Gut microbiota-dependent anti-obesity mechanisms of Pu-erh tea polysaccharides: a comparative study of raw and ripened forms

Pu-erh tea, a well-known fermented tea, is classified into raw and ripened types, both associated with weight loss. As key components, raw Pu-erh tea polysaccharides (R-TPS) and ripened Pu-erh tea polysaccharides (F-TPS) are known to regulate blood glucose and lipids, contributing to anti-obesity effects. However, differences in their mechanisms remain unclear, limiting their targeted development. This study characterized their structures and evaluated their effects in high-fat diet-induced obese mice using 16S rRNA sequencing and fecal microbiota transplantation (FMT). Compared to R-TPS, F-TPS contained more galactose, arabinose, rhamnose, and glucose but had a higher molecular weight, while R-TPS was richer in galacturonic acid. Both polysaccharides alleviated weight gain and reshaped gut microbiota. Notably, F-TPS more effectively improved glucose homeostasis, enhanced lipolysis, and reduced inflammation, whereas R-TPS primarily inhibited adipogenesis. Crucially, these differential effects were characterized by distinct gut microbiota-dependent associations: F-TPS enrichment of Muribaculaceae, Lachnospiraceae, and Lactobacillaceae was closely correlated with improved glucose metabolism, lipid metabolism, and inflammation, while R-TPS specifically increased Akkermansiaceae abundance, which correlated with inhibited adipogenesis and utilization of energy. These findings underscore the potential of R-TPS and F-TPS as functional foods for personalized obesity management via gut microbiota modulation.