Dietary Polysaccharides for Overweight and Obesity Management: Targeting AMPK via the Gut Microbiota and Metabolites—A Review

Obesity arises from dietary energy intake-expenditure imbalance. 5'-Adenosine monophosphate-activated protein kinase (AMPK), a core regulator of biological energy metabolism, is a key target for obesity research and can be activated by endogenous stimuli, such as cellular stress and physical exercise. As natural active components with diverse sources and biological functions, dietary polysaccharides have shown potential lipid-lowering and antiobesity effects in preclinical studies. This narrative review systematically summarizes their structural characteristics, sources, absorption-utilization mechanisms and structure-activity relationships, focusing on their regulatory effects on obesity via the AMPK pathway. We searched PubMed and Web of Science for publications (2014-2026) using "dietary polysaccharides,""AMPK,""obesity," and "gut microbiota" as key words, screening original studies and reviews relevant to the core topic. Correlative evidence suggests that dietary polysaccharides are associated with altered expression of lipid metabolism-related factors through potential modulation of gut microbiota and its metabolites, with indirect links to AMPK activation. Such AMPK regulatory effects have tissue/organ specificity, and the causal relationship of each link remains to be rigorously established. Notably, the majority of current evidence derives from in vitro and rodent models, and extrapolation to human obesity management requires caution, as high-quality human clinical trials are urgently needed to validate the translational potential of these preclinical findings. This review clarifies the potential mechanism and existing research gaps of dietary polysaccharides in obesity alleviation, providing a scientific basis for the research and development of lipid-lowering functional foods based on dietary polysaccharides.