Anti-Obesity and Gut Microbiota Regulation Effects of Phospholipids from the Eggs of Crab, Portunus Trituberculatus, in High Fat Diet-Fed Mice.

There are resourceful phospholipids in the eggs of the crab, Portunus trituberculatus (Pt-PL). However, their components and bioactivities regarding obesity were unclear. Here, we investigated the composition of Pt-PL and their fatty acids. Moreover, its effects on obesity and gut microbiota were also evaluated in high fat diet (HFD)-fed mice. The results showed that Pt-PL contained 12 kinds of phospholipids, mainly including phosphatidylcholine (PC, 32.28%), phosphatidylserine (PS, 26.51%), phosphatidic acid (PA, 19.61%), phosphatidylethanolamine (PE, 8.81%), and phosphatidylinositol (PI, 7.96%). Polyunsaturated fatty acids (PUFAs) predominated in the fatty acids components of Pt-PL, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Animal experiments demonstrated that Pt-PL significantly alleviated body weight gain, adipose gain, hepatic gain, fasting blood glucose, serum insulin, lipid levels in serum and the liver, and systematic inflammation in HFD-fed mice. Furthermore, Pt-PL regulated gut microbiota, especially in a dramatic reduction in the ratio of Firmicutes to Bacteroidetes at phylum level, as well as significant amelioration in their subordinate categories. Pt-PL reduced fecal lipopolysaccharide and total bile acids, and elevated fecal short chain fatty acid (SCFA) concentrations, particularly acetate and butyrate. These findings suggest that Pt-PL possesses anti-obesity effects and can alter gut microbiota owing to the abundance of PUFAs. Therefore, Pt-PL may be developed as an effective food supplement for anti-obesity and regulation of human gut health.

Research Progress on the Protective Effect of Brown Algae-Derived Polysaccharides on Metabolic Diseases and Intestinal Barrier Injury.

In the human body, the intestine is the largest digestive and immune organ, where nutrients are digested and absorbed, and this organ plays a key role in host immunity. In recent years, intestinal health issues have gained attention and many studies have shown that oxidative stress, inflammation, intestinal barrier damage, and an imbalance of intestinal microbiota may cause a range of intestinal diseases, as well as other problems. Brown algae polysaccharides, mainly including alginate, fucoidan, and laminaran, are food-derived natural products that have received wide attention from scholars owing to their good biological activity and low toxic side effects. It has been found that brown algae polysaccharides can repair intestinal physical, chemical, immune and biological barrier damage. Principally, this review describes the protective effects and mechanisms of brown algae-derived polysaccharides on intestinal health, as indicated by the ability of polysaccharides to maintain intestinal barrier integrity, inhibit lipid peroxidation-associated damage, and suppress inflammatory cytokines. Furthermore, our review aims to provide new ideas on the prevention and treatment of intestinal diseases and act as a reference for the development of fucoidan as a functional product for intestinal protection.

Low Molecular Weight, 4-O-Sulfation, and Sulfation at Meta-Fucose Positively Promote the Activities of Sea Cucumber Fucoidans on Improving Insulin Resistance in HFD-Fed Mice.

Fucoidans from sea cucumber (SC-FUC) have been proven to alleviate insulin resistance in several species. However, there are few studies that clarify the relationship between their structure and bioactivity. The present study evaluated the influence of molecular weight (Mw), sulfation concentrations (Cs), and sulfation position on improving insulin resistance using SC-FUC. Results showed that fucoidans with lower Mw exerted stronger effects. Having a similar Mw, Acaudina molpadioides fucoidans (Am-FUC) with lower Cs and Holothuria tubulosa fucoidans with higher Cs showed similar activities. However, Isostichopus badionotus fucoidans (higher Cs) activity was superior to that of low-Mw Thelenota ananas fucoidans (Ta-LFUC, lower Cs). Eliminating the effects of Mw and Cs, the bioactivity of Am-FUC with sulfation at meta-fucose exceeded that of Ta-FUC with sulfation at ortho-position. Moreover, the effects of Pearsonothuria graeffei fucoidans with 4-O-sulfation were superior to those of Am-LFUC with 2-O-sulfation. These data indicate that low Mw, 4-O-sulfation, and sulfation at meta-fucose contributed considerably to insulin resistance alleviation by SC-FUC, which could accelerate the development of SC-FUC as a potential food supplement to alleviate insulin resistance.

Phosphatidylserine from Portunus trituberculatus Eggs Alleviates Insulin Resistance and Alters the Gut Microbiota in High-Fat-Diet-Fed Mice.

Portunus trituberculatus eggs contain phospholipids, whose components and bioactivity are unclear. Here, we investigated the fatty acid composition of phosphatidylserine from P. trituberculatus eggs (Pt-PS). Moreover, its effects on insulin resistance and gut microbiota were also evaluated in high-fat-diet-fed mice. Our results showed that Pt-PS accounted for 26.51% of phospholipids and contained abundant polyunsaturated fatty acids (more than 50% of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)). Animal experiments indicated that Pt-PS significantly decreased body weight and adipose weight gain, improved hyperglycemia and hyperinsulinemia, mitigated insulin resistance, and regulated circulatory cytokines. Pt-PS activated insulin receptor substrate 1 (IRS1) and increased the levels of IRS1-associated phosphatidylinositol 3-hydroxy kinase (PI3K), phosphorylated protein kinase B (Akt) protein, and plasma membrane glucose transporter 4 protein. Furthermore, Pt-PS modified the gut microbiota, inducing, especially, a dramatic decrease in the ratio of Firmicutes to Bacteroidetes at the phylum level, as well as a remarkable improvement in their subordinate categories. Pt-PS also reduced fecal lipopolysaccharide concentration and enhanced fecal acetate, propionate, and butyrate concentrations. Additionally, the effects of Pt-PS on alleviation of insulin resistance and regulation of intestinal bacteria were better than those of phosphatidylserine from soybean. These results suggest that Pt-PS mitigates insulin resistance by altering the gut microbiota. Therefore, Pt-PS may be developed as an effective food supplement for the inhibition of insulin resistance and the regulation of human gut health.

Long-Chain Bases from Sea Cucumber Alleviate Obesity by Modulating Gut Microbiota.

This study evaluated the effects of long-chain bases from sea cucumber (SC-LCBs) on modulation of the gut microbiota and inhibition of obesity in high fat diet-fed mice. Results showed that SC-LCBs exerted significant antiobese effects, which were associated with the inhibition of hyperglycemia and lipid accumulation. SC-LCBs also regulated serum adipocytokines toward to normal levels. SC-LCBs caused significant decreases in Firmicutes, Actinobacteria phylum, and obesity-related bacteria (Desulfovibro, Bifidobacterium, Romboutsia etc. genus). SC-LCBs also elevated Bacteroidetes, Proteobacteria, Verrucomicrobia phylum, and short chain fatty acids (SCFAs)-producing bacteria (Bacteroides, Lactobacillus, Lachnospiraceae_NK4A136_group etc. genus). Moreover, serum and fecal lipoplysaccharide (LPS) concentrations and its dependent toll-line receptor 4 pathway were inhibited by SC-LCBs treatment. SC-LCBs caused increases in fecal SCFAs and their mediated G-protein-coupled receptors proteins. These suggest that SC-LCBs alleviate obesity by altering gut microbiota. Thus, it sought to indicate that SC-LCBs can be developed as food supplement for the obesity control and the human gut health.

Norovirus contamination and the glycosphingolipid biosynthesis pathway in Pacific oyster: A transcriptomics study.

Noroviruses are the primary pathogens associated with shellfish-borne gastroenteritis outbreaks. These viruses remain stable in oysters, suggesting an active mechanism for virus concentration. In this study, a deep RNA sequencing technique was used to analyze the transcriptome profiles of Pacific oysters at different time points after inoculation with norovirus (GII.4). We obtained a maximum of 65, 294, 698 clean sample reads. When aligned to the reference genome, the average mapping ratio of clean data was approximately 65%. In the samples harvested at 12, 24, and 48 h after contamination, 2,223, 2,990, and 2020 genes, respectively, were differentially expressed in contaminated and non-contaminated oyster digestive tissues, including 500, 1748, and 1039 up-regulated and 1723, 1242, and 981 down-regulated genes, respectively. In particular, FUT2 and B3GNT4, genes encoding the signaling components of glycosphingolipid biosynthesis, were significantly up-regulated in contaminated samples. In addition, we found up-regulation of some immune- and disease-related genes in the MHC I pathway (PA28, HSP 70, HSP90, CANX, BRp57, and CALR) and MHC II pathway (GILT, CTSBLS, RFX, and NFY), although NoVs did not cause diseases in the oysters. We detected two types of HBGA-like molecules with positive-to-negative ratios similar to type A and H1 HBGA-like molecules in digestive tissues that were significantly higher in norovirus-contaminated than in non-contaminated oysters. Thus, our transcriptome data analysis indicated that a human pathogen (GII.4 Norovirus) was likely concentrated in the digestive tissues of oysters via HBGA-like molecules that were synthesized by the glycosphingolipid biosynthesis pathway. The identified differentially expressed genes also provide potential candidates for functional analysis to identify genes involved in the accumulation of noroviruses in oysters.

Near-infrared spectroscopy for the quality control of Sarassum fusiforme: Prediction of antioxidant capability of Sarassum fusiforme at different growth stages.

The healthy benefits of seaweed have increased its market demand in recent times. Quality control is crucial for seaweed to ensure the customers' interest and the sustainable development of seaweed farming industry. This study developed a quality control method for seaweed Sargassum fusiforme, rapid and simple, using near-infrared spectroscopy (NIR) and chemometrics for the prediction of antioxidant capacity of S. fusiforme from different growth stages, S. fusiforme was distinguished according to growth stage by partial least squares-discriminant analysis (PLS-DA) and particle swarm optimization-support vector machine (PSO-SVM). The antioxidant properties including 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging capacity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity, and ferric reducing antioxidant power (FRAP) were quantified using competitive adaptive reweighted sampling (CARS)-PLS model. Based on the spectra data preprocessed by multiplicative scatter and standard normal variate methods, the PSO-SVM models can accurately identify the growth stage of all S. fusiforme samples. The CARS-PLS models exhibited good performance in predicting the antioxidant capacity of S. fusiforme, with coefficient of determination (RP2) and root mean square error (RMSEP) values in the independent prediction sets reaching 0.9778 and 0.4018 % for ABTS, 0.9414 and 2.0795 % for DPPH, and 0.9763 and 2.4386 µmol L-1 for FRAP, respectively. The quality and market price of S. fusiforme should increase in the order of maturation < growth < seedling regarding the antioxidant property. The overall results indicated that the NIR spectroscopy accompanied by chemometrics can assist for the quality control of S. fusiforme in a more rapid and simple manner. This study also provided a customer-oriented concept of seaweed quality grading based on deep insight into the antioxidant capability of S. fusiforme at different growth stages, which is highly valuable for precise quality control and standardization of seaweed market.

Fucoidan alleviates high sucrose-induced metabolic disorders and enhances intestinal homeostasis through modulation of Notch signaling.

INTRODUCTION: The therapeutic potential of fucoidan (FUC), a natural polysaccharide, in metabolic disorders is recognized, yet its underlying mechanisms remain unclear. METHODS: We conducted investigations into the therapeutic mechanisms of FUC sourced from Sargassum fulvellum concerning metabolic disorders induced by a high-sucrose diet (HSD), employing Drosophila melanogaster and mice models. Drosophila larvae were subjected to HSD exposure to monitor growth inhibition, reduced pupation, and developmental delays. Additionally, we examined the impact of FUC on growth- and development-related hormones in Drosophila. Furthermore, we assessed the modulation of larval intestinal homeostasis by FUC, focusing on the regulation of Notch signaling. In mice, we evaluated the effects of FUC on HSD-induced impairments in intestinal epithelial barrier integrity and gut hormone secretion. RESULTS: FUC supplementation significantly enhanced pupal weight in Drosophila larvae and effectively countered HSD-induced elevation of glucose and triglyceride levels. It notably influenced the expression of growth- and development-related hormones, particularly augmenting insulin-like peptides production while mitigating larval growth retardation. FUC also modulated larval intestinal homeostasis by negatively regulating Notch signaling, thereby protecting against HSD-induced metabolic stress. In mice, FUC ameliorated HSD-induced impairments in ileum epithelial barrier integrity and gut hormone secretion. CONCLUSIONS: Our findings demonstrate the multifaceted therapeutic effects of FUC in mitigating metabolic disorders and maintaining intestinal health. FUC holds promise as a therapeutic agent, with its effects attributed partly to the sulfate group and its ability to regulate Notch signaling, emphasizing its potential for addressing metabolic disorders.

Research Progress on Biological Accumulation, Detection and Inactivation Technologies of Norovirus in Oysters.

Noroviruses (NoVs) are major foodborne pathogens that cause acute gastroenteritis. Oysters are significant carriers of this pathogen, and disease transmission from the consumption of NoVs-infected oysters occurs worldwide. The review discusses the mechanism of NoVs bioaccumulation in oysters, particularly the binding of histo-blood group antigen-like (HBGA-like) molecules to NoVs in oysters. The review explores the factors that influence NoVs bioaccumulation in oysters, including temperature, precipitation and water contamination. The review also discusses the detection methods of NoVs in live oysters and analyzes the inactivation effects of high hydrostatic pressure, irradiation treatment and plasma treatment on NoVs. These non-thermal processing treatments can remove NoVs efficiently while retaining the original flavor of oysters. However, further research is needed to reduce the cost of these technologies to achieve large-scale commercial applications. The review aims to provide novel insights to reduce the bioaccumulation of NoVs in oysters and serve as a reference for the development of new, rapid and effective methods for detecting and inactivating NoVs in live oysters.

Comprehensive evaluation of Dendrobium officinale from different geographical origins using near-infrared spectroscopy and chemometrics.

Dendrobium officinale, often used as a kind of tea for daily drinks, has drawn increasing attention for its beneficial effects. Quality evaluation of D. officinale is of great significance to ensure its health care value and safeguard consumers' interest. Given that traditional analytical methods for assessing D. officinale quality are generally time-consuming and laborious, this study developed a comprehensive strategy, with the advantages of being rapid and efficient, enabling the quality evaluation of D. officinale from different geographical origins using near-infrared (NIR) spectroscopy and chemometrics. As the quality indicators, polysaccharides, polyphenols, total flavonoids, and total alkaloids were quantified. Three types of wavelength selection methods were used for model optimization and these were synergy interval (SI), genetic algorithm (GA), and competitive adaptive reweighted sampling (CARS). From the qualitative perspective, the geographical origins of D. officinale were differentiated by NIR spectroscopy combined with partial least squares-discriminant analysis (PLS-DA) and support vector classification (SVC). The PLS models constructed based on the wavelengths selected by CARS yielded the best performance for prediction of the contents of quality indicators in D. officinale. The root mean square error (RMSEP) and coefficient of determination (Rp2) in the independent test sets were 12.7768 g kg-1 and 0.9586, 1.1346 g kg-1 and 0.9670, 0.3938 g kg-1 and 0.8803, 0.0825 and 0.7031 and for polysaccharides, polyphenols, total flavonoids, and total alkaloids, respectively. As for the origin identification, the nonlinear SVC was superior to the linear PLS-DA, with the correct recognition rates in calibration and prediction sets up to 100% and 100%, respectively. The overall results demonstrated the potential of NIR spectroscopy and chemometrics in the rapid determination of quality parameters and geographical origin. This study could provide a valuable reference for quality evaluation of D. officinale in a more rapid and comprehensive manner.

Simultaneously and quantitatively analyze the heavy metals in Sargassum fusiforme by laser-induced breakdown spectroscopy.

As a nutritious and popular seafood among consumers, Sargassum fusiforme is susceptible to the toxic heavy metals because of its strong adsorption properties. In this study, laser-induced breakdown spectroscopy (LIBS) coupled with a simple framework (only remove some noise and low-intensity variables, and then combine with PLS algorithm) was used to establish the detection models to simultaneously and quantitatively analyze the content of heavy metals arsenic (As), chromium (Cd), cadmium (Cr), copper (Cu), mercury (Hg), lead (Pb) and zinc (Zn) in Sargassum fusiforme. As comparisons, three classic variable methods of successive projections algorithm (SPA), uninformative variable elimination (UVE) and variable importance in projection (VIP) were adopted. The final results showed that six of seven heavy metal models from the TV-PLSR model were optimal. These results demonstrate that the TV-PLSR framework combined with LIBS technique is an effective framework for quantitatively analyzing the heavy metals in Sargassum fusiforme.

Chinese bayberry (Myrica rubra) phenolics mitigated protein glycoxidation and formation of advanced glycation end-products: A mechanistic investigation.

Protein glycation and formation of advanced glycation end-products (AGEs) impose threats to the human health. This study firstly investigated the inhibition of Chinese bayberry (Myrica rubra) phenolics on AGEs formation through mechanistic analysis. Four common Chinese bayberry cultivars were selected to prepare phenolic-rich extracts (CBEs) and characterized for phenolic composition, and their anti-AGE properties were evaluated in multiple in vitro systems. Total sixteen phenolics were quantified in CBEs by UPLC-ESI-MS/MS. CBEs reduced total and specific fluorescent AGEs formation in various simulating models, and protected the protein from structural modification, oxidation, and cross-linking. Mechanistic analysis unveiled that scavenging of free radicals, inactivation of transition metals, interaction with protein to form complexes, and trapping of reactive α-dicarbonyls to form adducts underlain the mechanisms of the anti-glycative actions of CBEs. Chinese bayberry fruits, especially the cultivars Biqi and Wuzi, may be a promising dietary strategy to mitigate AGEs load in the human body.

Sargassum fusiforme polysaccharide attenuates high-sugar-induced lipid accumulation in HepG2 cells and Drosophila melanogaster larvae.

Lipid accumulation is a major factor in the development of non-alcoholic fatty liver disease (NAFLD). Currently, there is a lack of intervention or therapeutic drugs against NAFLD. In this study, we investigated the ability of Sargassum fusiforme polysaccharide (SFPS) to reduce lipid accumulation induced by high sugar in HepG2 cells and Drosophila melanogaster larvae. The results indicated that SFPS significantly (p < .01) decreased the accumulation of lipid droplets in high sugar-induced HepG2 cells. Furthermore, SFPS also suppressed the expression of Srebp and Fas (genes involved in lipogenesis) and increased the expression of PPARɑ and Cpt1 (genes that participated in fatty acid ß-oxidation) in these cells. SFPS markedly reduced the content of triglyceride of the third instar larvae developed from D. melanogaster eggs reared on the high-sucrose diet. The expression of the Srebp and Fas genes in the larvae was also inhibited whereas the expression of two genes involved in the ß-oxidation of fatty acids, Acox57D-d and Fabp, was increased in the larval fat body (a functional homolog of the human liver). We also found that SFPS ameliorated developmental abnormalities induced by the high-sucrose diet. These results of this study suggest that SFPS could potentially be used as a therapeutic agent for the prevention and treatment of NAFLD.

Sargassum fusiforme Alginate Relieves Hyperglycemia and Modulates Intestinal Microbiota and Metabolites in Type 2 Diabetic Mice.

Sargassum fusiforme alginate (SF-Alg) possess many pharmacological activities, including hypoglycemic and hypolipidemic. However, the hypoglycemic mechanisms of SF-Alg remain unclear due to its low bioavailability. In this study, we evaluated the therapeutic effect of SF-Alg on high-fat diet (HFD)/streptozotocin (STZ)-induced type 2 diabetes (T2D) mice. SF-Alg intervention was found to significantly reduce fasting blood glucose (FBG), triglycerides (TG), and total cholesterol (TC), while increasing high-density lipoprotein cholesterol (HDL-c) and improving glucose tolerance. In addition, administrating SF-Alg to diabetic mice moderately attenuated pathological changes in adipose, hepatic, and heart tissues as well as skeletal muscle, and diminished oxidative stress. To probe the underlying mechanisms, we further analyzed the gut microbiota using 16S rRNA amplicon sequencing, as well as metabolites by non-targeted metabolomics. Here, SF-Alg significantly increased some benign bacteria (Lactobacillus, Bacteroides, Akkermansia Alloprevotella, Weissella and Enterorhabdus), and significantly decreased harmful bacteria (Turicibacter and Helicobacter). Meanwhile, SF-Alg dramatically decreased branched-chain amino acids (BCAAs) and aromatic amino acids (AAAs) in the colon of T2D mice, suggesting a positive benefit of SF-Alg as an adjvant agent for T2D.

Research progress on applications of calcium derived from marine organisms.

Calcium is an important mineral that plays an integral role in human health, especially bone health. Marine biological calcium is an abundant resource that is generally accepted and has a complex active structure. This review evaluates research progress on marine biological calcium with regards to its sources, use of calcium supplements, calcium bioavailability, and novel applications of marine calcium. The potential for future development and the use of products incorporating marine biological calcium in biomedical research and the pharmaceutical, health care, and food industries are also reviewed. The goal of this review is to provide a comprehensive documentation on resource utilization and product development from marine organisms.

Structure and anticoagulant activity of a sulfated fucan from the sea cucumber Acaudina leucoprocta.

A sulfated fucan was extracted, purified, and characterized from Acaudina leucoprocta (a low value sea cucumber) to better understand and utilize this species. The structure of the sulfated fucan was elucidated using chemical and modern spectroscopic analyses including HPGPC, IR, AFM, GC-MS, and NMR, and its bioactivity was investigated. Our results showed that the sulfated fucan was mainly composed of → 3)-α-L-Fucp-(1→ linkage, and that the sulfate groups were substituted at the O-2 and/or O-4 positions of the fucose ring. In detail, the sulfated fucan consisted of Fuc0S (40%), Fuc2S4S (24%), Fuc2S (24%), and Fuc4S (12%). On average, there were seven sulfate groups on every eight fucose residues. Assay for anticoagulant activity indicated that the sulfated fucan displayed intrinsic anticoagulant activity and specific anti-thrombin activity through heparin cofactor II. Our results showed that this bioactive sulfated fucan could enable the high-value utilization of this low-value sea cucumber.

Kappa-carrageenan oligosaccharides retard the progression of protein and lipid oxidation in mackerel (Scomber japonicus) fillets during frozen storage.

The antioxidative effects of κ-carrageenan oligosaccharides (CO) on the stability of proteins and lipids in mackerel fillets were determined during frozen storage. Electronic nose analysis indicated that CO treatments maintained the stability of the overall volatile flavor profiles in frozen mackerel. Protein oxidation analysis suggested that the incorporation of CO significantly retarded the rapid decrease of Ca2+-ATPase activity and active sulphydryl (A-SH) contents while also effectively inhibiting the increases in carbonyl content and surface hydrophobicity of myofibrillar proteins (MPs) compared to the control treatments. Lipid stability results showed that the peroxide values (PVs), conjugated diene (CD) content, anisidine values (AVs), and thiobarbituric acid index (TBA-i) values of the extracted lipids were also clearly reduced by CO treatments during frozen storage. Fatty acid composition determinations further confirmed that the permeated CO molecules stabilized the polyunsaturated C22:6n3 (DHA) in the lipids, most likely due to their efficient free radical scavenging activities.

Presence and Distribution of Histo-Blood Group Antigens in Pacific Oysters and the Effects of Exposure to Noroviruses GI.3 and GII.4 on Their Expression.

Noroviruses (NoVs) are one of the most important foodborne viral pathogens worldwide. Oysters are common carriers of NoVs and are responsible for their transmission. NoVs recognize human histo-blood group antigens (HBGAs) as receptors. Recent studies indicate that HBGA-like molecules also exist in oyster tissues and that they may play a key role in the binding of NoVs. However, the mechanism by which different genotypes of NoV accumulate in different oyster tissues is unknown. In this study, the presence and distribution of different types of HBGA-like molecules were evaluated in 240 oysters collected from the Shandong Peninsula of People's Republic of China for 1 year. The HBGA-like molecules were detected at various rates and expressed at different levels in different tissues. Immunohistochemistry confirmed the diversity of HBGA-like molecules in four oyster tissues. Eight types of HBGA-like molecules (types A, B, H1, Lewis x, Lewis y, Lewis a, Lewis b, and precursor) were assessed in different tissues. Of these, the type A HBGA-like molecule was consistently expressed in the gills, digestive tissue, and mantle, while types H1 and Lewis b HBGA-like molecules were expressed in the digestive tissues. The expression of HBGA-like molecules in response to the NoV challenge was investigated. The levels of types A, H1, and Lewis x increased significantly in specific oyster tissues after exposure to genogroup II, genotype 4 (GII.4) or genogroup I, genotype 3 (GI.3) NoV. The real-time reverse transcription PCR assays indicated that GI.3 NoV mainly accumulated in the digestive tissues of oysters, whereas GII.4 NoV accumulated in the gills, mantle, and digestive tissues. These results provide new insights into the mechanism of NoV bioaccumulation in oysters and suggest that NoV accumulation in oysters may be related to the expression of HBGA-like molecules.

[Research Progress in Norovirus Bioaccumulation in Shellfish].

Noroviruses (NoVs) are one of the most important foodborne viral pathogens worldwide. Shellfish are the most common carriers of NoVs as they can concentrate and accumulate large amounts of the virus through filter feeding from seawater. Shellfish may selectively accumulate NoVs with different genotypes, and this bioaccumulation may depend on the season and location. Our previous studies found various histo-blood group antigens (HBGAs) in shellfish tissues. While HBGAs might be the main reason that NoVs are accumulated in shellfish, the detailed mechanism behind NoV concentration and bioaccumulation in shellfish is not clear. Here we review current research into NoV bioaccumulation, tissue distribution, seasonal variation, and binding mechanism in shellfish. This paper may provide insight into controlling NoV transmission and decreasing the risks associated with shellfish consumption.