Inulin as a multifunctional prebiotic: from gut modulation to systemic health benefits

Abstract In recent years, plant-based nutrition has attracted great interest worldwide. Inulin is a soluble prebiotic dietary fiber derived from plants that enhances digestive health by modulating the gut microbiota. It is fermented by Bifidobacterium and Lactobacillus species, resulting in the production of short-chain fatty acids, which promote gut barrier integrity, immune equilibrium, metabolic health, and overall systemic wellness. Additionally, it enhances the production of short-chain fatty acids, strengthens gut barrier function, and reduces inflammation. As a prebiotic, it is fermented by colon bacteria. Prebiotics positively influence the gut microbiota due to their ability to be selectively utilized by beneficial bacteria through specific enzymatic activities. Based on this biological relevance, this review summarizes recent evidence on the structural characteristics, functional properties, and health effects of inulin. A comprehensive literature search (2017–2025) was conducted using major electronic databases, such as MEDLINE, the Cochrane Library, CINAHL, ClinicalTrials.gov, Scopus, Google Scholar, and Web of Science, identifying 130 studies investigating its influence on gastrointestinal function, metabolic regulation, inflammation, and chronic disease outcomes. This evidence indicates that inulin supplementation can reduce intestinal inflammation, improve lipid and glucose metabolism, and modulate the gut–brain axis. However, variations in dose, degree of polymerization (DP), host condition, and baseline microbiota composition have contributed to inconsistent or even adverse responses across studies. Overall, inulin represents a multifunctional dietary ingredient with promising clinical potential. To fully utilize its benefits, future research should focus on standardized clinical protocols, DP-specific evaluations, and long-term safety assessments to guide the development of next-generation prebiotic formulations tailored to individual microbiome profiles.