Dietary Fibers from Food By-Products: Mechanisms of Gut Microbiota Modulation and Human Health

The increasing emphasis on sustainable food systems has accelerated efforts to valorize agro-industrial by-products as sources of high-value functional ingredients. Among these, dietary fibers recovered from fruit, vegetable, cereal, and legume processing residues have emerged as promising candidates for promoting both environmental sustainability and human health. While these fibers have traditionally been associated with digestive regularity and laxation, growing evidence demonstrates that their biological effects extend far beyond the gastrointestinal lumen through their capacity to shape gut microbial ecology and metabolism. However, the mechanisms linking fiber fine structure to selective microbial fermentation, metabolite profiles, and downstream health outcomes remain incompletely understood. This Research Topic aims to advance understanding of how dietary fibers derived from food and agro-industrial by-products influence gut microbiota composition, microbial metabolic output, and host physiology. The central scientific question is: How do the structural and physicochemical properties of dietary fibers—including monosaccharide composition, glycosidic linkage patterns, degree of polymerization, solubility, and matrix effects—determine microbial community responses, metabolite production, and subsequent health outcomes? Addressing this question requires integrating food chemistry, microbial ecology, nutritional science, and systems biology to establish structure–function relationships that can guide the development of next-generation functional ingredients. Recent advances in multi-omics technologies, in vitro fermentation and gastrointestinal simulation models, and well-designed human intervention studies have created unprecedented opportunities to investigate the complex interactions between dietary fibers, gut microbial communities, and host physiology. Particular emphasis will be placed on substrate-specific microbial fermentation pathways, production of short-chain fatty acids and other bioactive metabolites, modulation of gut barrier function, mucosal and systemic immune regulation, and cardiometabolic health. Understanding these mechanisms will facilitate the rational development of evidence-based functional foods and nutraceuticals while supporting the transition toward sustainable, circular food systems. This Research Topic welcomes multidisciplinary studies exploring the recovery, characterization, biological mechanisms, and health effects of dietary fibers derived from food processing by-products. Contributions may include, but are not limited to: • Innovative extraction, fractionation, and processing technologies for dietary fiber recovery and modification • Structural and physicochemical characterization of fiber substrates and structure–function relationships • Substrate-specific microbial fermentation dynamics and mechanisms of gut microbiota modulation • Production of microbial metabolites—including short-chain fatty acids, bile acid derivatives, and phenolic catabolites—and their biological effects • In vitro fermentation, ex vivo, animal, and human studies investigating health outcomes • Multi-omics approaches integrating metagenomics, metatranscriptomics, metabolomics, and host responses • Development and validation of functional foods and nutraceutical ingredients • Sustainability, circular bioeconomy, and life-cycle assessment of dietary fiber valorizationPersonalized nutrition approaches considering inter-individual variation in baseline microbiome composition and fermentation capacity in response to dietary fiber interventions Topic editors: Vincenzo Disca, Chiara Ceresa, Pedro Ferreira Santos, Clarisse Nobre Source: https://www.frontiersin.org/research-topics/83471/dietary-fibers-from-food-by-products-mechanisms-of-gut-microbiota-modulation-and-human-health