Polysaccharides as emerging functional food components for mood regulation: advances, mechanisms, and future perspectives.

Polysaccharides, widely distributed in plants, fungi, algae, and bacteria, have garnered increasing attention as promising natural agents for mood regulation due to their diverse chemical structures, bioactivities, and safety profiles. Mood disorders, including depression and anxiety, remain major global health challenges with limited treatment options, prompting interest in polysaccharide-based dietary interventions. This review consolidates current findings from in vitro, in vivo, and clinical research on polysaccharides' potential to modulate neuroimmune responses, influence the gut microbiota-brain axis, regulate neurotransmitter synthesis, attenuate oxidative stress, and alter metabolic pathways relevant to mood regulation. Notably, polysaccharides derived from Lycium barbarum and Astragalus exhibit antidepressant and anxiolytic effects in experimental and clinical contexts. Despite promising outcomes, variability in polysaccharide composition, intervention protocols, and assessment methods constrains definitive conclusions. To fully realize the neuropsychological benefits of polysaccharides within mental health nutrition, rigorous large-scale clinical trials and detailed structure-function analyses are imperative. These efforts will advance polysaccharides as viable functional food components for managing mood disorders.