A study from the Federal University of São Paulo UNIFESP in Brazil, supported by FAPESP, found that chronic consumption of xanthan gum caused colon inflammation, altered gut microbiota, and damaged intestinal barrier integrity in rats over a ten-week period. The findings help explain previous links…
A new study conducted by researchers at the Federal University of São Paulo UNIFESP in Brazil has found that long-term consumption of xanthan gum, a widely used food additive, can cause colon inflammation, disrupt gut microbiota, and compromise the integrity of the intestinal barrier. The findings were published in the journal PLOS One and supported by the São Paulo Research Foundation FAPESP .
Xanthan gum is a common additive found in many processed foods due to its thickening, stabilizing, and gelling properties. The food industry uses it to adjust the consistency of products such as ice cream, yogurt, cakes, sauces, and gluten-free pasta. It is also used in beverages designed for people with dysphagia, or difficulty swallowing.
The research team, led by nutritionist and speech-language pathologist Alessandra Rischiteli, fed rats a diet containing xanthan gum for ten weeks. This chronic exposure led to measurable negative effects on the animals' digestive health. According to Rischiteli, the study was not intended to demonize xanthan gum but rather to highlight the need for further translational studies involving humans. She noted that occasional use of small amounts as an additive may not be harmful, but daily use as an ingredient and the cumulative effect of the thickener are causes for concern.
Histological analyses of the rats' colon tissues confirmed an increased inflammation score. Biochemical tests revealed significant changes in the intestinal barrier. Specifically, the researchers observed a higher expression of the protein Claudin-2 in the intestinal epithelium. This protein regulates permeability between intestinal cells, and its increased expression indicated a loss of intestinal barrier integrity. Rischiteli explained that xanthan gum is reactive and opens the intestinal barrier by altering Claudin-2, which then triggers an inflammatory cascade.
Additionally, the study found an increase in pro-inflammatory markers, including the cytokines IL-1β and TNF-α. These markers reinforced the inflammatory response. Rischiteli pointed out that TNF-alpha is particularly associated with the death of cells lining the intestine, known as the epithelium, and the development of inflammatory diseases. The consumption of xanthan gum also induced an inflammatory state characterized by an increased presence of defense cells, specifically lymphocytes, in the intestinal wall. This process was more intense in groups of rodents that received medium and high doses of the additive.
While the diversity of gut bacteria, or microbiota, did not change significantly overall, chronic consumption of xanthan gum altered the observed microbial balance. For example, the number of bacteria in the phylum Elusimicrobiota increased. This phylum is associated with inflammatory states. Rischiteli stated that this change indicates a state of dysbiosis, even without major alterations in the dominant bacterial groups.
The study's results help explain a previously observed link between xanthan gum and necrotizing enterocolitis in premature infants. In 2012, 22 newborns in the United States developed intestinal inflammation after consuming formula thickened with the additive. The inflammation led to the death of intestinal tissue in these infants, and at least three of them died. Following these cases, the U.S. Food and Drug Administration FDA banned the use of xanthan gum in premature infants and recommends avoiding its use in infants altogether.
Until this study, the connection between xanthan gum and necrotizing enterocolitis in infants was only a clinical hypothesis or an empirical observation. Claudia Oller, a professor at UNIFESP who coordinated the study, noted that the rat study proved causality, demonstrating that xanthan gum does cause inflammation. The research validated the biological model of the metabolic pathway involved in the inflammatory process in the colon. Oller stated that the process described in the UNIFESP study confirms the hypothesis of American doctors regarding what occurs in the immature intestines of premature infants.
Rischiteli emphasized 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. She reiterated the guidelines from the Dietary Guidelines for the Brazilian Population, which recommend avoiding ultra-processed foods and foods high in additives.
Rischiteli explained that xanthan gum is a biotechnology product derived from a fermentation process involving the bacterium Xanthomonas campestris. She described it as a plant pathogen that, in nature, infects a variety of plants and can be observed when cabbage or kale begin to spoil.
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 Rischiteli. Based on the study results, she recommends monitoring gut health and adopting strategies to protect the gut, such as using probiotics.
The researchers stress that while the study was conducted on rats, the mechanisms identified are likely relevant to human health. They call for more research involving human subjects to better understand the risks associated with chronic xanthan gum consumption. The study was supported by FAPESP and published in PLOS One with the title "Xanthan gum intake modifies the colon microbiota profile and causes mild colon inflammation in rats" by Silva Rischiteli et al., with a DOI of 10.1371/journal.pone.0347232.
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