Polisaharidi iz gljive Sparassis latifolia ublažavaju štetan utjecaj prehrane s velikim udjelom masnoća i kolesterola na crijeva miševa

Research background. Sparassis latifolia polysaccharides can regulate lipids and cholesterol in serum and liver. However, little is known about the regulation mechanism of the polysaccharides on cholesterol metabolism and especially the causal relationship with gut microbiota regulation. This study will provide a theoretical basis for the cholesterol-lowering mechanism of S. latifolia polysaccharides and further development of functional foods. Experimental approach. In this study, we investigated how the regulation mechanism of Sparassis latifolia polysaccharides affects intestinal cholesterol metabolism in high-fat and high-cholesterol diet-fed rats. Briefly, enzymatic colorimetric microplate assay was used to determine the concentration of faecal bile acid. Gas chromatography-mass spectrometry was used to detect the content of cholesterol and alcohol in faeces. Haematoxylin and eosin staining method was applied to observe the changes in the structure of the small intestine tissue. The related gene expressions in jejunum and ileum were detected by real-time fluorescent quantitative polymerase chain reaction. The related protein expressions in jejunum were studied by using Western blot. High-throughput sequencing was used to detect the intestinal flora changes of the caecal contents. Gas chromatography-mass spectrometry was applied to detect the concentration of short-chain fatty acids in the caecal content. Results and conclusions. The results showed that Sparassis latifolia polysaccharides could improve the intestinal morphological structure and physiological indices in rats fed high-fat and high-cholesterol diet. Moreover, it could improve intestinal cholesterol metabolism disorder induced by high-fat and high-cholesterol diets via the reduction of the expression of HMGCR, NPC1L1, ACAT2, MTP, ASBT and IBABP mRNA or protein, increasing ABCG8 mRNA expression. In addition, it could also increase the relative abundance of Bacteroides, Butyricicoccus, Parabacteroides, Parasutteerella and Alloprevotella and the short-chain fatty acid concentration, to comprehensively regulate the intestinal cholesterol metabolism. The metabolomics analysis found that Sparassis latifolia polysaccharides could affect lipid, carbohydrate and other related metabolites. Some biomarkers associated with cholesterol metabolism correlated significantly with the abundance of specific intestinal microbiota. Novelty and scientific contribution. These findings indicate that Sparassis latifolia polysaccharides could attenuate intestinal cholesterol metabolism disorder, correlating with modulating gut microbiota and improving host metabolism. They provide theoretical support for the development of Sparassis latifolia as a new food resource.Pozadina istraživanja. Polisaharidi iz gljive Sparassis latifolia mogu regulirati udjel lipida i kolesterola u serumu i jetri. Međutim, mehanizam regulacije metabolizma kolesterola i osobito njegova povezanost s regulacijom crijevne mikrobiote slabo su poznati. U ovom je radu teorijski opisan mehanizam snižavanja udjela kolesterola pomoću polisaharida iz gljive S. latifolia, te je istražena mogućnost razvoja funkcionalne hrane s ispitanim polisaharidima. Eksperimentalni pristup. U ovom smo radu ispitali kako mehanizam regulacije polisaharida iz gljive S. latifolia utječe na metabolizam kolesterola u crijevima miševa hranjenih hranom s velikim udjelom masti i kolesterola. Ukratko, određena je koncentracija žučne kiseline u stolici pomoću kolorimetrijskog testa na mikrotitracijskim pliticama. Tekućinskom kromatografijom spregnutom s masenom spektrometrijom određeni su udjeli kolesterola i alkohola u fecesu. Promjene strukture tkiva tankog crijeva praćene su bojenjem hematoksilinom i eozinom. Ekspresije gena u jejunumu i ileumu određene su kvantitativnom lančanom reakcijom polimeraze u stvarnom vremenu, dok je ekspresija proteina u jejunumu ispitana pomoću metode Western blot. Metodom sekvenciranja visoke propusnosti praćene su promjene crijevne flore u slijepom crijevu. Koncentracija kratkolančanih masnih kiselina u slijepom crijevu određena je plinskom kromatografijom spregnutom s masenom spektrometrijom. Rezultati i zaključci. Rezultati pokazuju da polisaharidi iz gljive S. latifolia mogu poboljšati morfološku strukturu i fiziološke značajke crijeva miševa hranjenih hranom s velikim udjelom masti i kolesterola. Osim toga, s obzirom na to da smanjuju ekspresiju HMGCR, NPC1L1, ACAT2, MTP, ASBT i IBABP mRNA ili proteina, te povećavaju ekspresiju ABCG8 mRNA, polisaharidi mogu ublažiti poremećaj metabolizma kolesterola u crijevima uzrokovan masnom prehranom. Također mogu povećati broj bakterija iz rodova Bacteroides, Butyricicoccus, Parabacteroides, Parasutteerella i Alloprevotella, te koncentraciju kratkolančanih masnih kiselina, čime reguliraju metabolizam kolesterola u crijevima. Metabolomička je analiza pokazala da polisaharidi iz gljive S. latifolia mogu utjecati na lipide, ugljikohidrate i ostale metabolite. Neki su biomarkeri metabolizma kolesterola bili u bitnoj korelaciji s povećanim udjelom specifične crijevne mikrobiote. Novina i znanstveni doprinos. Dobiveni rezultati pokazuju da polisaharidi iz gljive S. latifolia mogu ublažiti poremećaj metabolizma kolesterola u crijevima te regulirati crijevnu mikrobiotu, što pozitivno utječe na metabolizam domaćina. Time je osigurana teorijska podloga za razvoj gljive S. latifolia kao novog izvora hrane

Effects of in vitro digestion and fecal fermentation on physico-chemical properties and metabolic behavior of polysaccharides from Clitocybe squamulosa

The aim of this study was to establish a human digestion model in vitro to explore the degradation characteristics of a novel high-purity polysaccharide from Clitocybe squamulosa (CSFP2). The results showed that the content of reducing sugars (CR) of CSFP2 increased from 0.13 to 0.23 mg/mL, the molecular weight (Mw) of CSFP2 decreased significantly during the saliva-gastrointestinal digestion. The constituent monosaccharides of CSFP2, including galactose, glucose, and mannose, were stable during in vitro digestion, but their molar ratios were changed from 0.023: 0.737: 0.234 to 0.496: 0.478: 0.027. The surface of CSFP2 changes from a rough flaky structure to a scattered flocculent or rod-shaped structure after the gastrointestinal digestion. However, the apparent viscosity of CSFP2 was overall stable during in vitro digestion. Moreover, CSFP2 still maintains its strong antioxidant capacity after saliva-gastrointestinal digestion. The results showed that CSFP2 can be partially decomposed during digestion. Meanwhile, some physico-chemical properties of the fermentation broth containing CSFP2 changed significantly after gut microbiota fermentation. For example, the pH value (from 8.46 to 4.72) decreased significantly (p < 0.05) after 48 h of fermentation. the OD600 value increased first and then decreased (from 2.00 to 2.68 to 1.32) during 48-h fermentation. In addition, CSFP2 could also increase the amounts of short-chain fatty acids (SCFAs) (from 5.5 to 37.15 mmol/L) during fermentation (in particular, acetic acid, propionic acid, and butyric acid). Furthermore, the relative abundances of Bacteriodes, Bifidobacterium, Catenibacterium, Lachnospiraceae_NK4A136_group, Megasphaera, Prevotella, Megamonas, and Lactobacillus at genus level were markedly increased with the intervention of CSFP2. These results provided a theoretical basis for the further development of functional foods related to CSFP2

Purification, Characterization, and Immobilization of a Novel Protease-Resistant &alpha;-Galactosidase from Oudemansiella radicata and Its Application in Degradation of Raffinose Family Oligosaccharides from Soymilk

&alpha;-galactosidase (EC 3.2.1.22) are glycosidases that catalyze the hydrolysis of &alpha;-1,6-linked D-galactosyl residues of different substrates, which has been widely applied in the food industry. Oudemansiella radicata is a kind of precious edible medicinal mushroom, which is a healthy, green, and safe food-derived enzyme source. In this study, a novel acidic &alpha;-galactosidase was purified from the dry fruiting bodies of O. radicata by ion-exchange chromatography and gel filtration, and designated as ORG (O. radicata &alpha;-galactosidase). ORG was further immobilized to obtain iORG by the sodium alginate&ndash;chitosan co-immobilization method. Then, the characterization of free and immobilized enzymes and their potential application in the removal of the RFOs from soymilk were investigated. The results showed that ORG might be a 74 kDa heterodimer, and it exhibited maximum activity at 50 &deg;C and pH 3.0, whereas iORG showed maximum activity at 50 &deg;C and pH 5.5. In addition, iORG exhibited higher thermal stability, pH stability, storage stability, and a better degradation effect on raffinose family oligosaccharides (RFOs) in soymilk than ORG, and iORG completely hydrolyzed RFOs in soymilk at 50 &deg;C within 3 h. Therefore, iORG might be a promising candidate in the food industry due to its excellent stability, high removal efficiency of RFOs from soymilk, and great reusability

Rheological properties of the mixture of Lentinan and saliva and its inhibitory effect on Streptococcus mutans

ABSTRACTLentinan (LNT) is extracted from the fruiting body of Lentinus edodes. Its active ingredient is β−1,3-dextran and has many biological activities, but its rheological characteristics and antibacterial mechanism when mixed with saliva are rarely reported. In this study, the LNT and artificial saliva (AS) mixture was used to investigate the rheological analysis and antibacterial mechanism against Streptococcus mutans (S. mutans). The results showed that the apparent viscosity of the mixture was positively correlated with the concentration, showing a shear thinning behavior and a “non-Newtonian fluid” with a pseudoplastic behavior with the increase of shear rate. In dynamic rheology, the 8% and 6% mixtures became a gel trend and viscoelastic properties, showing elasticity of weak gel at low frequencies and liquid-like viscosity at high frequencies. Moreover, the compound could damage the structures of S. mutans and increased the leakage of intracellular macromolecules, electrical conductivity, and activities of alkaline phosphatase (AKP) and β-galactoside but inhibited acid production, fluorescence intensity, and ATP synthesis by decreasing the levels of glucokinase (glk), acetate kinase (ackA), pyruvate kinase (pykf), phosphoglycerate kinase (pgk), 6-phosphofructokinase (pfk) in the glycolysis pathway. These results indicate that LNT plays a dominant role in the oral processing and antibacterial mechanism against S. mutans. It can provide an excellent theoretical basis for studying LNT as a functional food raw material

DataSheet1_A new type of calcium-rich biochars derived from spent mushroom substrates and their efficient adsorption properties for cationic dyes.docx

Adsorption is commonly accepted as a most promising strategy in dye wastewater treatment, and the widespread use of adsorption emphasizes the need to explore low-cost but excellent adsorbents. Herein, a low-cost adsorbent (calcium-rich biochar) was developed, which was directly pyrolyzed from spent mushroom substate without any modification. This study evaluated the potential application of two calcium-rich biochars (GSBC and LSBC) derived from spent substrates of Ganoderma lucidum and Lentinus edodes, respectively. The effects of pyrolysis temperature on the calcium-rich biochars characteristics and their adsorption mechanism for cationic dyes (Malachite Green oxalate (MG) and Safranine T (ST)) were studied systematically. The increase in pyrolysis temperature from 350 to 750 °C led to an increase in both biochar ash, Ca content, and specific surface area, which made high-temperature biochars (GS750 and LS750) the superior adsorbents for cationic dyes. Batch adsorption results showed LS750 was more efficient to adsorb dyes than GS750 attributed to its higher Ca content and larger specific surface area. According to the Langmuir model, LS750 had high adsorption capacities of 9,388.04 and 3,871.48 mg g−1 for Malachite green and ST, respectively. The adsorption mechanism of dye MG could be attributed to pore filling, hydrogen bonding, electrostatic interaction, ion exchange, and π-π stacking, while ST adsorption mainly involved pore filling, electrostatic interaction, ion exchange, and π-π stacking. Attributed to their excellent adsorption performance, cheap source, and good reusability, biochars obtained from SMSs were very promising in dyeing wastewater treatment.</p