Researchers from King’s College London have found that molecules in stool samples can accurately reflect what people eat and how their gut microbiome responds, offering a potential new tool to study nutrition and its impact on health.
The study shows that the faecal metabolome – the collection of molecules, or ‘metabolites,’ in stool produced when the gut and its resident microbes break down the food we eat – can capture the complex interactions between diet and gut microbes.
The researchers analysed data from 2,647 participants across two large UK cohorts, TwinsUK and ZOE PREDICT1, integrating data on 650 faecal metabolites, data on gut microbe species, and detailed dietary information from food consumption questionnaires. Using machine-learning approaches, they found that metabolites in stool reflected the intake of 10 different food and beverage groups, including meat, nuts, wholegrains, and tea and coffee, as well as overall adherence to healthy or unhealthy dietary patterns. The study, published in Nature Communications, also identified over 400 associations between specific food groups and metabolites.
Dr Cristina Menni, co-senior author and Senior Lecturer in Molecular Epidemiology at King’s College London and co-senior author of the paper, said: “These findings bring us closer to turning simple stool analyses into powerful tools for understanding how diet and gut microbes interact – helping to design dietary strategies that improve health from the inside out.”