Giant bacteria could be living in your gut - but nobody has seen them
DNA from Epulopiscium - one of the largest known bacteria, up to 600 micrometres long - has been found in human gut microbiome samples around the world, a new bioRxiv preprint reports.
- Claim
- GIANT BACTERIA IN YOUR GUT?
- Catch
- DNA ONLY
- Verdict
- A CLUE, NOT PROOF
Researchers at the Technical University of Berlin analysed more than 600,000 microbiome sequences from over 80 countries. Epulopiscium DNA turned up in thousands of human samples, usually making up 1 to 2 per cent of sequences, and in rare cases up to 20 per cent. It was most abundant during the first year of life, and more common in people with inflammatory bowel disease and colorectal cancer.
The catch? This is DNA evidence only. Nobody has yet seen giant bacteria in a human gut under a microscope. An independent expert says the sequences could belong to a different, smaller microbe. The paper is a preprint and has not been peer reviewed. The researchers also think the bacteria may thrive in guts that are already out of balance, rather than causing disease.
SOURCES
- Lyu, Y. et al. (2026). Giant bacteria in gut microbiomes. bioRxiv. DOI: 10.64898/2026.09.30.750856
- Marchant, J. (2026, October 14). Giant bacteria could be living in your gut. New Scientist.
- Sannino, D. R. et al. (2023). The exceptional form and function of the giant bacterium Ca. Epulopiscium viviparus. PNAS. DOI: 10.1073/pnas.2306160120
This video is for general information only and is not medical advice. Talk to a doctor if you have concerns about gut symptoms.
For information only, not medical advice. Talk to a qualified health professional before changing your diet, supplements or treatment.
