Apple Intake Effect on Faecal Metabolome

Overview

This pilot dietary intervention study aimed to investigate whether short-term consumption of apples influences the human faecal metabolomic profile. Apples are a commonly consumed source of dietary fibre, particularly pectin, which undergoes microbial fermentation in the colon and may lead to measurable metabolic changes. Healthy adult volunteers were instructed to consume three apples per day for three consecutive days under free-living conditions. Faecal samples were collected before and after the intervention and analysed using proton nuclear magnetic resonance (¹H NMR) spectroscopy to assess changes in metabolite concentrations. The study sought to explore whether metabolomic profiling can detect functional microbial responses to increased fruit intake and provide preliminary insight into the metabolic impact of short-term dietary fibre exposure.

This study was designed as a single-arm exploratory dietary intervention to evaluate short-term metabolic responses to increased intake of fruit-derived dietary fibre. Participants were instructed to consume three fresh Gala apples per day for three consecutive days while otherwise maintaining their habitual diet and lifestyle. The intervention was conducted under free-living conditions to reflect realistic dietary behaviour. Faecal samples were collected immediately before the intervention and after completion of the three-day exposure period. Samples were processed using standardized laboratory protocols to obtain aqueous extracts suitable for metabolomic analysis. Proton nuclear magnetic resonance (¹H NMR) spectroscopy was employed to generate quantitative metabolic profiles, enabling detection of metabolites associated with microbial fermentation and host-microbe metabolic interactions. Metabolite concentrations were quantified using targeted profiling approaches, and both multivariate and univariate statistical analyses were applied to assess intervention-related changes in the faecal metabolome. The study was intended to provide mechanistic insight into how short-term consumption of a commonly consumed fruit may influence gut microbial metabolic activity, and to evaluate the feasibility of metabolomics-based assessment of dietary exposures in small-scale human intervention studies.