Study · Scientific reports · 2025Conflicts declared

Aspartame, gut bacteria and brain tumours in mice

What it found

In mice with brain tumours, an aspartame diet did not change tumour growth but did change the mix of gut bacteria and the activity of some genes in the tumours.

What they found

Animal and lab studies

Tumour growth

The aspartame diet did not significantly affect tumour growth in the mice.

Gut bacteria change

The aspartame diet changed the mix of gut bacteria. In particular, the relative abundance of the Rikenellaceae family decreased.

Gene activity

In the tumours of mice given aspartame, 6,146 mRNAs were differentially expressed compared with control mice. Of these, 2,730 were upregulated and 3,416 were downregulated.

RNA methylation

The aspartame diet led to 6,322 transcripts with differential m6A methylation, including 2,928 with increased methylation and 3,394 with decreased methylation.

Studies in people and animals

Key genes affected

The m6A peaks and expression levels of MYC, CDKN1A and TGFB1 were greater in the aspartame group. In human GBM data, only TGFB1 expression was linked to worse clinical outcomes.

What the authors conclude

“In conclusion, while aspartame intake did not significantly influence tumor growth, it did alter the composition of gut microbiota.”
Meng K, Bao Y, Chen G, et al, 2025

Also in their conclusions

  • They conclude that while aspartame intake did not significantly influence tumour growth, it did alter the composition of gut microbiota.
  • They state that key m6A-regulated genes were significantly upregulated in GBM tumours exposed to aspartame, and that TGFB1 highlights a potential role in GBM progression mediated by aspartame-induced m6A modifications.
  • They say their findings provide critical evidence for evaluating the safety of artificial sweeteners and open new avenues for GBM treatment strategies.

How it was done

The authors wanted to test whether aspartame intake changes gut bacteria, which might then affect gene activity and tumour progression. They note that it was still unclear whether aspartame affects gene expression and epigenetic regulation during tumour growth.

They gave ten mice with implanted brain tumours either drinking water with aspartame at 50 mg/kg or normal water for 15 days. They then compared the gut bacteria, gene expression and a chemical mark on RNA called m6A between the two groups.

What it can’t tell you

  • This study was in mice with implanted brain tumours, so it cannot show what happens in people.
  • The number of mice was small, and the authors note that they did not look at aspartame metabolites or the tumour microbiome.
  • The link between TGFB1 and clinical outcomes comes from human database analysis, not from the mouse experiment itself.

The paper

Title
Metagenomics and transcriptomics analysis of aspartame's impact on gut microbiota and glioblastoma progression in a mouse model
Type
Study
Evidence
Studies in people · animals · lab
Summarised from
Full text
Cite
Meng K, Bao Y, Chen G, et al (2025). Metagenomics and transcriptomics analysis of aspartame's impact on gut microbiota and glioblastoma progression in a mouse model. Scientific reports. doi:10.1038/s41598-025-06193-5Free full textPubMed 40604039DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error