Once a microbiologist, always a microbiologist…..it would be fair to say that I spent most of my degree years analysing poo of some sort. Whether it was from water up and downstream of the local sewage works or investigating the microbiome of our resident waterfowl on the University lakes….and I will spare you the details of what we found when we decided to swab the halls of residence “facilities”.
It makes be shudder just thinking about it, but I’m still alive to tell the tale!
With the enormous wealth of gut microbiome research being published in recent years, I positively relish the opportunity to talk about poo as there are few substances as revealing as the humble stool sample!
The unsung here of early detection
Let’s be honest, talking about poo isn’t everyone’s cup of tea. But when it comes to poo tests that we should all know about, faecal immunochemical testing (FIT) – the bowel cancer screening test – has quietly become the unsung hero of early detection. Since NHS England rolled out FIT screening tests in 2019, millions of tests have been completed and a staggering 23,500 cancers have been detected.
To put that into context, Wembley stadium seats 90,000 people. If you filled the stadium with the next cohort of people usually invited to do a FIT screening test, about 118 cancers would be detected among them. That’s 118 lives potentially saved, simply by sending a poo sample through the post.
Epic!
And this may be about to increase as NHS England has just announced that from February 2026, the FIT threshold is being lowered from 120 to 80 micrograms of blood per gram. This change alone is expected to detect around 600 additional bowel cancers early each year and find 2,000 more people with high risk polyps. That’s an 11% boost in cancer detection simply by adjusting the threshold. It goes to show just how reliable and sensitive FIT is.
Still, as microbiome research booms, could adding a dash of microbial sleuthing supercharge bowel testing?
Poo powered prediction
FIT measures hidden blood in a stool sample — a reliable proxy for cancerous lesions that bleed. The test has always been remarkably sensitive and the recent threshold change is expected to trigger 35% more screening colonoscopies, demonstrating that FIT can reliably detect even minuscule traces of blood that warrant further investigation.
However, bleeding isn’t the only sign of trouble in the bowel. Researchers are investigating whether the unique mix of bacteria in our gut could flag early signs of bowel cancer or precancerous growths, and some pilot studies suggest that combining microbiome data with the existing FIT test may boost screening accuracy.
Microbiome research is also expanding beyond cancer. Inflammatory bowel diseases (IBD), like Crohn’s disease and ulcerative colitis, are often challenging to diagnose early, especially in younger people. Calprotectin testing (another poo test – huzzah!) is widely used to detect inflammation, but it doesn’t always provide a clear answer.
Researchers are now exploring whether microbiome profiles could offer a more detailed picture, helping to distinguish IBD from functional bowel conditions like irritable bowel syndrome (IBS). This could lead to earlier, more accurate diagnoses without the need for invasive tests such as colonoscopies (double huzzah as colonoscopy capacity is an ongoing issue for many health economies).
From the lab to the population: practical questions
Introducing microbiome screening raises logistical and ethical questions. For example, the bowel cancer screening programme in England already operates at a high throughput level in NHS laboratories, processing tens of thousands of samples efficiently every day. Any additional analysis, such as testing for microbiome signatures, would need to fit within this system without adding delays or complexity.
There are also questions about consent and communication. Would patients need to give specific permission for this level of microbial testing? And if microbiome patterns suggest only a raised risk, rather than a diagnosis, how should that be communicated without causing unnecessary anxiety?
Another factor is quality assurance. FIT testing benefits from long established external quality assessment (EQA) schemes and national standards. For microbiome testing to reach similar levels of trust and consistency, laboratories will need harmonised methods and robust benchmarking, something currently lacking in this area.
Why I’m watching this space
At Accelerate, we support scientific innovators in translating complex scientific concepts to real world adoption in clinical and research settings so it’s important that we keep our eyes firming focused on the horizon.
So, I’m going to keep talking about poo and keep reading the research. As understanding of the microbiome progresses, I’ll be watching closely to see how it reshapes thinking around disease prevention, detection and treatment.
Remember, if the eye is the window to the soul, then your poo is the dashboard of your digestive system!
Poo mantras aside, harnessing microbiome knowledge may offer a genuine step change in health screening that could transform a simple poo test into a molecular microscope. And who knows, by talking sh*t occasionally, we might just save more lives.
References
Benton, S. 2025. The evolving English Bowel Cancer Screening Programme. Faec Meet 2025, 5th June 2025, Birmingham, UK.
Fraser CG. Assuring the quality of examinations using faecal immunochemical tests for haemoglobin (FIT). Clin Chem Lab Med. 2020 Oct 20;59(2):245-247. DOI: 10.1515/cclm-2020-1509
Miracle-Huguet, C. 2025. New strategies to improve precision and specificity of FIT test for CRC screening. Faec Meet 2025, 5th June 2025, Birmingham, UK.
Smith, R. 2025. Using combination OC-Sensor Faecal Calprotectin and FIT to diagnose Inflammatory Bowel Disease. Faec Meet 2025, 5th June 2025, Birmingham, UK.
Thomas AM, et al. Metagenomic analysis of colorectal cancer datasets identifies cross-cohort microbial diagnostic signatures and a link with choline degradation. Nat Med. 2019 Apr;25(4):667-678. Doi: 10.1038/s41591-019-0405-7
Wembley Stadium facts https://www.wembleystadium.com/about/stadium-facts-and-features
Wirbel, J., Pyl, P. T., Kartal, E., et al. (2019). Meta-analysis of fecal metagenomes reveals global microbial signatures that are specific for colorectal cancer. Nature Medicine, 25(4), 679–689. https://doi.org/10.1038/s41591-019-0406-6
NHS to detect and prevent thousands more bowel cancers with more sensitive screening, 26th January 2026: https://www.england.nhs.uk/2026/01/nhs-detect-prevent-thousands-more-bowel-cancers-more-sensitive-screening/
Philippa Bevan has over 25 years commercial and public sector experience in marketing, market research and product management spanning the education, laboratory, medical device, technology transfer and packaging industries. Philippa has a BSc (Hons) in Microbiology and Virology and is member of the Chartered Institute of Marketing and an Associate Member of the Market Research Society.
