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

Pectin, a class of dietary fibers with significant structural diversity, has great potential as tailor-made prebiotics. This study explores the relationship between the structural diversity of 17 chemically and enzymatically modified citrus pectins rich in homogalacturonan, as well as a rhamnogalacturonan-rich apple- and potato pectin extract, and their impact on fecal microbial ecosystems. A single donor screening experiment revealed that linear pectins with a high galacturonic acid content promoted the butyrate producing genera Faecalibacterium and Gemmiger. These findings were confirmed in a 12-donor experiment, where CP3 MOD 2, a highly linear citrus pectin, increased the absolute abundances of both of these genera, while suppressing the opportunistically pathogenic taxa of Eschirichia and the Pseudomonota. Apple and potato pectin elicited less selective responses, mainly through an increase in Bacteroidota, most notably Phocaeicola. Metabolome analysis also demonstrated an increased production of acetate during citrus pectin fermentation. These results identify CP3 MOD 2 as a promising prebiotic candidate due to its potential to favorably shift the gut microbiome composition to a more beneficial configuration, with higher ratios of butyrate-producing to opportunistically pathogenic taxa. A further in vivo exploration of this homogalacturonan rich citrus pectin seems warranted to confirm its potential as a next-generation prebiotic.