. The xanthan is then purified, dried, and ground into a powder.
“Interestingly, this bacterium naturally produces a sticky, gum-like substance—which helps explain the name ‘xanthan gum,’” Jirapinyo said.
In packaged foods, xanthan gum helps improve texture, consistency, and stability. For example, she said it can thicken sauces, keep salad dressings from separating, add structure to gluten-free baked goods, and give non-dairy ice cream a smoother, creamier texture.
“Because only a small amount is needed to achieve these effects, it is widely used in packaged foods,” she said.
What the Study Found
A recent study examined what happened when rats consumed varying amounts of xanthan gum daily for 10 weeks. It found that rats that consumed xanthan gum, especially at high doses, had mild inflammatory changes in the colon and altered gut bacteria compared with rats that did not consume it.
The researchers also found changes in the intestinal barrier, the lining that helps protect the body from substances in the gut, said director of dietetics at the University of Georgia.
Overall, gut bacterial diversity remained relatively similar between the groups. “This is an important distinction,” Jirapinyo said. “The types and relative abundance of certain bacteria may have shifted, but the microbiome did not show a broad loss of bacterial diversity, which is often considered one marker of disruption to a healthy gut microbiome.”
And because this was an animal study, Laing said it cannot tell us whether xanthan gum causes inflammation or other health problems in humans. The study was also quite small (only 32 rats), and Jirapinyo said it’s difficult to translate the doses given to rats directly to typical human consumption.
The rats also received xanthan gum every day for 10 weeks, which Jirapinyo said may not reflect how often most people are exposed to it in their usual diet. The findings also weren’t completely consistent across doses or across all measures of inflammation.
What Does Other Research Suggest?
Xanthan gum is not easily digested in the upper part of the digestive tract, so much of it reaches the large intestine, where certain gut bacteria break it down and use it, Laing explained. “Researchers are interested in whether this process affects the gut environment or the body’s immune response, but we don’t yet know whether these changes have meaningful health effects for most people,” she said.
Existing research is minimal. One older, small study in healthy adults found that consuming 15 grams of xanthan gum daily for 10 days increased stool output, bowel movement frequency, and gas. The researchers also found evidence that gut bacteria adapted to and fermented xanthan gum, which may suggest that it is not simply an inert food additive as it passes through the gastrointestinal tract, Jirapinyo said.
More recently, a 2022 study found that bacteria in the human gut microbiome can break down and use xanthan gum, supporting the idea that xanthan gum can interact with and potentially alter the gut microbiome.
Jirapinyo said there have also been reports of necrotizing enterocolitis (NEC), a serious condition in which the intestines become severely inflamed and, in some cases, damaged or die, in premature infants who received a xanthan gum-containing thickener.
“But these were just observational reports and case series, so they cannot establish that xanthan gum caused the condition,” Jirapinyo said. “Premature infants also have very different and much more vulnerable gastrointestinal systems than healthy children or adults, so these findings should not be generalized to the broader population.”
Should You Try to Avoid Xanthan Gum?
Xanthan gum is found in many packaged foods, including ice cream, salad dressings, sauces, soups, beverages, shakes, gluten-free products, and baked goods, Laing said. But only a small amount is needed to achieve its functional effects in food, so she said most people are likely only consuming small amounts in their diet.
Based on the existing evidence, Jirapinyo said that most people don’t need to avoid xanthan gum specifically. However, she said that larger amounts may cause gastrointestinal symptoms, such as gas, bloating, or changes in bowel movements, in some people. If you consistently notice these symptoms after eating foods containing xanthan gum, she said it may be reasonable to reduce your intake and see whether your symptoms improve.
In general, however, rather than focusing on avoiding a single food additive, both Laing and Jirapinyo recommend reducing processed foods and eating more minimally processed, nutrient-dense, whole foods.
“This study raises interesting questions about the long-term effects of xanthan gum on the gut microbiome and intestinal health, but we need well-designed human studies before recommending that people routinely eliminate it from their diets,” Jirapinyo said.