The improvement effect of astaxanthin-loaded emulsions on obesity is better than that of astaxanthin in the oil phase.

Emulsion-based delivery systems have been reported to improve the solubility, stability and bioavailability of astaxanthin. In this study, the ability of astaxanthin-loaded emulsions (AL) to ameliorate obesity induced by a high-fat and high-sucrose diet was explored, using astaxanthin in the oil phase (ASTA) as a comparison. After the administration of AL, ASTA (30 mg per kg body weight), or saline on normal or obese mice for 4 weeks, the body fat accumulation levels, hepatic lipid contents and hepatic fatty acid profiles were detected, and AL showed better anti-obesity properties than ASTA. In an acute feeding experiment, it was first observed that the astaxanthin concentration of AL was higher than that of ASTA in the blood and liver of obese mice. What's more, AL altered the microbial co-occurrence patterns in obese mice. Some gut microbial modules that were significantly correlated with obesity-related physiological parameters were identified. Overall, the improvement effect of AL on obesity is better than that of ASTA due to their higher oral absorbability and modulating effects on the gut microbiota, and we suggest AL as a more suitable astaxanthin product type for obese bodies.

Absorbability of Astaxanthin Was Much Lower in Obese Mice Than in Normal Mice.

Astaxanthin has been favored as a health food supplement by obese consumers. However, no detailed descriptions are available concerning the absorption of astaxanthin in obese individuals. In this study, we conducted acute and chronic feeding experiments in C57BL/6J mice to study the differences in astaxanthin absorption in normal and obese bodies. The obesity condition greatly decreased astaxanthin concentration in the blood and liver, its accumulation in tissues and organs, and the bioaccessibility. This may be related to the excessive intake of sucrose, fatty acids, and cholesterol, the increased gastrointestinal motility, and the disorder of gut microbiota in the obese body. Overall, our study showed that the obese body had a far less oral absorbability of astaxanthin than a normal body, and we suggest that the recommended or approved doses of astaxanthin can be properly increased for the obese body in the hope that astaxanthin will play a more active role in obese individuals.

Astaxanthin n-Octanoic Acid Diester Ameliorates Insulin Resistance and Modulates Gut Microbiota in High-Fat and High-Sucrose Diet-Fed Mice.

Astaxanthin n-octanoic acid diester (AOD) is a type of astaxanthin connecting medium-chain fatty acids with a more stable structure. In this study, we examined the role of AOD in ameliorating insulin resistance (IR) induced by a high-fat and high-sucrose diet (HFD) as well as its effect on modulating gut microbiota in mice, with free astaxanthin (AST) as a comparison. Four groups of male C57BL/6J mice (6 weeks old; n = 10 per group) were fed with a normal control diet (NC), HFD orally administered with AOD, AST (50 mg/kg body weight), or vehicle for 8 weeks. AOD improved glucose tolerance, IR, systematic and intestinal inflammation, and intestinal integrity better than AST. Further, both AOD and AST modulated gut microbiota. A significantly higher abundance of Bacteroides and Coprococcus was found in AOD than in AST, and the predicted pathway of carbohydrate metabolism was significantly impacted by AOD. Overall, AOD may play a role in alleviating IR and inflammation with the modulating effect on microbiota in HFD-fed mice. Our findings could facilitate the development of AOD as a bioactive nutraceutical and more stable alternative to AST.

DHA-phospholipids (DHA-PL) and EPA-phospholipids (EPA-PL) prevent intestinal dysfunction induced by chronic stress.

Stress exposure can increase the appearance of intestinal dysfunction. DHA and EPA have been shown to possess significant anti-inflammatory and immuno-enhancement bioactivities. The aim of the study was to investigate whether different forms of DHA or EPA would affect intestinal barriers (including intestinal epithelium integrity and immunity responses, gut microbiota and its metabolites) in mice under chronic stress, and might therefore prevent stress induced intestinal dysfunction. Chronic stress caused a series of anomalies in the intestine, including decreased faecal water content, increased pro-inflammatory cytokines (IFN-γ, TNF-α, IL-1ß and IL-6), reduced expression levels of ZO-1, occludin and E-cadherin, and aberrant microbiota composition (especially Roseburia spp., Prevotella spp., bifidobacteria and lactobacilli) and its metabolites, mainly LPS, acetic acid, propionic acid and butyric acid. Our data indicated that both DHA-PL and EPA-PL counteracted these adverse effects effectively. In conclusion, DHA-PL and EPA-PL may effectively protect mice against intestinal dysfunction under chronic stress exposure as potential ingredients for functional food.