Xanthan gum (E415) and gut inflammation
New scientific data and what it means for manufacturers

Xanthan gum (E415) is one of the most widely used food additives in the world. Produced biotechnologically by fermentation using Xanthomonas campestris bacteria, it gives products their desired texture — from creamy ice cream and stable sauces to gluten-free pasta. For decades it was considered biologically inert: indigestible, safe, with no effect on the body. A new study from the Federal University of São Paulo changes that picture, providing the first experimental evidence that chronic consumption of xanthan gum induces colitis and damages the intestinal barrier.

Background: what is xanthan gum and where will you find it

E415 is an exopolysaccharide — a complex sugar produced by the bacterium Xanthomonas campestris, the same plant pathogen that in nature infects cabbage and kale, causing them to rot. In the industrial process, the bacterium ferments a substrate (usually glucose or sucrose), producing a viscous substance with exceptional rheological properties.

Xanthan gum serves the following functions in food:

• Thickener — provides consistency to sauces, dressings and instant soups
• Emulsion stabiliser — prevents separation in ice cream, beverages and yoghurts
• Gelling agent — replaces gluten in gluten-free baked goods
• Liquid thickener for medical use — facilitates swallowing for people with dysphagia

It is also an ingredient in many protein shakes, liquid food supplements and ultra-processed foods. The global xanthan gum market is estimated to exceed USD 1 billion per year.

The UNIFESP study: what was actually found

The study published in April 2026 in PLOS ONE (Rischiteli et al., DOI: 10.1371/journal.pone.0347232) is a 10-week experiment on rats that received xanthan gum at various doses. Key findings:

• Colitis — histopathological examination revealed higher inflammation scores in animals receiving E415, with the presence of an increased number of lymphocytes in the intestinal wall.
• Increased claudin-2 expression — the protein regulating the permeability of tight junctions between intestinal epithelial cells was overexpressed in all dose groups (confirmed immunohistochemically), indicating an opening of the intestinal barrier. Expression of ZO-1 — another tight junction protein — was also elevated.
• Elevated pro-inflammatory cytokines — IL-1β and TNF-α were significantly higher in rats on a xanthan gum diet. TNF-α is particularly associated with epithelial cell death and the development of inflammatory bowel disease.
• Microbiota dysbiosis — although overall alpha diversity did not decrease significantly, there was a shift in the proportions of bacterial groups, including an increase in Elusimicrobiota — a phylum associated with inflammatory conditions.

The results showed a varied dose–response relationship: inflammation scoring and lymphocyte infiltration increased at medium and high doses, whereas IL-1β peaked at the medium dose (inverted U shape), and quantitative measurement of claudin-2 (ELISA) was significantly elevated mainly at the lowest dose. The authors emphasise that the aim is not to demonise the substance, but to signal the need for translational studies in humans.

Mechanism: how xanthan gum damages the intestinal barrier

The intestinal barrier is a single layer of epithelial cells (enterocytes) connected by tight protein junctions (tight junctions). The claudin protein family plays a key role. Claudin-2 forms permeability channels — its overexpression means the barrier becomes "leaky" (a phenomenon referred to as leaky gut).

According to the study authors, the mechanism is as follows:

1. Xanthan gum interacts with the intestinal epithelium
2. Claudin-2 is overexpressed in tight junctions
3. The intestinal barrier loses integrity — permeability increases
4. Antigens and bacterial fragments penetrate into the submucosal tissue
5. Lymphocyte recruitment and activation of the inflammatory response
6. Increased production of pro-inflammatory cytokines (IL-1β, TNF-α)
7. TNF-α induces enterocyte apoptosis — further barrier damage

This self-perpetuating cycle explains why the effects accumulate over time and at higher doses.

flowchart TD
    A[Chronic consumption of\nxanthan gum E415] --> B[Interaction with colonic\nintestinal epithelium]
    B --> C[Claudin-2 overexpression\nin tight junctions]
    C --> D[Loss of intestinal\nbarrier integrity]
    D --> E[Penetration of antigens\nand bacterial fragments]
    E --> F[Lymphocyte recruitment\nto the intestinal wall]
    F --> G[Increase in IL-1β and TNF-α]
    G --> H[TNF-α induces enterocyte\napoptosis]
    H --> D
    G --> I[Moderate colitis]
    style A fill:#1e3a5f,stroke:#38bdf8,color:#e2e8f0
    style D fill:#7f1d1d,stroke:#f87171,color:#fecaca
    style I fill:#7f1d1d,stroke:#f87171,color:#fecaca
    style H fill:#92400e,stroke:#f59e0b,color:#fef3c7

Historical context: premature infants, SimplyThick and NEC

The new study did not emerge in a vacuum. As early as 2012, Beal et al. described in The Journal of Pediatrics a series of 22 cases of necrotising enterocolitis (NEC) in premature infants in the USA. The common denominator was the administration of formula thickened with SimplyThick, whose main thickening ingredient is xanthan gum.

At least 3 neonates died. NEC is a severe condition involving necrosis of intestinal tissue — potentially fatal in immunologically immature premature infants. The FDA issued a warning and prohibited the use of xanthan gum-based thickeners in premature infants.

Until now, the link between E415 and NEC was merely a clinical hypothesis — an empirical observation without an explained mechanism. The Brazilian study provides that missing link: opening of the intestinal barrier via claudin-2 → inflammatory cascade → tissue damage. In the immature intestine of a premature infant, this mechanism may have led to full-blown NEC.

Xanthan gum and the microbiota: not as inert as previously thought

For years the dogma was: xanthan gum is not digested by the human body and passes through the gastrointestinal tract unchanged. A study by Ostrowski et al. published in 2022 in Nature Microbiology overturned this concept.

It turns out that gut bacteria — in particular a species from the Ruminococcaceae family — have developed the ability to degrade xanthan gum. The breakdown products (oligosaccharides) are subsequently fermented by Bacteroides intestinalis into short-chain fatty acids (SCFAs). In other words: xanthan gum is not biologically inert — it influences the composition and metabolism of the microbiome.

The 2026 Brazilian study completes this picture: chronic administration of E415 increased the proportion of bacteria from the phylum Elusimicrobiota, associated with inflammatory conditions. This increase occurred without a dramatic change in overall alpha diversity — indicating a subtle but potentially clinically significant dysbiosis.

These two findings together create a coherent picture: xanthan gum is metabolised by the microbiota, alters its composition, and the products of that metabolism — or the direct interaction with the epithelium — may trigger an inflammatory response.

flowchart LR
    subgraph OLD["OLD PARADIGM"]
        direction TB
        D1[Xanthan gum E415]
        D2[Not digested]
        D3[Passes through the gut\nunchanged]
        D4[Biologically inert]
        D1 --> D2 --> D3 --> D4
    end
    subgraph NEW["CURRENT STATE OF KNOWLEDGE 2022-2026"]
        direction TB
        N1[Xanthan gum E415]
        N2[Degraded by\nRuminococcaceae]
        N3[Oligosaccharides fermented\nby B. intestinalis → SCFAs]
        N4[Shift in microbiota composition\nincrease in Elusimicrobiota]
        N5[Interaction with epithelium\nclaudin-2 overexpression]
        N6[Colitis]
        N1 --> N2 --> N3
        N1 --> N4
        N1 --> N5 --> N6
    end
    OLD -.->|Overturned by\nresearch 2022-2026| NEW
    style D4 fill:#064e3b,stroke:#10b981,color:#d1fae5
    style N6 fill:#7f1d1d,stroke:#f87171,color:#fecaca

Regulatory status of E415 in the EU: what the law says today

Xanthan gum is an authorised food additive in the EU under Regulation (EC) No 1333/2008. Key regulatory facts:

• EFSA 2017 (EFSA Journal 2017;15(7):4909) — re-evaluation of E415. The ANS Panel did not establish an ADI (acceptable daily intake), concluding that the additive is safe at the levels used. No genotoxicity or carcinogenicity was identified.
• EFSA 2023 (EFSA Journal 2023;21(5):7951) — additional safety assessment of E415 in food for infants below 16 weeks of age. The FAF Panel raised no safety concerns for use in food category 13.1.
• No established ADI — paradoxically, not because it is dangerous, but because at the time of assessment no adverse effects were identified even at the highest tested doses.
• Permitted quantum — quantum satis for most food categories (no quantitative limits beyond good manufacturing practice).

Crucially: the 2017 EFSA re-evaluation did not take into account the UNIFESP study (published only in 2026) or the Nature Microbiology discovery (2022) regarding the metabolism of E415 by the microbiota. The state of knowledge on which the safety assessment was based is therefore incomplete in light of the most recent data.

Implications for food and supplement manufacturers

Although a single rat study does not change the law, it changes the risk landscape. Here are the practical implications:

1. Ultra-processed food manufacturers

E415 is present in many products simultaneously (sauce + ice cream + yoghurt + supplement). The cumulative daily intake for a typical consumer of highly processed food may exceed the doses tested in safety studies. It is worth conducting an internal audit of E415 content across the product range and considering reduction where alternatives (e.g. modified starch, guar gum) are technically feasible.

2. Food supplement manufacturers

E415 is sometimes used as an excipient in liquid and gel supplement formats. For supplements intended for daily, long-term use (probiotics, vitamins, omega-3s) it is worth considering a reformulation — particularly since the mechanism in question (loosening of the intestinal barrier) is in direct contradiction with the declared purpose of probiotics.

3. Manufacturers of food for infants and people with dysphagia

These are the most vulnerable populations. Infants have an immature intestinal barrier; people with dysphagia consume thickeners daily. The study authors recommend monitoring the gut health of patients using thickeners and considering protective strategies (e.g. probiotics).

4. Research and development and quality control departments

Documentation justifying the use of E415 should incorporate the latest scientific data as part of a risk assessment (due diligence). In the event of an inspection or a potential EFSA re-evaluation, a manufacturer with an up-to-date risk analysis is in a better position than one relying solely on the 2017 opinion.

flowchart TD
    A[New scientific data\non E415 - UNIFESP study 2026] --> B{What type of manufacturer?}
    B -->|Ultra-processed food| C[Audit of cumulative E415\nacross product range]
    B -->|Food supplements| D[Analysis: is E415\nessential in the formulation?]
    B -->|Food for infants\nand people with dysphagia| E[Highest priority:\nconsider alternatives]
    C --> F[Reduction where\nalternatives are feasible]
    D --> G[Especially probiotics:\nmechanistic contradiction]
    E --> H[Monitor gut health\n+ protective strategies]
    F --> I[Update risk assessment\ndocumentation]
    G --> I
    H --> I
    I --> J[Readiness for potential\nEFSA re-evaluation]
    style E fill:#7f1d1d,stroke:#f87171,color:#fecaca
    style J fill:#1e3a5f,stroke:#38bdf8,color:#e2e8f0

What the study does NOT prove — and why that matters

A rigorous analysis requires identifying the limitations:

• Animal model ≠ humans. The rat intestine differs from the human intestine in terms of length, microbiota and metabolism. Extrapolation requires caution.
• Doses may not reflect real-world intake. The study used controlled doses; human consumption is more variable and generally lower.
• No data on occasional consumption. The authors themselves emphasise that occasional consumption in small amounts is unlikely to cause harm. The concern relates to daily exposure.
• One study is not a consensus. Replication, studies in other models and — above all — studies in humans are needed.

However: this study is not isolated. It fits into a broader picture created by the discovery of E415 metabolism by the microbiota (2022), the earlier NEC cases (2012), and studies demonstrating the effect of hydrocolloids on gut microbiota composition, including an increase in Ruminococcus gnavus (Zhang et al., 2023). The scientific signal is growing.

The Brazilian Dietary Guidelines recommendation — systemic context

The study authors refer to Brazilian dietary guidelines, which recommend avoiding ultra-processed food and products with a high number of additives. This approach is consistent with WHO nutritional policy and the regulatory trend in the EU (the Farm to Fork strategy, Nutri-Score, restrictions on the use of additives in food for children).

In the EU context: Regulation 1333/2008 requires that the use of additives be technologically justified and not mislead the consumer. If translational studies confirm inflammatory effects in humans, the argument of "technological necessity" will need to be weighed against the argument of public health protection.

What next? Regulatory scenarios

Based on an analysis of EFSA procedures and precedents (e.g. titanium dioxide E171, carrageenan E407), the following probable scenarios can be outlined:

1. Scenario 1 (most likely in the short term): No immediate regulatory changes. A single rat study is insufficient to trigger the Article 32 procedure. EFSA awaits replication and human data.
2. Scenario 2 (medium term, 2–4 years): The European Commission requests EFSA to re-evaluate E415 taking into account the new data. Possible establishment of an ADI or restrictions in specific populations (infants, people with IBD).
3. Scenario 3 (unlikely): Withdrawal of authorisation. This would require multiple, consistent evidence in humans — the E171 analogy took over a decade.

Conclusions

Xanthan gum is not a poison. It is a legal, widely used food additive with proven technological properties. But new scientific data from 2022 and 2026 fundamentally changes our understanding of its interactions with the body:

• It is not biologically inert — it is metabolised by the gut microbiota
• Upon chronic consumption it may open the intestinal barrier through claudin-2 overexpression
• It triggers an inflammatory cascade involving TNF-α and IL-1β (at least in rats)
• The historical NEC cases in premature infants now have a mechanistic explanation

For food manufacturers this is not a cause for panic, but a reason for proactive action: updating risk assessments, considering alternatives in products for vulnerable populations and preparing for a potential regulatory re-evaluation. A manufacturer who acts ahead of time will be better prepared than one caught off guard by a change in the rules.

Disclaimer: Tomasz Krawczyk — author of content on EU and Polish food law and food supplements. supplemental.pl · foodlaw.ai. This material is for general information purposes only and reflects the position as of July 2026; it does not constitute legal advice in any individual matter.