Polysorbate 80 and CMC effects on gut microbiome and barrier
What it found
In a lab model of the human gut, polysorbate 80 and carboxymethylcellulose changed the mix of gut bacteria and, through those changes, affected the gut lining.
The two additives acted differently.
What they found
Animal and lab studies
Bacteria changes with P80
Polysorbate 80 increased Firmicutes and decreased Bacteroidota and Verrucomicrobiota in a dose-dependent way. It also significantly decreased Bacteroides dorei and Akkermansia, which are linked to anti-inflammatory potential.
Bacteria changes with CMC
Carboxymethylcellulose increased Firmicutes and decreased Actinobacteriota in a dose-dependent way. It also increased Ruminococcus torques and Hungatella, which can harm barrier function, and decreased Bifidobacteriaceae and Blautia.
Ammonium production
Ammonium rose in a dose-dependent way in all three colon reactors when polysorbate 80 was added, and in one reactor with carboxymethylcellulose. Higher ammonium was also seen in the other two reactors with carboxymethylcellulose.
Gut lining with P80
The bacteria fed polysorbate 80 did not significantly affect gut lining integrity. But the liquid around them disrupted it less than the additive alone.
Gut lining with CMC
Both the bacteria fed carboxymethylcellulose and the liquid around them reduced gut lining integrity, even though the additive alone did not.
Short-chain fatty acids
No significant differences were found in short-chain fatty acid levels between the additive-fed models and the control.
What the authors conclude
“These findings highlight the need to incorporate the gut microbiome in the risk assessment of these additives.”
Also in their conclusions
- They conclude that both additives altered the microbiome composition in a dose-dependent manner, increasing microbial groups with proinflammatory abilities and decreasing those that reinforce barrier function.
- They state that the addition of both emulsifiers increases ammonium concentration in a dose-dependent manner, which could have a detrimental effect on human health.
- They highlight the need to incorporate the gut microbiome in the risk assessment of food additives.
How it was done
The authors note that these emulsifiers are common in ultra-processed foods and that previous studies raised concerns about their effects on gut bacteria and gut health. They wanted to test whether these effects happen at doses people actually consume and whether they depend on the dose.
They used a four-stage lab model of the human colon, seeded with stool from five healthy children aged 4 to 6. They fed the model increasing doses of polysorbate 80 (1, 3, and 5 grams per litre) or carboxymethylcellulose (0.3, 1, 3, and 5 grams per litre) over several weeks, then measured changes in bacteria and in gut lining integrity using Caco-2 cells.
What it can’t tell you
- This was a lab model using stool from five children, so it cannot show what happens in the human body.
- The study cannot show whether these changes would lead to health problems in people over time.
- The effects on gut lining were tested in cells, not in living animals or people.
Who paid
- Conflicts
- Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
- Authors work at
- Instituto de Investigación en Ciencias de la Alimentación, Spain
The paper
- Title
- Polysorbate 80 and carboxymethylcellulose: A different impact on epithelial integrity when interacting with the microbiome
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Bellanco A, Requena T, Martínez-Cuesta MC (2025). Polysorbate 80 and carboxymethylcellulose: A different impact on epithelial integrity when interacting with the microbiome. Food and chemical toxicology. doi:10.1016/j.fct.2025.115236Free full textPubMed 39778648DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error