Whether you had breakfast this morning or not, your pancreas is working quietly behind the scenes. This vital organ produces the enzymes that help digest your food and the hormones that regulate your metabolism. But when something goes wrong with your pancreas, the consequences can be devastating.
Pancreatic cancer has earned the grim nickname “the silent killer” for good reason. By the time most patients experience symptoms, the disease has often progressed to an advanced stage where treatment options become severely limited. In the UK alone, over 10,700 new cases and 9,500 deaths from pancreatic cancer were recorded between 2017 and 2019, with incidence rates continuing to rise.
The most common form, pancreatic ductal adenocarcinoma (PDAC), develops in the pancreatic duct – a tube connecting the pancreas to the small intestine.
When tumours form here, they can block the flow of digestive enzymes, causing energy metabolism problems that leave patients feeling chronically tired and unwell. Yet these symptoms are often so subtle that they’re easily dismissed or attributed to other causes.
Now, researchers are turning to an unexpected source for early PDAC detection: faecal samples. While analysing poo might seem an unlikely approach to cancer diagnosis, scientists are discovering that our waste contains a treasure trove of information about our health.
This is because your gut is home to trillions of bacteria – in fact, bacterial cells in your body outnumber human cells by roughly 40 trillion to 30 trillion. These microscopic residents form complex communities that can reflect the state of your health, including the presence of disease.
Since PDAC typically develops in the part of the pancreas that connects to the gut, and most people have regular bowel movements, stool samples provide a practical, non-invasive window into what is happening inside the body.
Global evidence builds
This innovative approach has been validated in studies across several countries, including Japan, China and Spain. The latest breakthrough comes from a 2025 international study involving researchers in Finland and Iran, which set out to examine the relationship between gut bacteria and pancreatic cancer onset across different populations.
The researchers collected stool samples and analysed bacterial DNA using a technique called 16S rRNA gene amplicon sequencing. Despite the complex name, the principle is straightforward: scientists sequence and compare a genetic region found in every bacterium’s genome, allowing them to both identify and count different bacterial species simultaneously.
The findings from the Finnish-Iranian study were striking. Patients with PDAC exhibited reduced bacterial diversity in their gut, with certain species either enriched or depleted compared with healthy people. More importantly, the team developed an artificial intelligence model that could accurately distinguish between cancer patients and healthy people based solely on their gut bacterial profiles.