What if a test you already take for one reason could also reveal something important about your gut health? Scientists explored whether leftover samples from a common colon cancer screening test—the Faecal Immunochemical Test (FIT)—could be used to study the community of bacteria in our intestines, known as the gut microbiome.
They looked at samples from 16 healthy volunteers and 100 leftover samples from patients who had taken the test because they had symptoms like rectal bleeding. The key finding was that the bacterial picture from these small, leftover samples remained stable for up to 14 days and was very similar to results from larger, standard stool samples. At least 75 out of the 100 leftover patient samples also had enough DNA to run the analysis.
This is a lab study focused on validating a method. It shows the leftover samples could be a practical and low-cost resource for large-scale research into the gut microbiome. However, it's a first step. The study did not look at whether the information from these samples can tell us anything about a person's health, predict disease, or guide treatment. It simply shows the method is technically feasible and stable over time.