Quantification of prebiotic content in Italian foods and estimation of prebiotic intake in a colorectal cancer case-control study

Prebiotics are dietary components that resist digestion and absorption in the gastrointestinal tract. These nondigestible compounds, which can be found in vegetables, fruits, pulses, and other plant-based foods, influence the composition and activity of the gut microbiota. Growing evidence suggests that selected prebiotics may provide various health benefits, including a potential reduction in colorectal cancer (CRC) risk. Estimating prebiotic intake is currently challenging due to the lack of consistent, publicly accessible databases that provide reliable data on their content in various foods. The aim of this study was to determine the prebiotic content, in terms of fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS), of foods consumed in the Italian diet and make the data available in a comprehensive database for nutritional epidemiological research. In a certified laboratory, a range of representative foods were analyzed, including those listed in a validated and reproducible food frequency questionnaire (FFQ) used in case-control studies. We conducted analyses on 35 foods, including 5 fresh and dried fruit items, 15 legumes products, of which 9 soy-based products, and 15 cereal products. The prebiotic content of these foods was determined using alkaline hydrolysis and High-Performance Anion-Exchange Chromatography with Pulsed Amperometric Detection (HPAEC-PAD). On the basis of these data, we estimated the prebiotic intake in a healthy population (n = 100) from a CRC case-control study conducted in Milan, Italy. GOSs were mainly detected in legumes product, and soy-textured proteins were the richest foods (4.81g/100g). FOSs were found in fruits and cereal products and were more abundant in rye whole grain flour (0.77g/100g). In our population, the mean daily intake of prebiotics was 0.244 g for FOSs and 0.362 g for GOSs. These data will serve as a valuable resource for epidemiological studies investigating the relationship between dietary factors and various health outcomes, including the potential impact of prebiotics on CRC risk.