In recent years, the incidence of chronic inflammatory bowel disease (IBD) has been increasing, posing a serious threat to human health. Medication can lead to off-target, systemic side effects and serious complications, and safer treatments are urgently needed. Selenium (Se) supplementation can alleviate IBD by modulating gut flora and increasing antioxidant enzyme activities. Glutathione peroxidase (GPx) is a selenoprotein with good antioxidant capacity to eliminate inflammation and protect the intestinal. Herein, this paper comprehensively reviews the recent research progresses of Se-containing GPxs (GPx1-4) in alleviating IBD with oxidation stress as the main thread, summaries the underlying mechanisms of Se-containing GPx on the regulation of IBD. The different effects of inorganic Se, organic Se, and Se nanoparticles in the treatment of IBD are discussed. 

Hyperuricemia (HUA) is characterized by elevated levels of uric acid (UA) in the bloodstream, resulting from either excessive production or insufficient excretion of UA within the body. If left untreated, progressive or persistent HUA can lead to gout, causing significant harm to human health. Lactic acid bacteria (LAB), generally recognized as safe (GRAS) probiotics, have been shown to alleviate symptoms associated with gastrointestinal disorders such as irritable bowel syndrome and inflammatory bowel disease while supporting overall bodily functions and health. Recently, LAB has emerged as a potentially safe, cost-effective and efficient treatment for HUA. This comprehensive review aims to explore the current literature on the mechanisms through which LAB controls HUA. These mechanisms include suppressing purine metabolism, absorbing purine compounds, modulating microbiota to maintain host global purine homeostasis, reducing intestinal permeability, producing metabolites that alleviate HUA symptoms, promoting the expression of urate excretory proteins and inhibiting the expression of urate reabsorption proteins. The findings presented in this review provide a framework for further investigation into how probiotic LAB can alleviate HUA by influencing UA metabolism and elucidating their underlying action mechanisms.

The traditional nutritional and medical hemp (Cannabis sativa L.) seed protein were explored for the discovery and directional preparation of new xanthine oxidase inhibitory (XOI) peptides by structure-based virtual screening, compound synthesis, in vitro bioassay and proteolysis. Six subtypes of hemp seed edestin and albumin were in silico hydrolyzed by 29 proteases, and 192 encrypted bioactive peptides were screened out. Six peptides showed to be XOI peptides, of which four (about 67%) were released by elastase hydrolysis. The peptide DDNPRRFY displayed the highest XOI activity (IC₅₀ = (2.10 ± 0.06) mg/mL), acting as a mixed inhibitor. The pancreatic elastase directionally prepared XOI hemp seed protein hydrolysates, from which 6 high-abundance XOI peptides encrypted 3 virtually-screened ones including the DDNPRRFY. The novel outstanding hemp seed protein-derived XOI peptides and their virtual screening and directed preparation methods provide a promising and applicable approach to conveniently and efficiently explore food-derived bioactive peptides.

Trehalose is an autophagy-promoting disaccharide, which can improve and delay chronic diseases like neurodegenerative diseases and atherosclerosis, but its bioavailability is severely restricted by endogenous trehalase in mammals. Trehalase inhibitor is a promising and effective way to enhance trehalose bioavailability by preventing trehalose from hydrolyzing. However, previously reported trehalase inhibitors still face safety of long-term use and promiscuous inhibition on intestinal glycosidases. This study carried out a high-throughput virtual screening through molecular pool-based molecular docking combined with in vitro inhibition experiments to screen trehalase inhibitors naturally derived from foods. Out of 1769 small molecules, which include 115 analogs of trehalose, natural monosaccharides, disaccharides, trisaccharides, imidazoles and their derivatives, as well as 20 natural amino acids and their 400 dipeptides, isomaltose, α-isomaltulose, and isomaltitol exhibited the best inhibitory activities, beyond as traditional sweetener and prebiotic. Best of all, isomaltose showed the IC50 and K_i values on trehalase of 5.59 mmol/L and (2.1760 ± 0.3431) mmol/L, respectively. Moreover, isomaltose was resistant to the simulated digestive environment and did not affect intestinal glycosidases includingsuch α-glucosidase, and glucoamylase, making it a reliable edible candidate for a trehalase inhibitor. This study provides new insights into the virtual screening-based identification of new food-derived trehalase inhibitors for enhanced integrity and bioavailability of orally administered trehalose, especially repurposing a prebiotic for another new use as trehalase inhibitor.

Hyperuricemia (HUA) is characterized by elevated levels of uric acid (UA) in the bloodstream, resulting from either excessive production or insufficient excretion of UA within the body. If left untreated, progressive or persistent HUA can lead to gout, causing significant harm to human health. Lactic acid bacteria (LAB), generally recognized as safe (GRAS) probiotics, have been shown to alleviate symptoms associated with gastrointestinal disorders such as irritable bowel syndrome and inflammatory bowel disease while supporting overall bodily functions and health. Recently, LAB has emerged as a potentially safe, cost-effective and efficient treatment for HUA. This comprehensive review aims to explore the current literature on the mechanisms through which LAB controls HUA. These mechanisms include suppressing purine metabolism, absorbing purine compounds, modulating microbiota to maintain host global purine homeostasis, reducing intestinal permeability, producing metabolites that alleviate HUA symptoms, promoting the expression of urate excretory proteins and inhibiting the expression of urate reabsorption proteins. The findings presented in this review provide a framework for further investigation into how probiotic LAB can alleviate HUA by influencing UA metabolism and elucidating their underlying action mechanisms.

This study investigated the combinatorial expression of xanthine dehydrogenase (XDH) and chaperone XdhC from Acinetobacter baumannii and Rhodobacter capsulatus and their applications in decreasing purine content in the beer, beef and yeast. Naturally occurring xdhABC gene clusters of A. baumannii CICC 10254 and R. capsulatus CGMCC 1.3366 as well as two refactored clusters constructed by exchanging their xdhC genes were overexpressed in Escherichia coli and purified to near homogeneity. RcXDH chaperoned by AbXdhC showed nearly the same catalytic performance as that by RcXdhC, except for the decreased substrate affinity. While the AbXDH co-expressed with RcXdhC displayed enhanced acidic adaptation but weakened catalytic activity. All the XDHs degraded purines in beer, beef and yeast extract effectively, indicating potential applications in low-purine foods to prevent hyperuricemia and gout. The study also presents a method for exploiting the better chaperone XdhC and novel XDHs by functional complement activity using existing XdhCs such as RcXdhC.

The aim of this study was to isolate a new purine-degrading potential probiotic strain from Chinese fermented rice-flour noodles and investigate its potential application in purine-degrading food development for promising anti-gout therapy. A new lactic acid bacteria strain designated as Lactobacillus fermentum 9-4 was screened out from 10 Shengzhamifen samples by a comprehensive method integrating agar plate selection, in vitro purine-metabolizing enzymatic activities of xanthine oxidase and urate oxidase, 16S rRNA gene sequencing and identification. The resting cells of L. fermentum 9-4 showed the maximum degradation rates of inosine and guanosine by respective 2.13 × 10⁻³ and 2.78 × 10⁻³ g/(L·min), and the highest assimilation ratio of guanosine by (55.93 ± 3.12)%, which are improvements over LAB strains characterized previously. Yogurt fermented by L. fermentum 9-4 also efficiently assimilated the inosine and guanosine, with respective degradation rates of 98.10 % and 98.56 % higher than those of the commercial ones. The L. fermentum 9-4 showed excellent survival (> 80 %) under the conditions of pH 2.5 and 0.1 % bile salt. The results suggest that L. fermentum 9-4 may be a promising candidate as a probiotic for developing low-purine foods.