Research advances in extraction, purification, structural characterization, bioactivities, and gut microbiota...

Codonopsis pilosula (CP), a traditional medicinal and edible plant, is recognized as a significant source of bioactive compounds, with its polysaccharides (CPs) being one of the key active constituents. Research on CPs over the past five years, particularly regarding extraction technologies, structural characterization, pharmacological activities, and mechanisms of action, has not yet been systematically summarized. The review comprehensively consolidates the latest advances in the field, with a focus on innovations in green and efficient preparation techniques, such as ultrasound-assisted extraction and aqueous two-phase extraction. It elucidates the structure-activity relationships between key structural features of CPs, including molecular weight, monosaccharide composition, and glycosidic bond types, and their corresponding biological activities. Moreover, the review summarizes the multifaceted pharmacological effects of CPs, including immunomodulatory, antitumor, antioxidant, neuroprotective, and organ-protective properties. Of particular note, the work thoroughly discusses the microecological mechanisms by which CPs ameliorate metabolic and inflammatory diseases through regulation of the gut microbiota-immunity axis, highlighting their potential to restore intestinal microecological balance by promoting the growth of beneficial bacteria and inhibiting the proliferation of pathogenic bacteria, a perspective rarely highlighted in previous reviews. The review aims to provide a theoretical basis for the full utilization of CPs in functional foods and pharmaceutical development and offers forward-looking perspectives on future research directions.