Tremella fuciformis , commonly known as snow fungus, is a traditional edible and medicinal fungus widely used in Asian countries for centuries. Its main bioactive constituents, Tremella fuciformis polysaccharides (TFPs), have attracted considerable attention in both food and pharmaceutical industries due to their diverse biological activities. TFPs exhibit a broad spectrum of health-promoting effects, including microbial homeostasis, immuno-modulatory, antioxidant, anti-hyperglycemic, anti-hyperlipidemia, and others. This review summarizes recent advances in the extraction, purification, structural characterization, and pharmacological action of TFPs. The findings suggest that TFPs are promising natural bioactive compounds with potential applications in disease prevention and treatment, and they represent valuable candidates for the development of functional foods and therapeutic agents.

This study systematically investigated the dose–response relationship of resistant starch type 2 (RS2; Hi-maize 260; 0–15 g/L) on gut microbial composition, short-chain fatty acid (SCFA)/gas output, and tryptophan catabolism using an in vitro fermentation model. The highest RS2 concentration (15 g/L) elicited optimal metabolic outcomes, including maximal SCFA production; significant H₂S reduction; and redirected tryptophan metabolism from potentially detrimental indoles toward neuroprotective metabolites. Microbial profiling revealed dose-dependent enrichment of saccharolytic taxa (Bifidobacterium, Lactobacillus) with concomitant suppression of proteolytic pathobionts (e.g., Escherichia-Shigella). Correlation analyses revealed strong positive associations between beneficial microbes and both SCFAs and neuroprotective metabolites, whereas pathogenic taxa correlated inversely with these compounds. Collectively, these findings establish that functionally relevant microbiome modulation requires a sufficiently high, dose-tailored intake of RS2, providing a rational basis for precision dietary strategies aimed at improving host metabolic and gut health.

Fu brick tea (FT), known for regulating lipid metabolism, was studied to explore its lipid-lowering mechanism by analyzing its effects on gut microbes and adipose tissue. Mice were given chow, high-fat diet (HFD), or HFD + FT aqueous extract (FTE, 400 mg per kg BW). FTE reduced HFD-induced fat deposition, altered gut microbiota (enriched the “glycerolipid metabolism” pathway, reversed HFD-suppressed Firmicutes_bacterium_ASF500), and affected epididymal fat transcriptome (genes enriched in PPAR, glycerolipid/fatty acid metabolism). Four lipid-related genes (Lipf, Lep, Kdsr, Esrra) showed reversed expression patterns, while FTE treatment demonstrated no significant in vitro effects on adipocyte differentiation. FTE may exert lipid-lowering effects via regulating gut microbe/adipose glycerolipid metabolism, with downstream metabolites playing a key role. In summary, FTE may alleviate lipid deposition by elevating Firmicutes_bacterium_ASF500 to regulate dietary derived metabolites, which may enhance Esrra-mediated fatty acid oxidation-related gene expression, thereby improving triglyceride metabolism. Further studies are warranted to elucidate the specific roles and interactions of FTE's potential microbial and gene targets.