Modified homogalacturonan-rich citrus pectin as potential next-generation prebiotics

Pectin, a structurally diverse class of dietary fibres, holds promise as a next-generation prebiotic. This study evaluated the microbiota-modulating potential of 17 chemically and enzymatically modified citrus pectin fractions, along with rhamnogalacturonan-rich apple and potato pectin extracts, using in vitro batch fermentations inoculated with human faecal samples. A highly linear, homogalacturonan-rich citrus pectin (CP3 MOD 2) selectively increased the absolute abundances of Faecalibacterium and Gemmiger - key butyrate-producing genera - while suppressing opportunistic pathogens such as Escherichia. These effects were confirmed across twelve donors and associated with increased acetate production. Pectin structural features, including high galacturonic acid content and low branching, were positively correlated with beneficial microbial shifts. In contrast, rhamnogalacturonan-rich pectins exhibited broader, less selective responses. The microbiota's baseline composition significantly influenced fermentation outcomes, underscoring interindividual variability. CP3 MOD 2 emerges as a promising candidate for further in vivo evaluation in a targeted, structure-guided prebiotic intervention.