Dietary Fibres on Gut Fermentation

Inclusion Criteria: * Healthy males and females, aged between 18 and 85 years at the start of the study. * Self-reported regular bowel habits, defined as an average frequency of between 3 and 21 bowel movements per week (Mitsuhashi et al., 2018). This weekly average accounts for normal daily fluctuations while ensuring an overall healthy baseline. * Willing and able to comply with all study protocols, including pre-test dietary restrictions (avoiding highly fermentable foods), a 12-hour overnight fast, and consumption of the prescribed dietary fibre test meals. * Willing to accurately record gastrointestinal symptoms using the Visual Analogue Scale (VAS) and complete the Bristol Stool Scale (BSS) logs over the specified periods. * Able to understand the study procedures and provide written informed consent. Exclusion Criteria: * History or current diagnosis of chronic gastrointestinal diseases or conditions (e.g., Irritable Bowel Syndrome \[IBS\], Inflammatory Bowel Disease \[IBD\], coeliac disease, chronic constipation, or history of major gastrointestinal surgery). * Use of systemic antibiotics, prebiotics, probiotics, or medications known to significantly alter gastrointestinal motility within the 3 months prior to the commencement of, or during the study period. * Known food allergies or severe intolerances to any ingredients present in the test meals (e.g., soluble corn fibre, fructo-oligosaccharides). * Females who are currently pregnant, planning to become pregnant during the study period, or lactating. * Currently following a highly restrictive or extreme diet (e.g., strict ketogenic, extreme high-fibre, or medically prescribed diets) that could significantly confound the baseline gut microbiota or fermentation profile.