Protective Effect of Egg Yolk Lipids against Dextran Sulfate Sodium-Induced Colitis: The Key Role of Gut Microbiota and Short-Chain Fatty Acids.

Egg yolk lipids significantly alleviate dextran sulfate sodium (DSS)-induced colitis by inhibiting NLRP3 inflammasome, reversing gut microbiota dysbiosis, and increasing short chain fatty acids (SCFAs) concentrations. However, the role of gut microbiota and the relationship between SCFAs and NLRP3 inflammasome are still unknown. Here, this study confirms that antibiotic treatment abolishes the protective effect of egg yolk lipids on DSS-induced colonic inflammation, intestinal barrier damage, and lipopolysaccharide translocation. Fecal microbiota transplantation also supports that egg yolk lipids alleviate colitis in a gut microbiota-dependent manner. Then, the study investigates the relationship between SCFAs and NLRP3 inflammasome, and finds that SCFAs significantly suppress colitis via inhibiting colonic NLRP3 inflammasome activation and proinflammatory cytokines secretions (interleukin, IL)-1ß and IL-18, and combined treatment of SCFAs and MCC950 (NLRP3 inhibitor) shows a better activity against colitis and NLRP3 inflammasome activation. Together, these findings provide positive evidence for gut microbiorta-SCFAs-NLRP3 axis as a novel target involving in the therapy of inflammatory bowel disease.

Effects of potassium sorbate on systemic inflammation and gut microbiota in normal mice: A comparison of continuous intake and washout period.

Potassium sorbate (PS) is a widely used food preservative in the field of food industry. However, the effects of continuous intake and washout period of PS on host health are still unclear. In this study, to investigate long-term effect and after-effect of different concentrations and time points of PS, healthy mice were orally exposed to 150 mg/kg, 500 mg/kg and 1000 mg/kg of PS for 10 weeks, and washout treatment for another 5 weeks, respectively. The results indicated that PS intake for 10 weeks had no obvious effects on organs and adipose tissue, nor did it noteworthily interfere with glucolipid metabolism in the serum. However, it caused inflammatory cell infiltration in the liver, increased serum interleukin (IL)-1ß level, changed abundances of gut microbiota but failed to promote the production of short chain fatty acids in the gut. After washout period for 5 weeks, liver inflammation and IL-1ß level were decreased, and gut environment developed towards a healthier condition. Specifically, PS washout significantly increased abundance of Lachnospiraceae_NK4A136_group and the production of isobutyric acid. This study confirmed washout period eliminated negative effects from continuous intake of PS, which provided positive evidence for its safety.

Egg Yolk Lipids Alleviated Dextran Sulfate Sodium-Induced Colitis by Inhibiting NLRP3 Inflammasome and Regulating Gut Microbiota.

The increasing incidence of inflammatory bowel disease (IBD) has become a global phenomenon. Egg yolk lipids are one of the essential dietary foods, but its effects on intestinal immunity remain unclear. Here, egg yolk lipids are obtained using ethanol extraction and a total of 601 kinds of lipids are detected via lipidomics, including 251 kinds of triglycerides, 133 kinds of phosphatidylcholines, 44 kinds of phosphatidylethanolamines. Then, the study finds that egg yolk lipids significantly alleviate dextran sulfate sodium-induced colitis and reduce the production of inflammatory factors. Meanwhile, egg yolk lipids also maintain intestinal barrier integrity and decrease lipopolysaccharide translocation by alleviating intestinal structure damage and increasing the numbers of goblet cells and mucin 2. Mechanistically, egg yolk lipids attenuate colitis by inhibiting the assembly and activation of NLRP3 inflammasome. Moreover, the study also finds that egg yolk lipids reverse gut microbiota dysbiosis referring to increased relative abundance of Bacteroides acidifaciens and decrease relative abundance of Akkermansia muciniphila, as well as increased short chain fatty acids concentration in the gut. Together, the study elucidates the anti-colitis effect of egg yolk lipids and provides positive evidences for egg yolk lipids involving in dietary strategy and IBD therapy.

The Effect of Sodium Benzoate on Host Health: Insight into Physiological Indexes and Gut Microbiota.

Sodium benzoate (SB) is a common food preservative widely used in the food industry. However, the effects of SB intake on host health at different stages were still unclear. Hence, we investigated the impact of SB with three concentrations (150 mg/kg, 500 mg/kg and 1000 mg/kg) and at three stages (intake for 5-weeks, intake for 10-weeks and removal for 5 weeks) on host health in normal mice. The results showed that SB intake for 5 weeks slightly changed gut microbiota composition, but it significantly increased TG (only 150 mg/kg and 1000 mg/kg) and blood glucose levels (only 500 mg/kg) and promoted the secretion of interleukin (IL)-1ß and IL-6 (p < 0.01). However, SB intake for 10 weeks mostly maintained normal glucolipid metabolism; although, IL-1ß (p < 0.01) and IL-6 (p < 0.05) levels were also significantly increased and positively regulated the gut microbiota by significantly increasing the relative abundance of Lactobacillus and significantly decreasing the relative abundance of Ileibacterium. Meanwhile, the safety of SB for host metabolism and gut microbiota was also confirmed via a fecal microbiota transplantation experiment. In addition, we found that SB removal after 10 weeks of intake significantly increased the levels of blood glucose, insulin and HOMA-IR index, which might be attributed to gut microbiota dysbiosis. Mechanistically, these positive effects and negative effects had no close relationship with the concentration of short-chain fatty acids in the gut, which might be associated with metabolites of SB or special bacterial strains. In short, this work provided positive evidence for the safety of SB consumption within the recommended range.

Industrial Application of Protein Hydrolysates in Food.

Protein hydrolysates, which may be produced by the protein in the middle of the process or added as an ingredient, are part of the food formula. In food, protein hydrolysates are found in many forms, which can regulate the texture and functionality of food, including emulsifying properties, foaming properties, and gelation. Therefore, the relationship between the physicochemical and structural characteristics of protein hydrolysates and their functional characteristics is of significant importance. In recent years, researchers have conducted many studies on the role of protein hydrolysates in food processing. This Review explains the relationship between the structure and function of protein hydrolysates, and their interaction with the main ingredients of food, to provide reference for their development and further research.

A review on recent advances of egg byproducts: Preparation, functional properties, biological activities and food applications.

The rapid development of egg industries produced vast byproducts that have not been effectively used. In this paper, the comprehensive utilization of egg byproducts was reviewed. Protein extraction and enzymatic hydrolysis were the main used ways for recycle of egg byproducts. The fact that eggshell membrane could accelerate would healing and improve facial skin of healthy people for 12 weeks was found. However, salted egg white had poor functional properties owing to high salt and ultrafiltration was an effective technology to remove 92.93% of salt. Moreover, Defatted yolk protein had the great potential to be used as food additives and functional foods. Other egg byproducts such as egg inhibitor and eggshells also were discussed. The novel applications of egg byproducts in the food field included food additives, feeds, food packaging materials and nutraceuticals based on current knowledge, but the proportion needed to be improved. This paper would provide a new insight for comprehensive utilization of egg byproducts.

Egg yolk oils exert anti-inflammatory effect via regulating Nrf2/NF-κB pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Egg yolk oils (EYO) is a traditional Chinese medicine obtained from Gallus gallus domesticus Brisson, which has been used to treat inflammatory related diseases such as cheilitis, ulceration and acute anal fissure. However, the detailed anti-inflammatory mechanism of EYO is still unknown. AIM OF THE STUDY: The anti-inflammatory activity and mechanism of EYO were investigated in tumor necrosis factor (TNF)-α induced Caco-2 cells. MATERIALS AND METHODS: EYO was obtained by direct-heat extraction (HE), ethanol extraction (EE) and petroleum ether extraction (PE), respectively. Fatty acid compositions of three EYO were measured by gas chromatography (GC). Cell viability, enzyme-linked immunosorbent assay (ELISA), transcriptome, RT-PCR and Western blotting were also performed. RESULTS: Fatty acid compositions of three EYO were different with varied extraction methods. EYO significantly reduced interleukin (IL)-8 secretion. EYO exerted anti-inflammatory effect via coordinating regulation of Nrf2/NF-κB pathways based on the results of transcriptome, Q-PCR and Western blotting. In detail, PE and HE inhibited the NF-κB pathway, whereas EE exerted anti-inflammatory activity via the Nrf2/NF-κB pathways. CONCLUSIONS: The aforementioned results showed the anti-inflammatory mechanism of EYO. These findings might be beneficial to clinical applications of EYO.

Effect of polysaccharides on the functional properties of egg white protein: A review.

Egg white protein (EWP) was one of the high-quality protein sources and widely used in the food industries because of excellent emulsifying, gelling, and foaming properties. Polysaccharides as a natural biological macromolecule have been used to improve the functional properties of EWP. The electrostatic interaction was the main driving force between EWP and polysaccharides. However, protein-polysaccharides complexes were susceptible to environmental factors including pH, ionic strength, polymer ratio, and temperature. In this paper, the functional properties of EWP were summarized. More importantly, the effects of polysaccharides on the functional properties of EWP were highlighted and reviewed referring to emulsifying, foaming, and gelling properties. The impact of environmental factors on the protein-polysaccharides interaction were also discussed. This paper leaded to enrich research systems of protein-polysaccharides interaction and provided information for the development of new egg white-derived foods.

Biological Activities of Egg Yolk Lipids: A Review.

As one of six dietary nutrients, lipid derived from different food matrices has been extensively studied and has an appropriate application in food, medicine, and cosmetic industry. Egg is a richly nutritive food, of which proteins and lipids possess excellent functional characteristics and biological activities. In recent years, egg yolk lipid has been successively separated and investigated, such as egg yolk oil, phospholipids, and fatty acids, which have anti-inflammatory activity, antioxidant activity, cardiovascular protection, and memory improvement, involving the regulation of cell function and physiological homeostatic balance. In this paper, the biological activities and underlying benefit of egg yolk lipids and fat-soluble components have been highlighted and summarized. Meanwhile, the quantitative data of egg yolk lipids needed to achieve any of the described biological effects and recommended concentrations relevant for dietary intake are reviewed. Finally, current challenges and crucial issues of high-efficiency utilization of egg yolk lipids are also discussed.