Analysis of the spatiotemporal digestive characteristics of different forms of pine pollen in elderly populations using an in vitro digestion model system

This study employed the BGR-07 in vitro dynamic digestion model to systematically evaluate the digestive characteristics and probiotic effects of broken-wall pine pollen (PB), whole-wall pine pollen (WPB), and its wall extract (T) within a simulated elderly gastrointestinal environment. The results indicate that cell wall disruption significantly impaired the pollen wall structure, facilitating the release of its contents. Consequently, PB exhibited higher glucose release and enhanced activity of multiple digestive enzymes (such as superoxide dismutase and α-amylase) during the gastrointestinal digestion phase. During the colonic fermentation phase, PB effectively promotes the proliferation of butyrate-producing bacteria (such as Roseburia and Lachnospira ) and drives the production of active intestinal gases (such as H 2 and CO 2 ). WPB exerts minimal disturbance on the microbiota, whereas T demonstrates potential for enhancing both α and β diversity within the microbiota, notably increasing the relative abundance of beneficial bacteria such as Bifidobacterium . Correlation analysis further revealed a close association between intestinal gas composition and microbial community structure. In summary, PB is more suitable for rapid nutritional supplementation and promoting microbial metabolism in the elderly, while WPB and T show potential in maintaining microecological homeostasis and improving long-term microbial diversity respectively. • Investigated the effects of three types of pine pollen on gut microbiota. • Analysed hydrogen-related pathways affecting gut microbiota. • Continuous digestion of the stomach, duodenum, jejunum, ileum, ascending colon. • Discovery of pine pollen's capacity to induce gastrointestinal enzyme activity.