A widely used food thickener may have more complex effects on the gut than previously recognized.
Xanthan gum helps give ice cream, yogurt, sauces, cakes, and gluten-free pasta their familiar texture. Valued for its thickening, stabilizing, and gelling properties, it is among the food industry’s most widely used additives. It also helps make liquids safer to swallow for people with dysphagia, a condition that causes difficulty swallowing.
Research from the Federal University of São Paulo (UNIFESP) in Brazil, however, raises questions about the effects of prolonged consumption. Rats that received xanthan gum for ten weeks developed colon inflammation, changes in their gut microbiota, and reduced intestinal barrier integrity. The study was supported by FAPESP.
“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,” explains Alessandra Rischiteli, the nutritionist and speech-language pathologist who conducted the study. The findings were published in PLOS One.
Daily exposure raises broader concerns
Scientific and clinical interest in xanthan gum has increased partly because children and older adults with dysphagia may consume it every day, Rischiteli notes. The additive is also common in ultra-processed foods, protein shakes, and supplements. “Here, once again, the guidelines set forth in the Dietary Guidelines for the Brazilian Population – which recommend avoiding ultra-processed foods and foods high in additives – are relevant,” she says.
Xanthan gum is produced through biotechnology by fermenting material with the bacterium Xanthomonas campestris. “It’s a plant pathogen that, in nature, infects a variety of plants and can be observed when cabbage or kale, for example, begin to spoil,” she says.
Some people with dysphagia rely on thickeners to consume enough food and liquids, especially when they cannot tolerate natural options such as cornstarch. For these patients, Rischiteli says the goal should be to reduce possible harm rather than simply remove a necessary product. “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,” she states.
Infant cases gain a possible explanation
The results may help clarify earlier reports connecting xanthan gum with necrotizing enterocolitis in premature infants in the United States. This serious disease causes intestinal inflammation that can lead to tissue death.
In 2012, 22 newborns developed the condition after receiving formula thickened with xanthan gum, and at least three died. The U.S. Food and Drug Administration (FDA) subsequently prohibited its use in premature infants and advises against using it in infants more generally.
“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,” says Claudia Oller, a professor at UNIFESP who coordinated the study.
The intestinal barrier begins to weaken
The researchers also examined the biological pathway through which the inflammatory response developed in the colon. “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,” Rischiteli explains.
According to the researchers, this process supports the mechanism previously proposed by American physicians to explain what may occur in the immature intestines of premature infants.
Rats fed the additive developed an inflammatory state marked by greater numbers of lymphocytes, immune defense cells, within the intestinal wall. The response was strongest among animals receiving medium and high doses of xanthan gum.
Microscopic tissue examinations found higher inflammation scores, while biochemical testing identified significant disruption of the intestinal barrier.
“This protein [Claudin-2] showed higher expression in the animals’ intestinal epithelium, indicating a loss of intestinal barrier integrity,” Rischiteli explains.
The rats also had elevated levels of the pro-inflammatory cytokines IL-1β and TNF-α, providing further evidence of an inflammatory response. “TNF-alpha, in particular, is associated with the death of cells lining the intestine [epithelium] and the development of inflammatory diseases,” she says.
Gut bacteria shift toward dysbiosis
Long-term xanthan gum consumption did not significantly reduce the overall diversity of the rats’ gut microbiota. It did, however, change the balance among microbial groups.
One shift involved an increase in bacteria belonging to the phylum Elusimicrobiota, which has been associated with inflammatory conditions.
“This change indicates a state of dysbiosis, even without major alterations in the dominant bacterial groups,” she states.
Reference: “Xanthan gum intake modifies the colon microbiota profile and causes mild colon inflammation in rats” by Alessandra B. Silva Rischiteli, Artur Francisco Silva-Neto, Paloma Korehisa Maza, Valter Tadeu Boldarine, Daniel Araki Ribeiro, Carolina Foot Gomes Moura, Marina Gomes Galvani, Raquel Galvão Figuerêdo, Giovana Jamar, Mariana de Moura Dias, Larissa Casemiro Pacheco Monteiro, Tiago Antonio de Oliveira Mendes, Lila Missae Oyama, Daniela Caetano Gonçalves and Claudia Maria Oller do Nascimento, 15 April 2026, PLOS ONE.
DOI: 10.1371/journal.pone.0347232
Funding: Fundação de Amparo à Pesquisa do Estado de São Paulo
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