Xinwei Tian

Tryptophan (Trp) is essential for homeostasis, but direct intake may cause risks. This study compared metabolic kinetics between free Trp and protein-bound Trp from soy protein isolate (SPI) and sheep whey protein (SWP). A novel UPLC-TQ/MS assay was built to quantify Trp and its metabolites simultaneously: 5-hydroxytryptophan (5-HTP), kynurenic acid (Kyna), indole-3-acetic acid (IAA), and indole-3-propionic acid (IPA). Pharmacokinetic profiling showed free Trp peaked rapidly in rats. Tissue distribution exhibited distinct enrichment: Trp in heart and adipose, 5-HTP in kidney and epididymal fat, Kyna in kidney and brown fat, and IAA/IPA in brain. Relative to free Trp, SPI and SWP delayed metabolite release and boosted microbial Trp conversion to IAA and IPA. SPI activated the 5-hydroxytryptamine pathway, raising plasma 5-HTP and fecal IAA; SWP favored the kynurenine pathway, elevating plasma Kyna and fecal IPA. These findings highlight differential outcomes of free versus protein-bound Trp supplementation.

This study aims to explore the underlying mechanism by which theabrownin extracted from Fu brick tea (FBTB) alleviates obesity induced by a high-fat diet (HFD) in mice. Results showed that FBTB intervention ameliorated metabolic disorders, suppressed jejunal lipid accumulation, and enhanced fecal lipid excretion. 16S rRNA gene sequencing demonstrated that FBTB reversed gut microbiota dysbiosis and increased the abundance of potentially beneficial genera such as Dubosiella and Lactobacillus. Metabolomics revealed that FBTB altered tryptophan metabolism and significantly increased cecal levels of indole-3-acetic acid (IAA) and indole-3-propionic acid (IPA). Furthermore, these metabolites activated jejunal aryl hydrocarbon receptor (AhR) and interleukin-22 (IL-22) signaling, subsequently downregulating lipid transporters FATP4 and CD36 to reduce jejunal lipid accumulation. Notably, antibiotic treatment significantly blunted the suppressive effect of FBTB on jejunal lipid accumulation. Overall, FBTB prevents obesity may be through modulating the gut microbiota-tryptophan-IL-22 axis to reduce intestinal lipid accumulation.

Fu brick tea (FBT) combats obesity by modulating gut microbiota, while tryptophan (Trp) lacks direct effects but exerts anti-obesity potential via microbiota-derived metabolites. However, their synergistic anti-obesity effect remains unclear. We demonstrated that low-dose FBT extract (FTE) combined with free Trp or Trp-bound proteins from soy protein isolate and sheep whey protein produced synergistic antiobesity effects in high-fat diet-induced mice. Trp+FTE effectively combated obesity, reducing weight and fat, while alleviating inflammation and hepatocellular steatosis. Further mechanistic analyses showed that Trp+FTE alleviated obesity by tissue-specific regulation of aryl hydrocarbon receptor (AhR) signaling, modulation of Trp metabolic pathways, reshaping gut microbiota composition, and increasing short-chain fatty acid production. Metabolomic profiling further revealed coordinated alterations in amino acid and lipid metabolism, accompanied by elevated levels of beneficial Trp-derived metabolites in peripheral tissues. Collectively, these findings suggest that the synergistic effects are driven by coordinated regulation of AhR-mediated Trp metabolism and gut microbiota modulation.

This study elucidates the antiobesity mechanism of the Fu brick tea extract-millet complex (FTE-M). FTE-M exhibited a dense and smooth microstructure, resulting in improved digestive properties compared with millet alone, including a reduced glycemic index and increased slowly digestible starch and resistant starch contents. In a 10-week high-fat diet mouse model, dietary supplementation with FTE-M inhibited small intestinal α-amylase activity, delayed starch digestion, and improved glucose and lipid metabolism while alleviating inflammation. FTE-M also modulated gut microbiota composition, normalized bile acid profiles, and enriched short-chain fatty acids (SCFAs)-producing bacteria, including Akkermansia, leading to a 2.49-fold increase in total SCFAs. Mechanistically, elevated SCFAs were associated with the activation of free fatty acid receptor 2 (Ffar2) and increased expression of glucagon (Gcg) and peptide YY (Pyy), contributing to enhanced satiety. These findings highlight the potential of combining traditional millet with bioactive components to enhance metabolic functionality, providing a theoretical basis for developing starch-based antiobesity foods.

Selenium, a trace nutrient with nutritional and nutraceutical functions, is limited by a narrow optimal intake range. Selenium nanoparticles (SeNPs) show lower toxicity and higher bioavailability than organic/inorganic selenium, becoming a promising alternative. This review overviews SeNPs, including chemical, physical and green synthesis methods and their effects on properties and functionalities. We then focus on applications of SeNPs: in food/feed (nutritional fortification, enhanced absorption, antibacterial activity, heavy metal detoxification, packaging), and agriculture (fertilizers, plant disease control, mitigating biotic/abiotic stresses). We also consider their safety and efficacy, which are influenced by physicochemical features like particle size and surface property. Finally, knowledge gaps and future directions are highlighted, emphasizing SeNPs potential in food nutrition and sustainable agriculture to boost plant performance and human health.

Amyloid formation, once primarily associated with neurodegenerative diseases, has recently emerged as a versatile platform in materials science and biotechnology. In particular, amyloid-like aggregation triggered by reductive cleavage of disulfide bonds enables the formation of phase-transitioned protein (PTP) nanofilm at interfaces. The resulting nanofilm combines facile fabrication, robust adhesion, flexibility, and tunable functionalities, making it attractive as a sustainable, biobased material, with unique potential in food and agricultural applications where reviews remain lacking. This review outlines current knowledge of PTP nanofilms, focusing on molecular and physicochemical mechanisms underlying their aggregation, as well as key characterization and modulation strategies. Emphasis is placed on interfacial phenomena such as adsorption and tension regulation that govern nanofilm retention and stability. Emerging applications in food preservation and agriculture are highlighted, demonstrating the potential of PTP nanofilm to enhance sustainability and productivity. Future challenges and opportunities are briefly discussed to guide further development of PTP-based systems.

Food safety remains a global concern, with hazardous substances potentially occurring throughout the entire food supply chain, from farm to table. Therefore, rapid and reliable detection methods are critical for food safety monitoring. Small Molecular Organic Fluorescent Probes (SMOFPs) have emerged as powerful tools for detecting food contaminants due to their high sensitivity, selectivity, rapid response, ease of operation, and low cost. This review provides a comprehensive overview of recent advances in SMOFPs for food safety applications, covering fundamental design principles and sensing mechanisms. It summarizes selected publications from 2015 to 2025 on the detection of harmful ions, food additives, foodborne pathogens, and pesticide or veterinary drug residues. In addition, the integration of SMOFPs with advanced smart devices for real-time monitoring is highlighted. This review aims to provide valuable insights and practical guidance to bridge the gap between laboratory research and real-world applications, contributing to improved food quality and public health.