Study links chronic xanthan gum consumption to colon inflammation

 Xanthan gum is found almost everywhere. This food additive has thickening, stabilizing, and gelling properties and is one of the most widely used by the food industry to adjust the consistency of ice cream, yogurt, cakes, sauces, and gluten-free pasta. It is also used to prepare beverages for people with dysphagia, or difficulty swallowing.

However, a study conducted at the Federal University of São Paulo (UNIFESP) in Brazil raised an important red flag by demonstrating that chronic xanthan gum consumption caused colon inflammation, altered gut microbiota, and led to intestinal barrier integrity loss in an experimental model. In the study, which was supported by FAPESP, rats were fed xanthan gum chronically for ten weeks.

"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 study was described in an article published in the journal PLOS One.

Rischiteli points out that xanthan gum has received more attention from the scientific and clinical communities because it is used in the daily diets of children and older adults with dysphagia. However, it is also present in ultra-processed foods, supplements, and protein shakes. "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.

She explains that xanthan gum is a biotechnology product derived from a fermentation process involving 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.

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, according to the researcher. "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.

Enterocolitis in premature infants

The findings help explain why xanthan gum was previously linked to cases of necrotizing enterocolitis in premature infants in the United States. In 2012, 22 newborns developed intestinal inflammation, which led to the death of intestinal tissue, after consuming formula thickened with the additive. At least three infants died. Since then, the U.S. Food and Drug Administration (FDA) has banned its use in premature infants and recommends avoiding its use in infants altogether.

"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 (https://bv.fapesp.br/en/pesquisador/3632/claudia-maria-da-penha-oller-do-nascimento), a professor at UNIFESP who coordinated the study. 

The study validated the biological model of the metabolic pathway involved in the inflammatory process 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."

Alessandra Rischiteli, nutritionist and speech-language pathologist

The process described in the UNIFESP study confirms the hypothesis of American doctors regarding what occurs in the immature intestines of premature infants. 

The researchers report that consumption of the additive induced an inflammatory state characterized by an increased presence of defense cells (lymphocytes) in the intestinal wall. This process was more intense in groups of rodents that received medium and high doses of xanthan gum. 

Histological analyses confirmed an increased inflammation score, and biochemical tests revealed significant changes in the intestinal barrier.

"This protein [Claudin-2] showed higher expression in the animals' intestinal epithelium, indicating a loss of intestinal barrier integrity," Rischiteli explains.

Additionally, there was an increase in pro-inflammatory markers (the cytokines IL-1β and TNF-α), which reinforced the 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. 

Although the diversity of gut bacteria (microbiota) did not change significantly, chronic consumption of xanthan gum altered the observed microbial balance. For example, it increased the number of bacteria in the phylum Elusimicrobiota, which is associated with inflammatory states.

"This change indicates a state of dysbiosis, even without major alterations in the dominant bacterial groups," she states.