The relevance of DHA with modulating of host-gut microbiome signatures alterations and repairing of lipids metabolism shifts

Polysaccharides from Cistanche deserticola Ma prevent alcoholic fatty liver disease by regulating hepatic lipid metabolism and gut microbiota in mice

Cistanche deserticola Ma polysaccharide (CDP) is an active ingredient extracted from Cistanche deserticola Ma (CD) and is believed to have hepatoprotective activity. However, the molecular mechanism of its hepatoprotective effect by intervening in alcoholic fatty liver disease (AFLD) remains unclear. In the present study, three polysaccharides were isolated and purified from CD, and the polysaccharide with the better lipid-lowering and liver-protecting activity and the highest yield, CDPS, was selected by in vitro experiments for subsequent. The efficacy of CDPS in ameliorating AFLD in mice was evaluated using hepatic lipidomics, 16S rRNA analysis and molecular biology experiments. The present study showed that CDPS significantly improved alcohol-induced weight loss, lipid accumulation, ALT, AST, inflammation and dyslipidemia, suggesting that CDPS can prevent AFLD. Lipidomics showed that CDPS improved lipid metabolism disorders by regulating glycerophospholipid metabolism, linoleic acid metabolism, and arachidonic acid metabolism. 16S rRNA analysis showed that CDPS ameliorated alcohol-induced gut microbiota disruption. In particular, CDPS supplementation reduced the abundance of Bacteroides, Parabacteroides, and Escherichia-Shigella and increased the abundance of Ruminococcaceae_UCG-010, Lachnospiraceae_NK4A136_group and Faecalibaculum abundance, and promoted the production of SCFAs. We further used Western blotting to determine the levels of proteins involved in lipogenesis and catabolism, and CDPS intervention resulted in decreased levels of lipid synthesis-associated proteins (SREBP-1c and FAS) and increased levels of lipid catabolism-associated proteins (PPARα) and p-AMPK/AMPK ratio. Our results suggest that CDPS has the potential to prevent AFLD by modulating lipid metabolism, altering the gut microbiota, increasing the content of SCFAs, activating the AMPK signaling pathway to promote fatty acid β-oxidation and limiting fatty acid biosynthesis, which provides a basis for further development of therapeutic drugs for AFLD.

Modulation of gut microbiota and lipid metabolism in rats fed high-fat diets by Ganoderma lucidum triterpenoids

Ganoderma lucidum triterpenoids (GP) have been reported to help prevent and improve hyperlipidemia. Modulation of the gut microbiota was proposed as underlying factor as well as a novel measure to prevent and treat hyperlipidemia. The effects of GP on high-fat diet (HFD)-induced hyperlipidemia and gut microbiota modulation were determined in rats. Ultra-performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (UPLC-QTOF MS-MS) indicated that GP were enriched with ganoderic acids G, B, H, A, and F. After feeding with GP supplementation, serum lipid levels including total triglyceride, total cholesterol, and low-density-lipoprotein cholesterol were significantly decreased in hyperlipidemic rats. Furthermore, administration of GP also has reversed the HFD-induced gut microbiota dysbiosis, including a significant increase in Alloprevotella and reduced proportion of Blautia. The result above suggests that GP would be developed as a functional food to ameliorate lipid metabolic disorders and hyperlipidemia.

Inflammatory Signatures of Maternal Obesity as Risk Factors for Neurodevelopmental Disorders: Role of Maternal Microbiota and Nutritional Intervention Strategies

Obesity is a main risk factor for the onset and the precipitation of many non-communicable diseases. This condition, which is associated with low-grade chronic systemic inflammation, is of main concern during pregnancy leading to very serious consequences for the new generations. In addition to the prominent role played by the adipose tissue, dysbiosis of the maternal gut may also sustain the obesity-related inflammatory milieu contributing to create an overall suboptimal intrauterine environment. Such a condition here generically defined as “inflamed womb” may hold long-term detrimental effects on fetal brain development, increasing the vulnerability to mental disorders. In this review, we will examine the hypothesis that maternal obesity-related gut dysbiosis and the associated inflammation might specifically target fetal brain microglia, the resident brain immune macrophages, altering neurodevelopmental trajectories in a sex-dependent fashion. We will also review some of the most promising nutritional strategies capable to prevent or counteract the effects of maternal obesity through the modulation of inflammation and oxidative stress or by targeting the maternal microbiota.

Docosahexaenoic acid-rich fish oil alleviates hepatic steatosis in association with regulation of gut microbiome in ob/ob mice

It remains to study whether docosahexaenoic acid-rich fish oil (DHA-FO) improves hepatic lipid metabolism by leptin-independent mechanisms. We used ob/ob mice as a model to investigate the effects of DHA-FO on hepatic steatosis. DHA-FO inhibited lipid droplets (LD) formation in liver of ob/ob mice. Probably because DHA-FO consumption prevented the accumulation of oleic acid, and suppressed the synthesis of triglycerides and cholesteryl esters. These beneficial effects might be concerned with the promotion of short chain fatty acids (SCFAs) production. Furthermore, DHA-FO could reverse gut bacteria dysbiosis, including increasing the abundance of SCFAs producers (e.g. Akkermansia and unclassified_Muribaculaceae), and suppressing the proliferation of conditional pathogenic bacteria, such as unclassified_Lachnospiraceae. DHA-FO also promoted colonic microbial function ("Glycerolipid metabolism") associated with lipid metabolism. As a potential ingredient for functional food, DHA-FO reduced LD accumulation, which might be associated with modulation of obesity-linked gut microbiome in ob/ob mice.

Excess DHA Induces Liver Injury via Lipid Peroxidation and Gut Microbiota-Derived Lipopolysaccharide in Zebrafish

Being highly unsaturated, n-3 long-chain polyunsaturated fatty acids (LC-PUFAs) are prone to lipid peroxidation. In this study, zebrafish were fed with low-fat diet (LFD), high-fat diet (HFD), or 2% DHA-supplemented HFD (HFDHA2.0). To study the possible negative effects of the high level of dietary DHA, growth rates, blood chemistry, liver histology, hepatic oxidative stress, apoptosis, and inflammatory processes were assessed. The cell studies were used to quantify the effects of DHA and antioxidant on cellular lipid peroxidation and viability. The possible interaction between gut microbiota and zebrafish host was evaluated in vitro. HFDHA2.0 had no effect on hepatic lipid level but induced liver injury, oxidative stress, and hepatocellular apoptosis, including intrinsic and death receptor-induced apoptosis. Besides, the inclusion of 2% DHA in HFD increased the abundance of Proteobacteria in gut microbiota and serum endotoxin level. In the zebrafish liver cell model, DHA activated intrinsic apoptosis while the antioxidant 4-hydroxy-Tempo (tempo) inhibited the pro-apoptotic negative effects of DHA. The apoptosis induced by lipopolysaccharide (LPS) was unaffected by the addition of tempo. In conclusion, the excess DHA supplementation generates hepatocellular apoptosis-related injury to the liver. The processes might propagate along at least two routes, involving lipid peroxidation and gut microbiota-generated LPS.

Evaluating the reparative effects and the mechanism of action of docosahexaenoic acid on azithromycin-induced lipid metabolism dysfunction

To explore the reparative effects of DHA on the gut microbiome disturbance and dysfunctional lipid metabolism caused by long-term antibiotic therapy, it was tested on an azithromycin (AZI) mouse antibiotic model. Thirty specific-pathogen-free BALB/c mice (SPF grade, half male and half female) were randomly separated into three groups (n = 10, 5 male and 5 female): control group (CK), azithromycin natural recovery group (AZI) and DHA group (DHA). High-throughput sequencing and bioinformatics methods were used to analyze the gut microbiome. ELASE kits were used to measure blood lipid, lipids in the liver, and bile salt hydrolase (BSH) levels in feces. Gas chromatography and UPLC-MS/MS were employed to detect DHA and bile acids contents in liver, respectively. Real-time polymerase chain reaction (RT-PCR) was used to measure the expression of key enzymes involved in lipid metabolism. Long-term AZI treatment led to dyslipidemia, gut microbiome disturbance and anxious behaviors in the mouse model. DHA was found to significantly improve the dyslipidemia and anxiety-like behaviors induced by AZI. DHA had no effect on the structure of gut microbiome and bile acids contents but increased the content of the metabolic enzyme BSH in gut microbiota and normalized the expression of enzymes involved in lipid metabolism.