Dietary Lipid Research Articles

El glutamato monosódico en alimentos preparados: Impacto en los alimentos y su efecto en la salud

Monosodium glutamate (MSG) is a substance responsible for producing the taste known as umami. It is believed that its consumption generates an increase in appetite, a decrease in body weight gain, in addition to the variation of some blood metabolic markers such as glucose, total cholesterol and triglycerides. Most of the commercial foods have deleterious effects on human health due to the high percentages of saturated fatty acids, trans fatty acids and hydrogenated fats in the form of high lipid diet. In addition, MSG is added by food manufacturers to improve flavor and palatability. The objective of this review is to analyze the consequences of the consumption of this food additive and its effects on health. MSG as an additive influences the hypothalamic regulation of appetite, favoring a high consumption of foods that contain it. This review formulates health care strategies to raise global awareness of the harmful impact of MSG and recommends daily consumption of antioxidant-rich natural foods instead of MSG.

Monocyte Trafficking and Polarization Contribute to Sex Differences in Meta-Inflammation.

Obesity is associated with systemic inflammation and immune cell recruitment to metabolic tissues. Sex differences have been observed where male mice challenged with high fat diet (HFD) exhibit greater adipose tissue inflammation than females demonstrating a role for sex hormones in differential inflammatory responses. Circulating monocytes that respond to dietary lipids and chemokines and produce cytokines are the primary source of recruited adipose tissue macrophages (ATMs). In this study, we investigated sexual dimorphism in biological pathways in HFD-fed ATMs from male and female mice by RNA-seq. We also conducted chemotaxis assays to investigate sex differences in the migration of monocytes isolated from bone marrow from male and female mice toward a dietary saturated lipid — palmitate (PA), and a chemokine — monocyte chemoattractant protein 1 (MCP1), factors known to stimulate myeloid cells in obesity. ATM RNA-Seq demonstrated sex differences of both metabolic and inflammatory activation, including pathways for chemokine signaling and leukocyte trans-endothelial migration. In vivo monocyte transfer studies demonstrated that male monocytes traffic to female adipose tissue to generate ATMs more readily. In chemotaxis assays, lean male monocytes migrated in greater numbers than females toward PA and MCP1. With short-term HFD, male and female monocytes migrated similarly, but in chronic HFD, male monocytes showed greater migration than females upon PA and MCP1 stimulation. Studies with monocytes from toll-like receptor 4 knockout mice (Tlr4-/- ) demonstrated that both males and females showed decreased migration than WT in response to PA and MCP1 implying a role for TLR4 in monocyte influx in response to meta-inflammation. Overall, these data demonstrate the role of sexual dimorphism in monocyte recruitment and response to metabolic stimuli that may influence meta-inflammation in obesity.

Dietary lipid droplet structure in postnatal life improves hepatic energy and lipid metabolism in a mouse model for postnatal programming

Early-life diets may have a long-lasting impact on metabolic health. This study tested the hypothesis that an early-life diet with large, phospholipid-coated lipid droplets (Concept) induces sustained improvements of hepatic mitochondrial function and metabolism. Young C57BL/6j mice were fed Concept or control (CTRL) diet from postnatal day 15 (PN15) to PN42, followed by western style (WSD) or standard rodent diet (AIN) until PN98. Measurements comprised body composition, insulin resistance (HOMA-IR), tricarboxylic acid (TCA) cycle- and β-oxidation-related hepatic oxidative capacity using high-resolution respirometry, mitochondrial dynamics, mediators of insulin resistance (diacylglycerols, DAG) or ceramides) in subcellular compartments as well as systemic oxidative stress. Concept feeding increased TCA cycle-related respiration by 33% and mitochondrial fusion protein-1 by 65% at PN42 (both p 0.05). At PN98, CTRL, but not Concept, mice developed hyperinsulinemia (CTRL/AIN 0.22 ± 0.44 vs. CTRL/WSD 1.49 ± 0.53 nmol/l, p 0.05 and Concept/AIN 0.20 ± 0.38 vs. Concept/WSD 1.00 ± 0.29 nmol/l, n.s.) and insulin resistance after WSD (CTRL/AIN 107 ± 23 vs. CTRL/WSD 738 ± 284, p 0.05 and Concept/AIN 109 ± 24 vs. Concept/WSD 524 ± 157, n.s.). WSD-induced liver weight was 18% lower in adult Concept-fed mice and β-oxidation-related respiration was 69% higher (p 0.05; Concept/WSD vs. Concept/AIN) along with lower plasma lipid peroxides (CTRL/AIN 4.85 ± 0.28 vs. CTRL/WSD 5.73 ± 0.47 µmol/l, p 0.05 and Concept/AIN 4.49 ± 0.31 vs. Concept/WSD 4.42 ± 0.33 µmol/l, n.s.) and were in part protected from WSD-induced increase in hepatic cytosolic DAG C16:0/C18:1. Early-life feeding of Concept partly protected from WSD-induced insulin resistance and systemic oxidative stress, potentially via changes in specific DAG and mitochondrial function, highlighting the role of early life diets on metabolic health later in life.

Dose response relationships between linseed or rapeseed oils supply and rumen microbial metabolism in continuous culture on maize silage-based diet

Little quantitative information is available on how dietary lipids concurrently alter the main rumen microbial functions in relation with their incorporation level. In a three-period experiment, linseed (Linum usitatissimum, LO) and rapeseed (Brassica napus L., RO) oils were added at 0, 40 or 80 g/kg dry matter input (DMI) to five 1-L dual outflow fermenters that were on a maize silage-based diet for nine days per period. RO supply decreased butyrate specific production. The amount of hexoses fermented (HF) increased by 9% at 40 g/kg LO. The production of CH4 was lower at 80 g/kg LO by 46% compared with controls. Conversely, the supply of LO significantly increased H2 and H2S productions in an antagonistic mode. The specific productions of propionate, butyrate, CH4 and H2 were altered by LO. The supply of RO increased the ammonia daily outflow (by 23% at 40 g/kg) and decreased the organic N outflow (by 13% at 80 g/kg). The degradabilities of dietary fractions were not affected by RO, neither the OM partitioning between dietary, fermented and microbial outflows. The OM true degradability decreased at 80 g/kg LO compared with controls and 40 g/kg LO. When LO was supplied, isovalerate and ammonia-N outflows were higher, organic and microbial N outflows and EMPS were lower along with changes in the OM outflow partitioning. Overall microbial processes appeared to differ in their responses to fatty acids saturation. Moreover, most effects were present at 40 g/kg DMI and diminished or even plateaued at 80 g/kg DMI. Highlights Four per cent oil lowered butyrate specific production Four per cent Linseed oil lowered microbial protein synthesis efficiency Linseed oil lowered methanogenesis in proportion to input level

Response of lipid-related composition of farmed tiger puffer (Takifugu rubripes) to starvation under different dietary lipid levels in the previous feeding period

Starvation is a natural process in the life cycle of wild fish, and also a means of body composition regulation for farmed fish. This study with tiger puffer was aimed at investigating the effects of starvation on lipid and fatty acid compositions in fish with different levels of lipid accumulation. Different lipid accumulation levels in tiger puffer were obtained by manipulating the dietary lipid content (8%, 12%, and 16%) in a previous feeding period for 9 weeks. Each diet was fed to sextuplicate net cages in this feeding trial. At the end of the feeding trial, fish with an average initial body weight of 68.26 g were then subjected to starvation for 31 days. Tissue samples were collected at the end of the feeding trial and at 1, 4, 9, 16, and 31 days after starvation. The results showed that the muscle lipid content decreased linearly with starvation time, but the liver lipid content increased firstly (1–16 days of starvation), and thereafter sharply declined. However, no interaction between starvation time and dietary lipid level was observed in the effects on liver and muscle lipid composition. Starvation had slight effects on muscle and liver fatty acid compositions, except that it largely increased the C22:5n-3 content in the muscle. Starvation primarily mobilized C14:0, C16:1n-7, C20:1n-9 and C22:1n-9 in the muscle, and C18:0, C18:1n-9, and EPA in the liver. Interactive effects between starvation time and dietary lipid level were observed for many fatty acids. Short-term (1–4 days) starvation increased the muscle texture parameters, but longer-term starvation decreased them. In conclusion, starvation exerts significant effects on lipid and fatty acid composition in farmed tiger puffer. Customed lipid and fatty acid composition, and possibly customed fillet quality could be obtained through manipulation of starvation time and dietary lipid level in the previous feeding period.

Tissue Distribution and Nutritional Regulation of Fatty Acid-Binding Proteins (fabps) in Two Marine Teleosts, Turbot (Scophthalmus maximus), and Tiger Puffer (Takifugu rubripes)

Fatty acid-binding proteins (fabps) play important roles in lipid homeostasis. In the present study, 7 fabp isoforms, namely, fabp1, fabp2, fabp3, fabp4, fabp6, fabp7, and fabp10, in two marine teleosts, were characterized. In general, turbot and tiger puffer fabp genes showed high identity to their orthologs in other fish species and mammals, but tiger puffer Fabp6 shared the lowest identity to its known orthologs in zebrafish and human. The tissue distribution patterns of fabps were generally in accordance with their function features. However, tiger puffer fabps, in particular Fabp1, Fabp2, Fabp6 and Fabp7, may have functions distinct from other teleosts, as indicated by the phylogenetic tree and tissue distribution patterns. In both species, high dietary lipid levels downregulated the expression of fabp2, fabp3, fabp6, and fabp7a but tended to upregulate the fabp1 expression. Starvation downregulated the expression of most fabps in both fish species, but the downregulation of fabp expression in turbot was much more drastic and earlier compared to tiger puffer. Long-term (30-day) starvation increased the fabp7 expression in tiger puffer and tended to increase the fabp6 expression in turbot. Results of this study contribute to fish fabp physiology and its nutritional regulation.

Mediterranean Dietary Treatment in Hyperlipidemic Children: Should It Be an Option?

Background: Diet is considered the cornerstone of lipid management in hyperlipidemic children but evidence to demonstrate the effects of nutrient benefits on the lipid profile is limited. Aim: The aim of this study is to evaluate the impact of the Mediterranean diet on low-density lipoprotein (LDL-C) and non-high density lipoprotein (HDL-C) decrease in primary hyperlipidemia affected children and in the achievement of therapeutical target levels. Methods: A retrospective cohort study was used, recruiting n = 223 children (10.05 ± 3.26 mean age years) with familial hypercholesterolemia (FH) (n = 61, 27%) and polygenic hypercholesterolemia (PH) (n =162, 73%). Secondary hyperlipidemias were excluded. Based on LDL-C and non-HDL-C decrease, participants were divided into two groups, named the Responder Group and Non-Responder Group. Participants and their families underwent dietary education by an expert nutritionist and were asked to fill in a weekly diary to be delivered at visits. Dietary indications were in line with daily caloric requirement, daily food quality and quantity intakes typical of the Mediterranean diet. These include carbohydrates, extra virgin olive oil, yoghurt and milk derivatives, fish and vegetable proteins, fresh seasonal vegetables and fresh fruits. Nuts or almonds were also recommended. The advice to limit intakes of meat, in particular red meat, and caution against junk food and sugar added food and beverages was provided. At medical visits, carried out at baseline (T0) and 6 months later (T1), children underwent anthropometric measurements and blood collection. Standard kits and methods were applied for lipid analysis. Statistical methods were performed by SAS version 9.4 (SAS Institute, Cary, NC, USA). Signed informed consent was given by parents according to the Declaration of Helsinki and the study was approved by the Local Committee. Results: The Responder Group (n = 156/223, 70%) included 45 FH and 111 PH children, while the Non-Responder Group (n = 67/223, 30%) included 16 FH and 51 PH children. The Responder Group showed total cholesterol (TC), LDL-C and non-HDL-C median percentage decreases of 9.45, 13.51 and 10.90, respectively. These statistically significant changes (p ≤ 0.0001) were similar in the FH and PH subgroups but just PH subjects reached the LDL-C and non-HDL-C target, which fell below 130 mg/dL and 145 mg/dL, respectively. Saturated fatty acids (SFAs) were the main dietary parameter that distinguished between the Responder Group and the Non-Responder Group (p = 0.014). Positive correlations were found at T1 between dietary total lipids, SFAs and cholesterol with serum LDL-C, non-HDL-C and TC variations. These latter serum parameters had an inverse correlation with dietary carbohydrate at T1. Among macronutrients, SFAs were finally demonstrated to be the predictor of serum lipids variation at T1. Conclusions: The dietary intervention with a Mediterranean diet in children with primary hyperlipidemia significantly improves the lipid profile both in FH and PH subgroups and allows target levels of LDL-C and non-HDL-C in PH subjects to be reached. Responsiveness benefits should be primarily attributed to the reduction in SFAs, but changes in dietary lipids, cholesterol and carbohydrate intake may also play a role. In contrast, the Non-Responder Group showed a worsening of lipid profile regarding the unchanged diet.

Fungal digestive enzymes promote macronutrient hydrolysis in the INFOGEST static in vitro simulation of digestion

The objective of this study was to test the hydrolytic efficacy of 6 fungal enzymes in the INFOGEST static in vitro simulation of gastrointestinal (GI) digestion. First, the INFOGEST protocol was adapted for testing of exogenous enzymes. Second, a dose-response study of 3 individual fungal proteases, a lipase, and an amylase with glucoamylase demonstrated improved dietary protein, lipid, and carbohydrate hydrolysis, respectively, from an oral nutritional supplement (ONS) under simulated gastric or GI conditions, compared to pepsin and pancreatin-based control conditions. Third, a combination of the 6 enzymes (BC-006) improved macronutrient digestion, including enhanced release of individual amino acids from ONS and mixed meal substrates. Finally, we validated digestive models of aging and proton pump inhibitor (PPI) use, and showed that BC-006 improved gastric digestion under these compromised digestive conditions. The INFOGEST static simulation is a feasible tool to rapidly screen and profile exogenous enzymes for digestive efficacy in vitro.

Effects of Hypericum perforatum on serum lipid vascular systems in mice

Herbal products are increasingly used against lipid to attenuate its negative impact on vasculature system. However, there are uncertainty regarding the best administration approaches and preparation of herbal product to be used due to variation in absorption rate and extent with subsequent impaction on the lipid levels. The aim of the present study was comparing the pharmacological and analytical aspects of soaked versus powder form of Hypericum perforatum; a well-known anti-hyperlipidemic herbal product, using atorvastatin drug as a reference drug for comparison in addition to controlling groups (on/off lipid diet) handled as an additional control group. To conduct this research, the hyperlipidemia mice models were created by exposing the mice to a fatty diet and using H. perforatum and atorvastatin for evaluation. The plant extracts were also analyzed for active constituents. The results indicate that the plant analysis detected the presence of different antihyperlipidemic agents and the plant has effectively reduced plasma lipid parameters in exposed mice compared to control group; especially when taken forms of the plant was used. The study concluded that; soaked H. perforatum extract shown an effective reduction of lipid parameters and analysis of which revealed the presence of herbal active constituent which might be utilized in industrial pharmacy for new drug innovation.

Effects of Pantothenic Acid on Growth Performance, Oxidative Stress, and Lipid Content in High-Fat-Fed Megalobrama amblycephala

This study was to elucidate the effects of dietary pantothenic acid (PA) on growth, lipid metabolism, and antioxidant status in juvenile blunt snout bream Megalobrama amblycephala. Fish were fed with four experimental diets containing two lipid levels (5% and 11%) and two PA supplementation levels (24 mg kg-1 and 240 mg kg-1) for eight weeks. The results showed that diets containing 11% lipid significantly increased condition factor, mesenteric fat index, triacylglycerol (TG), and cholesterol (TCH) in the liver as well as total lipid content and TCH in the muscle ( P < 0.05 ), but significantly decreased specific growth rate and whole-body protein ( P < 0.05 ). As the dietary lipid level increased, hepatic antioxidant enzyme activities were significantly increased ( P < 0.05 ) as well as malondialdehyde content ( P < 0.05 ). Besides, cytosolic cytochrome c concentration was also significantly ( P < 0.05 ) increased, while mitochondrial protein, cytochrome c, and Na+-K+-ATPase activities were significantly decreased ( P < 0.05 ). There were no significant changes on growth performance and body composition of PA supplementation. Then, significantly negative ( P < 0.05 ) interactions were observed between dietary lipid and PA supplementation on EPA, DHA, and EPA + DHA content of the muscle. Saturated fatty acid (SFA) and polyunsaturated fatty acid (PUFA) contents in the liver were significantly increased ( P < 0.05 ) with dietary lipid level increased, while liver monounsaturated fatty acid (MUFA) was significantly decreased ( P < 0.05 ). Muscle SFA, DHA, and EPA + DHA contents were significantly decreased ( P < 0.05 ) when dietary fat level increased. Meanwhile, EPA, DHA, and EPA + DHA content was significantly decreased ( P < 0.05 ) with dietary high PA supplementation. On the whole, a high PA supplementation level of 240 mg kg-1 could alleviate lipid content accumulated and oxidative damage induced by a high-fat diet.

Effects of dietary lipid, L-carnitine and L-lysine supplementation on the growth performance and body composition of Epinephelus lanceolatus larvae

The effects of different combinations of dietary lipid, L-carnitine and L-lysine on the growth performance and fatty acid profiles of larval grouper Epinephalus lanceolatus were evaluated. Eight treatment diets were formulated based on a 2x2x2 factorial design, namely 5 and 14% dietary oil mixture (3:1 fish oil/soybean oil), 0 and 0.5% L-carnitine and 0 and 2.83% L-lysine. Each diet was randomly assigned to triplicate groups of ten 0.08g E. lanceolatus larvae for 42 days. The grouper larvae fed with diets containing 14% lipid had significantly higher weight gain percentages than those fed with diets containing 5% lipid. The weight gain percentage of the grouper larvae fed with a diet containing both 14% lipid and 0.5% L-carnitine without added L-lysine was found to be the highest, while the addition of dietary 2.83% L-lysine failed to have any additive effect on the growth performance. With the dietary lipid being 14%, not only dietary L-carnitine but also L-lysine is able to decrease lipid and increase protein levels in grouper muscle. The supplementation of dietary L-carnitine with a high level of lipid is also able to reduce liver lipid level of groupers. The levels of n-3 highly unsaturated fatty acid (n-3 HUFA) analyzed from muscle and liver of grouper larvae fed with diets supplemented with L-carnitine were significantly lower than those of grouper larvae fed with diets devoid of L-carnitine. This study indicated that the diets containing a high lipid level supplemented with L-carnitine are able to enhance the growth performance of grouper larvae.

Effect of dietary lipid levels on the anti-oxidant responses, initial immunity, and mTOR signaling in the liver of coho salmon (Oncorhynchus kisutch)

In the present study, we evaluated the effects of dietary lipid levels on the anti-oxidant responses, initial immunity, and mTOR signaling in the liver of coho salmon Oncorhynchus kisutch. The post-larval coho salmon were fed four isonitrogenous experimental diets with crude lipid levels of 6.6%, 10.56%, 18.91%, and 26.91% for 12 weeks, respectively. Compared to the control group (6.6% dietary lipid level), the activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), peroxidase (POD), glutathione peroxidase (GSH-PX), and total antioxidant capacity (TAC) were enhanced by 10.56% and 18.91% dietary lipid levels in the liver of coho salmon. However, no significant difference was observed on these anti-oxidant enzyme activities when the fish were fed 26.91% lipid level diet. Compared to the control group (6.6% dietary lipid level), the content of hydrogen peroxide (H2O2) and malondialdehyde (MDA) as well as the generation of hydroxy radical (·OH) and superoxide anion (O2·-) were decreased by 10.56% and 18.91% dietary lipid levels. In addition, the gene and protein expression level of PI3K, Akt, and mTOR was induced by 10.56%, 18.91%, and 26.91% dietary lipid levels. The gene expression level of IL-1β, IL-6, and TNFα was also increased with the increase of dietary lipid levels. The result of hepatic tissue sections showed that the cellular morphology of liver was affected by the higher dietary lipid levels. In conclusion, the dietary lipid levels affected the anti-oxidant responses, initial immunity, and mTOR signaling in the liver of post-larval coho salmon.

2-Arachidonoyl glycerol suppresses gastric emptying via the cannabinoid receptor 1-cholecystokinin signaling pathway in mice.

2-Monoacylglycerol (2-MAG) is one of the digestion products of dietary lipids. We recently demonstrated that a 2-MAG, 2-arachidonoyl glycerol (2-AG) potently stimulated cholecystokinin (CCK) secretion via cannabinoid receptor 1 (CB1) in a murine CCK-producing cell line, STC-1. CCK plays a crucial role in suppressing postprandial gastric emptying. To examine the effect of 2-AG on gastric emptying, we performed acetaminophen and phenol red recovery tests under oral or intraperitoneal administration of 2-AG in mice. Orally administered 2-AG (25mg/kg) suppressed the gastric emptying rate in mice, as determined by the acetaminophen absorption test and phenol red recovery test. Intraperitoneal administration of a cholecystokinin A receptor antagonist (0.5 mg/kg) attenuated the gastric inhibitory emptying effect. In addition, both oral (10 mg/kg) and intraperitoneal (0.5 mg/kg) administration of a CB1 antagonist counteracted the 2-AG-induced gastric inhibitory effect. Furthermore, intraperitoneal 2-AG (25mg/kg) suppressed gastric emptying. These results indicate that 2-AG exhibits an inhibitory effect on gastric emptying in mice, possibly mediated by stimulating both CCK secretion via CB1 expressed in CCK-producing cells and acting on CB1 expressed in the peripheral nerves. Our findings provide novel insights into the 2-MAG-sensing mechanism in enteroendocrine cells and the physiological role of 2-MAG.

Effects of dietary lipid levels on growth, feed utilization, RNA/DNA ratio, digestive tract enzyme activity, non-specific immune response and optimum inclusion in feeds for fingerlings of rohu, Labeo rohita (Hamilton)

The current investigation was conducted to assess the effects of different levels of dietary lipid on growth performance, feed utilization, digestive tract enzyme activity, lipid deposition, and non-specific immune response of fingerling Labeo rohita (2.23 ± 0.06 g). Six isonitrogenous (400 g kg−1) purified diets with increasing levels of lipid (20, 40, 60, 80, 100, 120 g kg−1 diet) were fed to triplicate groups of 30 fish per tank at 08:00, 12:00, and 16:00 h to apparent satiety for 8 weeks. Absolute weight gain (AWG), specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), protein retention efficiency (PRE) and RNA:DNA ratio improved significantly (P < 0.05) up to 100 g kg−1 lipid in diet. Somatic indices and whole body lipid positively correlated with the increase in dietary lipid. Dietary lipid levels significantly affected hepatic antioxidant activities. Liver superoxide dismutase (SOD) and catalase (CAT) activities improved significantly up to 100 g kg−1 lipid in diet. However, liver thiobarbituric acid reactive substances activity (TBARS), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) activities showed a negative correlation with the increase in levels of lipid in the diets. Highest intestinal protease and lipase activity was also noted in fish received 100 g kg−1 lipid in diet. Second-order polynomial analysis of AWG, FCR, RNA/DNA ratio, SOD and serum lysozyme activity against varying levels of dietary lipid reflected the requirement in the range of 94.77–98.35 g kg−1 dietary lipid for optimum growth of L. rohita.

The Lipid-Lowering Effect of Dietary Taurine in Orange-Spotted Groupers (Epinephelus coioides) Involves Both Bile Acids and Lipid Metabolism

An 8-week feeding trial was conducted to investigate how dietary taurine supplementation attenuates the lipid deposition induced by dietary high lipid in juvenile orange-spotted grouper (Epinephelus coioides). Three isonitrogenous (47% crude protein) semipurified diets were formulated to contain two levels of lipid and termed as 10% lipid diet, 15% lipid diet, and 15% lipid with 1% taurine (namely, diet 10L, diet 15L, and diet 15L + T, respectively). Groupers fed diet 15L + T showed higher weight gain and feed efficiency compared with diet 15L. Groupers fed diet 15L showed higher liver lipid contents, plasma total cholesterol (TC), and leptin contents vs. those fed diet 10L. Diet 15L + T decreased hepatosomatic index, liver lipid content, and plasma TC and adiponectin contents, and increased liver 3-hydroxy-3-methy1 glutary1 coenzyme A reductase content compared with diet 15L. Fish fed diet 15L had higher contents of chenodeoxycholic acid, deoxycholic acid, and lithocholic acid, and lower contents of glycodeoxycholic acid (GDCA), glycolithocholic acid, glycoursodeoxycholic acid, taurodeoxycholic acid (TDCA), and β-, γ-, and ω-muricholic acid (MCA) when compared with fish fed diet 10L. Diet 15L + T downregulated the contents of glycocholic acid, glycochenodeoxycholic acid, taurohyodeoxycholic acid, tauromuricholic acid, TDCA, ursodeoxycholic acid, GDCA, and β-MCA vs. diet 15L. Diet 15L upregulated expression of peroxisome proliferator-activated receptor α (pparα) gene but downregulated expression of acyl-CoA carboxylase (acc), fatty acid synthase (fas), and glucose-6-phosphate dehydrogenase (g6pd) genes in comparison with diet 10L. The gene expression level of fas and 6pgd was downregulated and the pparα gene expression level was upregulated in fish fed diet 15L + T compared with those in fish fed diet 15L. Overall, this study indicated that dietary taurine supplementation can attenuate the liver lipid deposition of groupers caused by feeding 15% lipid through accelerating lipid absorption of taurine-conjugated bile acids and fatty acid β-oxidation and inhibiting lipogenesis.

Effect of vitamin A supplement on the growth performance, antioxidant status, and lipid accumulation of Chinese mitten crab Eriocheir Sinensis fed different lipid levels

This study evaluates the influence of dietary vitamin A on growth performance, antioxidant capacity, and lipid metabolism of Eriocheir sinensis juveniles (3.95 ± 0.12 g) fed different lipid levels. Crabs were fed with four diets, including normal lipid (7%) with vitamin A devoid (0 IU/kg, NL-VAD), normal lipid (7%) with vitamin A supplement (6000 IU/kg, NL-VAS), high lipid (13%) with vitamin A devoid (0 IU/kg, HL-VAD), and high lipid (13%) with A supplement (6000 IU/kg, HL-VAS) for 8 weeks. The significant interaction between dietary vitamin A and lipid level was found in weight gain, specific growth rate, and the mRNA of lipid synthesis related genes and retinoid X receptor. Under high lipid diets, vitamin A supplementation did not affect final body weight, weight gain, specific growth rate. Regardless of dietary lipid levels, vitamin A enhanced the activities of relevant antioxidant indices (total antioxidant capacity, superoxide dismutase, and glutathione peroxidase). Vitamin A supplementation also reduced the excessive malondialdehyde in the hepatopancreas caused by high-fat diets. In the high lipid group, dietary vitamin A reduced hepatosomatic index, total lipid in the whole body and hepatopancreas, and triglyceride and free fatty acids in the hepatopancreas. Vitamin A supplementation reduced lipid accumulation in the crab fed high lipid diets by promoting genes expression about lipid oxidation and transport. Under high lipid diets, restrained lipid synthesis was found in the vitamin A supplementation group compared with the vitamin A-free group. This research suggests that dietary vitamin A can ameliorate lipid peroxidation and promote lipid utilization by optimizing lipid metabolism in E. sinensis fed a high-fat diet.

Effect of diets containing full-fat Hermetia illucens on rainbow trout microbiota: A dual cultivation-independent approach with DGGE and NGS

Given the drift to improve economic and ecological sustainability of the aquaculture sector, novel ingredients fulfilling these requirements are sought. Hermetia illucens, commonly called black soldier fly, (Diptera: Stratiomydae; H) is a promising dietary protein source but its effect on fish gut microbiota is still to be clarified. The aim of the present study was to increase the knowledge of the effect of dietary full-fat H meal on rainbow trout (Oncorhynchus mykiss) microbiota and, in particular, on intestinal mucosa-adherent microbiota by applying a dual approach based on polymerase chain reaction-denaturing gradient gel electrophoresis and high-throughput sequencing of the 16S rRNA gene. Rainbow trout (initial body weight of 137.3 ± 10.5 g) was fed for 98 days with a control diet (H0) containing fishmeal and protein-rich vegetable ingredients and an experimental diet (H50) where 50% of the fishmeal had been replaced by full-fat H meal rich in saturated fatty acids.Proteobacteria, Firmicutes and Actinobacteria were generally present in all samples, although the core microbiota (relative prevalence higher than or equal to 80% in all samples) only consisted of the proteobacteria Caulobacter, Delftia, Agrobacterium and Ochrobactrum. In addition, Streptococcus infantis and a member of the Cytophagaceae family were part of the core taxa of mucosa samples. Tenericutes were abundant in pyloric caeca samples and, among them, Mycoplasmataceae seemed to increase in the group fed the high saturated fatty acid diet containing H meal; a consideration about the connection between this bacterial group and the dietary lipid content must be considered. Dietary treatment did not clearly affect alpha-diversity metrics, but mucosa samples tended to be more resilient to dietary changes than content samples. Permutational analysis of variance showed significantly different β-diversities between diets (p < 0.05) but principal coordinates analysis did not confirm this result.Diets for rainbow trout containing full-fat H meal determined interesting modifications in the gut microbiota with patterns similar to the ones found in the literature. The dietary lipids can exert an effect on microbiota. Nonetheless, research data on this topic are still scarce and further studies are highly encouraged.

DO-SRS imaging of diet regulated metabolic activities in Drosophila during aging processes.

Lipid metabolism plays crucial roles during aging processes, but how it is regulated by diets and how it interplays with aging still remain unclear. We proposed a new optical imaging platform by integrating heavy water (D2O) probing with stimulated Raman scattering (DO‐SRS) microscopy, for the first time, to directly visualize and quantify lipid metabolism regulated by different diets and insulin signaling pathway in Drosophila fat body during aging. We found that calorie restriction, low protein diet, and (moderately) high protein and high sucrose diets enhanced lipid turnover in flies at all ages, while (moderately) high fructose and glucose diets only promoted lipid turnover in aged flies. The measured lipid turnover enhancements under diverse diets were due to different mechanisms. High protein diet shortened the lifespan while all other diets extended the lifespan. Downregulating the insulin signaling pathway enhanced lipid turnover, which is likely related to lifespan increase, while upregulating insulin signaling pathway decreased lipid turnover that would shorten the lifespan. Our study offers the first approach to directly visualize spatiotemporal alterations of lipid turnover in aging Drosophila in situ, for a better understanding of the interconnections between lipid metabolism, diets, and aging.

Metabolic Investigation on the Interaction Mechanism between Dietary Dihydrochalcone Intake and Lipid Peroxidation Product Acrolein Reduction.

Acrolein (ACR), a lipid peroxidation product, pathologically participates in various chronic diseases. In vitro evidence suggestes that dietary dihydrochalcones (DHCs) potentiate safe and alternative therapeutics to synthetic pharmaceuticals for ACR scavenging. Here, to investigate whether ingested DHCs could trap ACR and thereof result in reductions in endogenous ACR in mice is aimed. Three doses of phloretin (25, 100, and 400mgkg-1 ), a major dietary DHC, are orally administrated to mice and 24h urine and fecal samples are collected, respectively. High-resolution MS-based targeted metabolomics reveal for the first time that phloretin and its oxidized metabolite are able to trap endogenous ACR via formation of ACR conjugates. Quantification further demonstrate that a) more than 13% of ingested phloretin can dose-dependently trap 0.77-9.92nmol of ACR within 24h; b) phloretin ingestion leads to marked reductions in both free ACR and ACR metabolites in mouse urine compared to control; and c) trapping reactions by phloretin can account for up to 20.1% of the total decreases in endogenous ACR, depending on the administration doses. Findings from this study indicate that regular consumption of DHCs-rich diets holds great promise to alleviate the development of ACR-associated chronic diseases.

Insulin signaling couples growth and early maturation to cholesterol intake in Drosophila

Nutrition is one of the most important influences on growth and the timing of maturational transitions including mammalian puberty and insect metamorphosis. Childhood obesity is associated with precocious puberty, but the assessment mechanism that links body fat to early maturation is unknown. During development, the intake of nutrients promotes signaling through insulin-like systems that govern the growth of cells and tissues and also regulates the timely production of the steroid hormones that initiate the juvenile-adult transition. We show here that the dietary lipid cholesterol, which is required as a component of cell membranes and as a substrate for steroid biosynthesis, also governs body growth and maturation in Drosophila via promoting the expression and release of insulin-like peptides. This nutritional input acts via the nutrient sensor TOR, which is regulated by the Niemann-Pick-type-C 1 (Npc1) cholesterol transporter, in the glia of the blood-brain barrier and cells of the adipose tissue to remotely drive systemic insulin signaling and body growth. Furthermore, increasing intracellular cholesterol levels in the steroid-producing prothoracic gland strongly promotes endoreduplication, leading to an accelerated attainment of a nutritional checkpoint that normally ensures that animals do not initiate maturation prematurely. These findings, therefore, show that a Npc1-TOR signaling system couples the sensing of the lipid cholesterol with cellular and systemic growth control and maturational timing, which may help explain both the link between cholesterol and cancer as well as the connection between body fat (obesity) and early puberty.