A high ratio of dietary n-3/n-6 polyunsaturated fatty acids improves obesity-linked inflammation and insulin resistance through suppressing activation of TLR4 in SD rats

Dietary flaxseed oil suppresses hyperglycemia and hyperinsulinemia through increasing in α-linolenic acid content in the muscle

Types of fats and oils affect the onset of lifestyle diseases. In this study, we investigated the relationship between the postprandial hyperglycemia and fatty acids content in the skeletal muscle of C57BL/6 mice given 20% lard, palm oil, corn oil, safflower oil, and flaxseed oil for 16 weeks. Lard increased plasma glucose and insulin levels at the end of feeding period, whereas flaxseed oil did not. It was noteworthy that there is a positive correlation between palmitic acid content in the muscle and postprandial hyperglycemia, and a negative correlation between α-linolenic acid content and hyperglycemia. Alternatively, mice were given 30% lard for 16 weeks. When lard was partially substituted with flaxseed oil (10-50% substitution), flaxseed oil dose-dependently prevented lard-induced hyperglycemia and hyperinsulinemia. In conclusion, flaxseed oil prevents the adverse effects of lard through increasing in α-linolenic acid content in the muscle.

Relationships of omega-3 and omega-6 polyunsaturated fatty acids with esophageal diseases: a two-sample Mendelian randomization analysis

Introduction

Omega-3 polyunsaturated fatty acids (PUFAs) have been widely studied and used as nutritional supplements because of their anti-inflammatory effects. Previous studies have shown an association between polyunsaturated fatty acids such as omega-3 and omega-6 PUFAs with the development of malignant tumors. However, the relationships of omega-3 and omega-6 PUFAs with esophageal diseases have not been characterized.

Methods

Mendelian randomization (MR) is a statistical method for identifying instrumental variables (IVs) from genome-wide association study (GWAS) data, and is associated with little confounding by environmental or other disease-related factors. We used genome-wide association study (GWAS) data from previously published studies on circulating concentrations of omega-3, omega-6, docosahexaenoic acid (DHA) and linoleic acid (LA), as well as esophageal cancer and other esophageal diseases, which were downloaded from the IEU OpenGwas database (https://gwas.mrcieu.ac.uk/) and the GWAS Catalog database (https://www.ebi.ac.uk/). The inverse variance-weighted approach was used as the principal analysis, and the MR-Egger and weighted median methods were used alongside. A series of sensitivity analyses were used to ensure the robustness of the causality estimates.

Results

We found that the circulating omega-3 PUFAs concentration was positively associated with esophageal cancer (p = 8 × 10-4), and circulating DHA concentration (the main component of omega-3 in food), was also positively associated with esophageal cancer (p = 2 × 10-2), but no significant association was found between circulating omega-6 PUFAs and esophageal cancer (p = 0.17), and circulating LA concentration (the main component of omega-6 in food), was also no significant associated with esophageal cancer (p = 0.32). We found no significant relationships of circulating omega-3 and omega-6 PUFAs concentration with four other esophageal diseases.

Conclusion

This study indicates that higher levels of circulating omega-3 PUFAs and DHA concentrations may be a risk factor for the development of esophageal cancer. Conversely, an increased omega-6/omega-3 ratio may serve as a protective factor against esophageal cancer. These findings have significant implications for the clinical application of omega-3 PUFAs and the prevention and treatment of esophageal cancer.

n-3 and n-6 Polyunsaturated Fatty Acids Modulate Macrophage-Myocyte Inflammatory Crosstalk and Improve Myocyte Insulin Sensitivity

In obesity, circulating saturated fatty acids (SFAs) and inflammatory cytokines interfere with skeletal muscle insulin signaling, leading to whole body insulin resistance. Further, obese skeletal muscle is characterized by macrophage infiltration and polarization to the inflammatory M1 phenotype, which is central to the development of local inflammation and insulin resistance. While skeletal muscle-infiltrated macrophage-myocyte crosstalk is exacerbated by SFA, the effects of other fatty acids, such as n-3 and n-6 polyunsaturated fatty acids (PUFAs), are less studied. Thus, the objective of this study was to determine the effects of long-chain n-3 and n-6 PUFAs on macrophage M1 polarization and subsequent effects on myocyte inflammation and metabolic function compared to SFA. Using an in vitro model recapitulating obese skeletal muscle cells, differentiated L6 myocytes were cultured for 24 h with RAW 264.7 macrophage-conditioned media (MCM), followed by insulin stimulation (100 nM, 20 min). MCM was generated by pre-treating macrophages for 24 h with 100 μM palmitic acid (16:0, PA-control), arachidonic acid (20:4n-6, AA), or docosahexaenoic acid (22:6n-3, DHA). Next, macrophage cultures were stimulated with a physiological dose (10 ng/mL) of lipopolysaccharide for an additional 12 h to mimic in vivo obese endotoxin levels. Compared to PA, both AA and DHA reduced mRNA expression and/or secreted protein levels of markers for M1 (TNFα, IL-6, iNOS; p < 0.05) and increased those for M2 (IL-10, TGF-β; p < 0.05) macrophage polarization. In turn, AA- and DHA-derived MCM reduced L6 myocyte-secreted cytokines (TNFα, IL-6; p < 0.05) and chemokines (MCP-1, MIP-1β; p < 0.05). Only AA-derived MCM increased L6-myocyte phosphorylation of Akt (p < 0.05), yet this was inconsistent with improved insulin signaling, as only DHA-derived MCM improved L6 myocyte glucose uptake (p < 0.05). In conclusion, dietary n-3 and n-6 PUFAs may be a useful strategy to modulate macrophage-myocyte inflammatory crosstalk and improve myocyte insulin sensitivity in obesity.

ω3-PUFA alleviates neuroinflammation by upregulating miR-107 targeting PIEZO1/NFκB p65

BACKGROUND

MiR-107 is reduced in sepsis and associated with inflammation regulation. Dietary supplementation with polyunsaturated fatty acids (ω3-PUFA) can increase the expression of miR-107; this study investigated whether the ω3-PUFA can effectively inhibit neuroinflammation and improve cognitive function by regulating miR-107 in the brain.

METHODS

The LPS-induced mouse model of neuroinflammation and the BV2 cell inflammatory model were used to evaluate the effects of ω3-PUFA on miR-107 expression and inflammation. Intraventricular injection of Agomir and Antagomir was used to modulate miR-107 expression. HE and Nissl staining for analyzing hippocampal neuronal damage, immunofluorescence analysis for glial activation, RT-qPCR, and Western blot were conducted to examine miR-107 expression and inflammation signalling.

RESULTS

The result shows that LPS successfully induced the mouse neuroinflammation model and BV2 cell inflammation model. Supplementation of ω3-PUFA effectively reduced the secretion of pro-inflammatory factors TNFα, IL1β, and IL6 induced by LPS, improved cognitive function impairment, and increased miR-107 expression in the brain. Overexpression of miR-107 in the brain inhibited the nuclear factor κB (NFκB) pro-inflammatory signalling pathway by targeting PIEZO1, thus suppressing microglial and astrocyte activation and reducing the release of inflammatory mediators, which alleviated neuroinflammatory damage and improved cognitive function in mice. miR-107, as an intron of PANK1, PANK1 is subject to PPAR α Adjust. ω3-PUFA can activate PPARα, but ω3-PUFA upregulates brain miR-107, and PPARα/PANK1-related pathways may not be synchronized, and further research is needed to confirm the specific mechanism by which ω3-PUFA upregulates miR-107.

CONCLUSION

The miR-107/PIEZO1/NFκB p65 pathway represents a novel mechanism underlying the improvement of neuroinflammation by ω3-PUFA.

The Effects of Food Nutrients and Bioactive Compounds on the Gut Microbiota: A Comprehensive Review

It is now widely recognized that gut microbiota plays a critical role not only in the development and progression of diseases, but also in its susceptibility to dietary patterns, food composition, and nutritional intake. In this comprehensive review, we have compiled the latest findings on the effects of food nutrients and bioactive compounds on the gut microbiota. The research indicates that certain components, such as unsaturated fatty acids, dietary fiber, and protein have a significant impact on the composition of bile salts and short-chain fatty acids through catabolic processes, thereby influencing the gut microbiota. Additionally, these compounds also have an effect on the ratio of Firmicutes to Bacteroides, as well as the abundance of specific species like Akkermansia muciniphila. The gut microbiota has been found to play a role in altering the absorption and metabolism of nutrients, bioactive compounds, and drugs, adding another layer of complexity to the interaction between food and gut microbiota, which often requires long-term adaptation to yield substantial outcomes. In conclusion, understanding the relationship between food compounds and gut microbiota can offer valuable insights into the potential therapeutic applications of food and dietary interventions in various diseases and health conditions.

Exploring the association between dietary Inflammatory Index and chronic pain in US adults using NHANES 1999-2004

Chronic pain, a substantial public health issue, may be influenced by dietary patterns through systemic inflammation. This cross-sectional study explored the association between Dietary Inflammatory Index (DII) and chronic pain among 2581 American adults from NHANES data. The DII, ranging from - 4.98 to 4.69, reflects the inflammatory potential of the diet, with higher scores indicating greater pro-inflammatory capacity. Our findings showed no significant association between the continuous DII score and chronic pain prevalence. However, a nonlinear relationship emerged. When the DII was categorized, a significant association between higher DII scores (DII ≥ 2.5) and chronic pain prevalence was observed. The analysis uncovered a U-shaped pattern, with an inflection point at a DII score of - 0.9, indicating an association between both low and high levels of dietary inflammation are associated with higher pain prevalence. This nuanced interaction between dietary inflammation and chronic pain indicates the possibility of incorporating dietary modification into pain management strategies and underscores the need for further research into the long-term effects of diet on chronic pain.

Growth and Hepatopancreas Health of Juvenile Chinese Mitten Crab (Eriocheir sinensis) Fed Different Levels of Black Soldier Fly (Hermetia illucens) Larvae Meal for Fish Meal Replacement

A 56-day feeding trial assessed the effects of black soldier fly larvae meal (BSFLM) on the growth performance and hepatopancreas health of juvenile Eriocheir sinensis. Six isoproteic and isolipidic diets with 0% (FM), 10% (BSFLM10), 20% (BSFLM20), 30% (BSFLM30), 40% (BSFLM40), or 50% (BSFLM50) replacement of fish meal by BSFLM were formulated. Compared to FM, replacing 10%-40% of fish meal with BSFLM did not significantly affect the weight gain rate (WGR) or specific growth rate (SGR), while BSFLM50 significantly decreased the WGR and SGR. Crabs fed BSFLM50 had significantly lower T-AOC activity than those fed other diets, and crabs fed BSFLM30, BSFLM40, or BSFLM50 had significantly lower activities of antioxidant enzymes (SOD and GSH-Px) in the hepatopancreas than those fed FM or BSFLM10. Compared to FM, BSFLM10, BSFLM20, and BSFLM30 did not affect the relative expression of genes related to the nonspecific immunity, while BSFLM40 and BSFLM50 upregulated the relative expression of these genes. Furthermore, histological analysis showed that the hepatopancreas was deformed in the BSFLM50 group, with widened lumens and loss of basal membrane integrity. In summary, BSFLM replacing 50% of fish meal reduced growth and structural damage to the hepatopancreas. An immune response was activated when the replacement level was over 30%. Therefore, the replacement level of dietary fish meal by BSFLM is recommended to be not more than 30% of the juvenile E. sinensis feed.

Dietary flaxseed oil induces production of adiponectin in visceral fat and prevents obesity in mice

Induction of obesity by dietary fats and oils differs according to the type of fat. Adiponectin is believed to be related to obesity prevention. We hypothesized that flaxseed oil is important for preventing obesity and producing adiponectin. To clarify this hypothesis, we investigated the relationship between obesity and different fat sources in mice fed diets with 6 types of fat and oils. C57BL/6J mice were given a control diet containing 5% corn oil or a high-fat diet containing 20% of either lard, palm oil, rapeseed oil, oleate-rich safflower oil, corn oil, or flaxseed oil for 14 weeks. In another experiment, mice were given a control diet and rosiglitazone (10 mg/kg body weight) by oral gavage for 1 week. At the end of study, plasma adiponectin and expression of fatty acid metabolism-related factors in white and brown adipose tissue and the liver were measured. Dietary flaxseed oil, which is rich in α-linolenic acid, did not induce obesity. Flaxseed oil resulted in increased β-oxidation-related factors in epididymal white adipose tissue, decreased fatty acid synthesis-related factors in the liver, and thermogenesis-related factor in brown adipose tissue following increase of plasma adiponectin. The results suggested that increase in plasma adiponectin after intake of flaxseed oil may be due to altered expression of AdipoQ and peroxisome proliferator-activated receptor γ in epididymal white adipose tissue. Flaxseed oil increased expression of adiponectin in visceral fat and regulated obesity-controlling fatty acid metabolism-related factors in white adipose tissue and liver, and thermogenesis-related factor in brown adipose tissue.

Association between type 2 diabetes and different types of dietary fats: A case-control study

BACKGROUND

The effect of dietary fats on type 2 diabetes (T2D) is not clear. This study aimed to determine the association between T2D and dietary fatty acids among Iranian adults.

METHODS

This case-control study was performed on 4241 participants aged 35-70, including 1804 people with T2D and pre-diabetes as the case group and 2437 people without diabetes as the control group. Dietary intake was assessed using a food frequency questionnaire (FFQ).

RESULTS

The cases had higher age (48.36 ± 8.62 vs. 54.53 ± 7.75 y, P < 0.001), weight (73.7713.41 vs. 76.18 ± 13.49 kg, P = 0.001), body mass index (BMI) (28.02 ± 4.70 vs. 24 ± 4.74 kg/m2, P = 0.001), right systolic blood pressure (RSBP) (113.33 ± 16.7 vs. 121.61 ± 17.24 mmHg, P = 0.001), right diastolic blood pressure (RDBP) (71.41 ± 10.53 vs. 75.33 ± 9.92 mmHg, P = 0.001), fasting blood sugar (FBS) (96.87 ± 19.39 vs. 169.95 ± 69.28 mg/dl, P = 0.001), blood urine nitrogen (BUN) (13.65 ± 3.74 vs. 14.26 ± 4.03 mg/dl, P = 0.001), triglyceride (TG) (141.61 ± 99.37 vs. 175.96 ± 114.74 mg/dl, P = 0.001), alkaline phosphatase (ALP) (218.24 ± 66.35 vs. 246.97 ± 72.65 IU/L, P = 0.001), low-density lipoprotein cholesterol (LDL) (111.68 ± 33.02 vs. 101.97 ± 36.54 mg/dl, P = 0.001), serum glutamic-pyruvic transaminase (SGPT) (21.88 ± 15.15 vs. 23.55 ± 15.96 IU/L, P = 0.001), gamma-glutamyl transferase (GGT) (24.66 ± 20.42 vs. 30.72 ± 30.43 IU/L P = 0.001), and cholesterol (192.45 ± 39.1190 vs. 187.12 ± 46.19 mg/dl P = 0.001) compared to the control group. T2D was negatively associated with dietary intake of PUFAs (OR = 0.93, CI95%:0.84-1.03, P = 0.01) and positively associated with dietary cholesterol (OR: 1.01, CI95%:1.001-1.01, P = 0.02).

CONCLUSION

In summary, cholesterol was positively and PUFAs were negatively associated with diabetes. If the results of the present study on the effect of fat intake on diabetes are proven, future dietary recommendations for people at risk of diabetes may be corrected by providing diets rich in polyunsaturated fatty acids and low in cholesterol.

Immunomodulatory effect of marine lipids on food allergy

Seafood is highly enriched in n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFAs), particularly eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3), in contrast to the ultra-processed foods included in the modern Western diet that have high levels of n-6 linoleic acid (LA, 18:2 n-6), precursor for the pro-inflammatory n-6 arachidonic acid (ARA, 20:4 n-6). The capacity of marine lipids to reduce plasmatic triglycerides and blood pressure have been well-described. Moreover, recent studies have also raised evidence of a potential regulatory action of marine lipids on inflammation, the immune system, and food allergy (FA). FA is considered one of the main concerns to become life threatening in food safety. The prevalence of this emerging global problem has been increasing during the last two decades, especially in industrialized countries. About a 6-8% of young children and 2-4% of adults is estimated to be affected by FA. The main objective of the current study is to update the existing knowledge, but also the limitations, on the potential impact of marine lipids and their lipid mediators in regulating immunity, inflammation, and ultimately, food allergies. In particular, the focus is on the effect of marine lipids in modulating the key factors that control the sensitization and effector phases of FA, including gut microbiota (GM), inflammation, and immune system response. Results in animal models highlight the positive effect that consuming marine lipids, whether as a supplement or through seafood consumption, may have a relevant role in improving gut dysbiosis and inflammation, and preventing or reducing the severity of FA. However, more systematic studies in humans are needed to optimize such beneficial actions to each particular FA, age, and medical condition to reach an effective clinical application of marine lipids to improve FAs and their outcomes.

Gut microbiota bridges dietary nutrients and host immunity

Dietary nutrients and the gut microbiota are increasingly recognized to cross-regulate and entrain each other, and thus affect host health and immune-mediated diseases. Here, we systematically review the current understanding linking dietary nutrients to gut microbiota-host immune interactions, emphasizing how this axis might influence host immunity in health and diseases. Of relevance, we highlight that the implications of gut microbiota-targeted dietary intervention could be harnessed in orchestrating a spectrum of immune-associated diseases.

Potential associations between organic dairy products, gut microbiome, and gut health: A review

Organic products have received longstanding, widespread attention for their nutritional and ecological benefits, as they are said to have certain positive health attributes and contain fewer harmful compounds than conventional (or non-organic) products. We reviewed the recent literature to examine potential associations between nutrient composition, gut microbiota, and gut health effects in recent comparative studies of organic and conventional dairy products. Trends of increased ratios of omega-3 to omega-6 polyunsaturated fatty acids and unsaturated to saturated fat, increased fat-soluble vitamin content, and decreased levels of certain pernicious contaminants in organic milk were observed across the studies reviewed. Studies of the metabolism of these nutrients in both in vitro and in vivo settings, and their or their metabolites' interaction with the intestinal epithelium show that nutrients enriched in organic dairy products may support host nutrient uptake and mediate gut inflammation. Research on the effects of single food products or classes of food products on gut health is rare. The extent of these benefits is highly likely to be mediated by both the magnitude of the difference in nutrient types and quantities, and by dietary intake levels of dairy products. Intervention studies directly examining the different effects of organic and conventional dairy products on gut health in humans are needed to further elucidate this relationship.

Effects of dietary adjustment of n-3:n-6 fatty-acid ratio to 1:2 on anti-inflammatory and insulin-signaling pathways in ovariectomized mice with high fat diet-induced obesity

Estrogen deficiency increases the secretion of inflammatory mediators and can lead to obesity. Consequently, estrogen deficiency can cause metabolic syndrome, particularly insulin resistance during menopause. Both fish oil and perilla oil contain n-3 fatty acids, which may regulate several inflammatory cytokines. Additionally, adjusting the dietary n-3:n-6 fatty-acid ratio to 1:2 may help treat or prevent chronic diseases. Therefore, we investigated the effect of anti-inflammatory and insulin-signaling pathways, not solely in relation to the (n-3:n-6 fatty-acid ratio at 1:2), but also considering the origin of n-3 fatty acids found in fish oil and perilla oil, in a mouse model of estrogen deficiency induced by ovariectomy and obesity induced by a high-fat diet (HFD). Female C57BL/6J mice were divided into five groups: sham mice on a normal diet; ovariectomized (OVX) mice on a normal diet (OC); OVX mice on a HFD plus lard oil (OL), fish oil (OF), or perilla oil (OP). The dietary n-3:n-6 ratio in the OF and OP groups was adjusted to 1:2. The results showed OF group exhibited significantly lower abdominal adipose tissue weight, fewer liver lipid droplets, and smaller uterine adipocytes, compared with the OL group. Compared with the OL group, the OF and OP groups exhibited higher oral glucose tolerance and lower serum alanine aminotransferase activity, triacylglycerol levels, and total cholesterol levels. Hepatic JAK2, STAT3, and SOCS3 mRNA expression and p-NF-κB p65 and IL-6 levels were significantly lower in the OF and OP groups than in the OL group. Only the OF group exhibited an increase in PI3K and Akt mRNA expression, decrease in GLUT2 mRNA expression, and considerable elevation of p-Akt. Both fish and perilla oil reduced inflammatory signaling markers. However, only fish oil improved insulin signaling (PI3K, Akt, and GLUT2). Our data suggest that fish oil can alleviate insulin signaling through activating the PI3K-Akt-GLUT2 cascade signaling pathway.

The degree of food processing can influence serum fatty acid and lipid profiles in women with severe obesity

Background

The increase in the prevalence of obesity is associated with the increase in the consumption of ultra-processed foods and may be related to the increase in the disorders involving metabolism and the transport and storage of fatty acids.

Objective

To evaluate the effect of processed food consumption according to the degree of processing on the serum fatty acid levels and lipid profile of women with severe obesity.

Methods

This was a cross-sectional study. Data were collected from anthropometric assessments, the food frequency questionnaire (FFQ), and blood tests for lipidogram studies and serum fatty acid measurements. The foods consumed were identified through the FFQ and classified according to the degree of processing based on the NOVA rating, and the frequencies of consumption were transformed into scores, as proposed by Fornés methodology. Data were analyzed using IBM SPSS Statistics, version 21. The significance level for the analysis was set at 5%.

Results

This study included 44 women with a mean age of 40.59 years and mean body mass index of 48.61 kg/m2. An inverse association was observed between the consumption of unprocessed and the occurrence of hypertriglyceridemia (p = 0.021) and levels of triglycerides (p = 0.047), total cholesterol (p = 0.030), and very low-density lipoprotein-cholesterol (p = 0.039). The consumption of processed foods was positively associated with the presence of hypertriglyceridemia (p = 0.044) and omega 6/3 ratio (p = 0.001) and negatively associated with total omega 3 levels (p = 0.011). The consumption of processed foods was positively associated with total cholesterol (p = 0.041) and negatively associated with the omega 3/6 ratio (p = 0.001). A negative correlation was found between the average consumption of ultra-processed foods (at least once a week) and serum level of high-density lipoprotein (p = 0.035).

Conclusion

The consumption of processed and ultra-processed foods was associated with unfavorable lipid profiles and fatty acid levels in women with severe obesity. These results emphasize the importance of promoting the consumption of unprocessed food to mitigate metabolic disorders linked to processed food intake.

Dietary n-3/n-6 polyunsaturated fatty acid ratio modulates growth performance in spotted seabass (Lateolabrax maculatus) through regulating lipid metabolism, hepatic antioxidant capacity and intestinal health

An 8-week feeding experiment was carried out to explore the effects of dietary n-3/n-6 polyunsaturated fatty acid (PUFA) ratio on growth performance, lipid metabolism, hepatic antioxidant status, and gut flora of spotted seabass (Lateolabrax maculatus). Six experimental diets were formulated to contain different levels of two purified oil sources including docosahexaenoic and eicosapentaenoic acids enriched oil (n-3) and linoleic acid-enriched oil (n-6) leading to n-3/n-6 PUFA ratios of 0.04, 0.35, 0.66, 1.35, 2.45 and 16.17. Each diet was fed to triplicate groups of juvenile L. maculatus (11.06 ± 0.20 g, 30 fish/tank). Final body weight (FBW), weight gain (WG), specific growth rates (SGR), protein efficiency ratio (PER) and feed utilization efficiency increased as n-3/n-6 PUFA ratio increased up to a certain level, and then decreased thereafter. Fish fed the diet with n-3/n-6 PUFA ratio of 0.66 exhibited the highest FBW, WG, SGR and PER and the lowest feed conversion ratio. Lower n-3/n-6 PUFA ratios induced up-regulated expression of lipid synthesis-related genes (fas, acc2 and srebp-1c) and down-regulated expression of lipolysis related genes (atgl, pparα, cpt-1 and aox). Higher expression of lipolysis-related genes (atgl, pparα and cpt-1) was recorded at moderate n-3/n-6 PUFA ratios (0.66 to 1.35). Moreover, inappropriate n-3/n-6 PUFA ratios triggered up-regulation of pro-inflammatory genes (il-6 and tnf-α) and down-regulation of anti-inflammatory genes (il-4 and il-10) in the intestine. The diet with n-3/n-6 PUFA ratio of 0.66 inhibited intestine inflammation, improved intestinal flora richness, increased the abundance of beneficial bacteria such as Lactobacillus, Alloprevotella and Ruminococcus, and reduced the abundance of harmful bacteria including Escherichia-Shigella and Enterococcus. In summary, it could be suggested that a dietary n-3/n-6 PUFA ratio of 0.66 can improve growth performance and feed utilization in L. maculatus, as is deemed to be mediated through regulation of lipid metabolism and intestinal flora.

Does Dietary Polyunsaturated Fatty Acid Intake Associate With Bone Mineral Density and Limb Structural Changes in Early Rheumatoid Arthritis?

Background

Rheumatoid arthritis (RA) is an inflammatory disease that can result in bone erosion, lean mass lowering, and increase of fat mass without changes in body weight. The dietary consumption of polyunsaturated fatty acids (PUFAs) has been assessed in many studies due to their potential anti-inflammatory effect.

Aim

The aim of this research was to identify if dietary intake of PUFAs associates with bone mineral density (BMD) and limb structural changes in early rheumatoid arthritis (ERA) compared to a population-based control group. The study was conducted because previous results have been insufficient.

Methods

The study group consisted of 83 ERA patients and 321 control subjects. A dual-energy X-Ray absorptiometry (DXA) machine was used to measure hip, lumbar spine, and radius BMD, as well as arm and leg fat, lean, and bone mass. Dietary habits and inflammatory markers were assessed to evaluate the effects to BMD and limb structural changes.

Results

In ERA subjects, higher dietary consumption of PUFAs was associated with a decrease in arm fat mass (b -28.17, P = .02) and possibly with higher lumbar BMD (b 0.008, P = .058). Limb bone and lean mass changes were not associated with dietary intake of PUFAs.

Conclusion

Balanced nutrition is essential. Consuming PUFAs could be beneficial in ERA preventing structural changes to hands, but additional research is needed.

Partial replacement of high-fat diet with n-3 PUFAs enhanced beef tallow attenuates dyslipidemia and endoplasmic reticulum stress in tunicamycin-injected rats

Introduction

Metabolic syndrome (MetS) is considered as a complex, intertwined multiple risk factors that directly increase the risk of various metabolic diseases, especially cardiovascular atherosclerotic diseases and diabetes mellitus type 2. While lifestyle changes, including dietary intervention are effective in mitigating or preventing MetS, there are no specific therapies against MetS. Typical western diets comprise of high saturated fatty acid, cholesterol, and simple sugar; consequently their consumption may increase the potential pathological developmental risk of MetS. Partial replacement of dietary fatty acids with polyunsaturated fatty acids (PUFAs) is widely recommended measure to manage MetS-related disorders.

Methods

In the present study, we used rat model to investigate the role of n-3 PUFA enriched beef tallows (BT) on MetS and tunicamycin (TM)-induced endoplasmic reticulum (ER) stress, by partially replacing dietary fat (lard) with equal amounts of two different BTs; regular BT or n-3 PUFA-enriched BT. The experimental rats were randomly assigned to three different dietary groups (n = 16 per group): (1) high-fat and high-cholesterol diet (HFCD); (2) HFCD partially replaced with regular BT (HFCD + BT1); (3) HFCD partially replaced with n-3 enhanced BT (w/w) (HFCD + BT2). After 10 weeks of dietary intervention, each experimental rodent was intraperitoneally injected with either phosphate-buffered saline or 1 mg/kg body weight of TM.

Results

HFCD + BT2 showed improved dyslipidemia before TM injection, and increased serum high-density lipoprotein cholesterol (HDL-C) levels after TM injection. BT replacement groups had significantly reduced hepatic triglyceride (TG) levels, and decreased total cholesterol (TC) and TG levels in epididymal adipose tissue (EAT). Furthermore, BT replacement remarkably attenuated TM-induced unfolded protein responses (UPRs) in liver, showing reduced ER stress, with BT2 being more effective in the EAT.

Discussion

Therefore, our findings suggest that partially replacing dietary fats with n-3 PUFA to lower the ratio of n-6/n-3 PUFAs is beneficial in preventing pathological features of MetS by alleviating HFCD- and/or TM-induced dyslipidemia and ER stress.

Sustained release resolvin D1 liposomes are effective in the treatment of osteoarthritis in obese mice

Osteoarthritis (OA) is the most common joint disorder and currently affects >500 million patients worldwide, with ~60% of them also suffering from obesity. There is no drug approved for human use that changes the course of OA progression. OA is one of the most common comorbidities of obesity, and obesity-related OA (ObOA) is a serious health concern because it shows heightened severity of tissue damage and also predominantly affects the working population. Unresolved inflammation is a major driver of ObOA, thus, resolving disease-associated inflammation is a viable strategy to treat ObOA. Resolvins are highly potent molecules that play a role in the resolution of inflammation and promote tissue healing. However, small molecules (like Resolvin D1; RvD1) have to be administered frequently or prior to injury because they lose their in vivo activity rapidly either by lymphatic clearance, or oxidation-mediated deactivation. In this study, we have encapsulated RvD1 in liposomes and established its efficacy in the mouse model of ObOA at much lower dosages than freely administered RvD1. Liposomal RvD1 (lipo-RvD1) acted as a source of the RvD1 molecules for ~11 days in vitro in synovial fluid derived from patients. When administered prophylactically or therapeutically, lipo-RvD1 suppressed cartilage damage in male C57BL/6 mice compared to untreated and free RvD1 treatments. This efficacy was achieved by increasing the proportion of the proresolution M2 macrophages over proinflammatory M1 macrophages in the synovial membrane. These results show the potential of lipo-RvD1 as an anti-OA agent.

Lipidomics in gestational diabetes mellitus

PURPOSE OF REVIEW

Epidemiological and mechanistic studies have reported relationships between blood lipids, mostly measured by traditional method in clinical settings, and gestational diabetes mellitus (GDM). Recent advances of high-throughput lipidomics techniques have made available more comprehensive lipid profiling in biological samples. This review aims to summarize evidence from prospective studies in assessing relations between blood lipids and GDM, and discuss potential underlying mechanisms.

RECENT FINDINGS

Mass spectrometry and nuclear magnetic resonance spectroscopy-based analytical platforms are extensively used in lipidomics research. Epidemiological studies have identified multiple novel lipidomic biomarkers that are associated with risk of GDM, such as certain types of fatty acids, glycerolipids, glycerophospholipids, sphingolipids, cholesterol, and lipoproteins. However, the findings are inconclusive mainly due to the heterogeneities in study populations, sample sizes, and analytical platforms. Mechanistic evidence indicates that abnormal lipid metabolism may be involved in the pathogenesis of GDM by impairing pancreatic β-cells and inducing insulin resistance through several etiologic pathways, such as inflammation and oxidative stress.

SUMMARY

Lipidomics is a powerful tool to study pathogenesis and biomarkers for GDM. Lipidomic biomarkers and pathways could help to identify women at high risk for GDM and could be potential targets for early prevention and intervention of GDM.

n-3 polyunsaturated fatty acids improve depression-like behavior by inhibiting hippocampal neuroinflammation in mice via reducing TLR4 expression

INTRODUCTION

n-3 polyunsaturated fatty acids (PUFAs) are believed to be implicated in the pathogenesis of many inflammation-related diseases, including depression.

METHODS

The mouse model of depression was established through chronic unpredictable mild stress (CUMS), the mice were intervened with n-3 PUFAs, and then the expression of toll-like receptor 4 (TLR4) was stimulated with lipopolysaccharides (LPS). Tail suspension test (TST), forced swimming test (FST) and sucrose preference test were performed to monitor the depression behavior of mice. Microglia activation was detected by Iba1 immunofluorescence, and neuronal injury was detected by Nissl staining. Concentrations of tumor necrosis factor (TNF)-α, Interleukin (IL)-6 and IL-1β in the hippocampus were assessed via enzyme linked immunosorbent assay (ELISA). Quantitative real time polymerase chain reaction was used to detect IL-6, IL-1β and TNF-α messenger RNA levels. Western blot was utilized for detection of TLR4 protein expression.

RESULTS

CUMS significantly reduced the sucrose preference in mice, while increased the immobility time in FST and TST. Moreover, CUMS significantly aggravated microglia activation and neuronal damage in mice and increased the levels of IL-6, IL-1β and TNF-α in hippocampal tissues, however, intervention with n-3 PUFAs could improve the above effects. Further, the increased TLR4 induced by LPS partially reversed the inhibition of n-3 PUFAs on depression-like behaviors, microglial activation and inflammatory injury of hippocampal neurons.

CONCLUSION

n-3 PUFAs may ameliorate depression-like behaviors via reducing hippocampal neuroinflammation in CUMS-induced mice by regulating TLR4 expression, suggesting that n-3 PUFAs may be an effective antidepressant, which provides evidence for future treatment of depression.

Food and Gut Microbiota-Derived Metabolites in Nonalcoholic Fatty Liver Disease

Diet and lifestyle are crucial factors that influence the susceptibility of humans to nonalcoholic fatty liver disease (NAFLD). Personalized diet patterns chronically affect the composition and activity of microbiota in the human gut; consequently, nutrition-related dysbiosis exacerbates NAFLD via the gut–liver axis. Recent advances in diagnostic technology for gut microbes and microbiota-derived metabolites have led to advances in the diagnosis, treatment, and prognosis of NAFLD. Microbiota-derived metabolites, including tryptophan, short-chain fatty acid, fat, fructose, or bile acid, regulate the pathophysiology of NAFLD. The microbiota metabolize nutrients, and metabolites are closely related to the development of NAFLD. In this review, we discuss the influence of nutrients, gut microbes, their corresponding metabolites, and metabolism in the pathogenesis of NAFLD.

Reprogramming Metabolism of Macrophages as a Target for Kidney Dysfunction Treatment in Autoimmune Diseases

Chronic kidney disease (CKD), as one of the main complications of many autoimmune diseases, is difficult to cure, which places a huge burden on patients’ health and the economy and poses a great threat to human health. At present, the mainstream view is that autoimmune diseases are a series of diseases and complications caused by immune cell dysfunction leading to the attack of an organism’s tissues by its immune cells. The kidney is the organ most seriously affected by autoimmune diseases as it has a very close relationship with immune cells. With the development of an in-depth understanding of cell metabolism in recent years, an increasing number of scientists have discovered the metabolic changes in immune cells in the process of disease development, and we have a clearer understanding of the characteristics of the metabolic changes in immune cells. This suggests that the regulation of immune cell metabolism provides a new direction for the treatment and prevention of kidney damage caused by autoimmune diseases. Macrophages are important immune cells and are a double-edged sword in the repair process of kidney injury. Although they can repair damaged kidney tissue, over-repair will also lead to the loss of renal structural reconstruction function. In this review, from the perspective of metabolism, the metabolic characteristics of macrophages in the process of renal injury induced by autoimmune diseases are described, and the metabolites that can regulate the function of macrophages are summarized. We believe that treating macrophage metabolism as a target can provide new ideas for the treatment of the renal injury caused by autoimmune diseases.

Partial Replacement of High-Fat Diet with Beef Tallow Attenuates Dyslipidemia and Endoplasmic Reticulum Stress in db/db Mice

High-fat diet (HFD) consumption is closely associated with an increased risk of metabolic syndromes (MetS), such as obesity, type 2 diabetes, and cardiovascular diseases (CVDs). Therefore, the consumption of alternative and functional fatty acids to replace saturated fatty acids and/or trans-fatty acids with polyunsaturated fatty acids has become an important dietary strategy for the prevention of MetS. Consumption of omega-3 fatty acids (n-3) reduces various physiological complications, including CVDs, nonalcoholic fatty liver disease, and insulin resistance, related to inflammatory responses. In this study, we investigated the partial replacement effects of HFD with beef tallow (BT) on dyslipidemia and endoplasmic reticulum (ER) stress in male db/db mice. The animals were grouped to one of four dietary intervention groups (n = 16 per group): (1) normal diet, (2) HFD, (3) HFD partially replaced with regular beef tallow (HFD+BT1), or (4) HFD partially replaced with beef tallow containing a relatively reduced omega-6 fatty acid (n-6)/n-3 ratio (HFD+BT2) than HFD+BT1. After 6 weeks of dietary intervention, 1 mg/kg of phosphate-buffered saline or tunicamycin (TM) was injected intraperitoneally. HFD+BT2 significantly suppressed the serum total cholesterol and non-high-density lipoprotein cholesterol levels more than HFD and HFD+BT1, and triglyceride levels in the epididymal adipose tissue (EAT) were remarkably decreased. Mice that received HFD+BT2 had elevated protein expressions of phospho-AMP-activated protein kinase (p-AMPK). Moreover, HFD+BT2 effectively inhibited ER stress in the liver and EAT. Consistent with our hypothesis, HFD+BT2 remarkably alleviated dyslipidemia and TM-inducible ER stress, while activating p-AMPK.

Dietary Fatty Acid Regulation of the NLRP3 Inflammasome via the TLR4/NF-κB Signaling Pathway Affects Chondrocyte Pyroptosis

Dietary fatty acid (FA) content and type have different effects on obesity-associated osteoarthritis (OA), but the mechanisms underlying these differences are not fully understood. Inflammation activated by toll-like receptor 4 (TLR4)/nuclear factor- (NF-) κB signaling and pyroptosis induced by the NLRP3/caspase-1/gasdermin D (GSDMD) signaling pathway play important roles in OA development. Our aim in this study was to observe the effects of dietary FAs on the articular cartilage of obese post-traumatic OA model mice and on chondrocytes stimulated by lipopolysaccharide (LPS) and to determine whether the underlying mechanisms involve TLR4/NF-κB and NLRP3/caspase-1/GSDMD signaling pathways. Mice were fed high-fat diets rich in various FAs and underwent surgical destabilization of the medial meniscus to establish the obesity-related post-traumatic OA model. LPS-induced SW1353 chondrosarcoma cells were used to mimic OA status in vitro, and TLR4 inhibitors or TLR4 overexpressing lentivirus was administered. Analysis using weight-matched mice and multiple regression models revealed that OA was associated with dietary FA content and serum inflammatory factor levels, but not body weight. Diets rich in n-3 polyunsaturated fatty acids (PUFAs) attenuated OA and inhibited the TLR4/NF-κB and NLRP3/caspase-1/GSDMD signaling pathways, whereas diets rich in saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), or n-6 PUFAs increased OA severity and activated these pathways. In vitro results for SFAs, n-6 PUFAs, and n-3 PUFAs were consistent with the animal experiments. However, those for MUFAs were not. FA effects on the NLRP3/caspase-1/GSDMD pathway were associated with the inhibition or activation of the TLR4 signaling pathway. In conclusion, diets rich in SFAs or n-6 PUFAs can exacerbate obesity-associated OA, whereas those rich in n-3 PUFAs have protective effects against this disease, due to their respective pro-/anti-inflammatory and pyroptotic effects. Further research on dietary FA supplements as a potential therapeutic approach for OA is needed.

Effects of in ovo feeding of t10,c12-conjugated linoleic acid on hepatic lipid metabolism and subcutaneous adipose tissue deposition in newly hatched broiler chicks

The purpose of this study was to investigate whether in ovo feeding of t10,c12-conjugated linoleic acid (CLA) could regulate hepatic lipid metabolism and decrease lipid accumulation in newly hatched chicks. Three hundred and sixty fertilely specific pathogen-free hatching eggs were selected and randomly divided into 6 groups. On embryonic day 11 of incubation (E11), 0, 1.5, 3.0, 4.5, 6.0, or 7.5 mg t10,c12-CLA were injected into the eggs. The results indicated that in ovo feeding of t10,c12-CLA significantly decreased the subcutaneous adipose tissue (SAT) mass and the relative SAT weight of newly hatched chicks in linear and quadratic manners (P < 0.05). In liver, the levels of triglycerides were reduced linearly and quadratically and total cholesterol were reduced quadratically as the dose of t10,c12-CLA increased (P < 0.05). Meanwhile, the hepatic carnitine palmitoyltransferase-1a (CPT1a) content and polyunsaturated fatty acid proportion were increased quadratically in t10,c12-CLA groups (P < 0.05), accompanied by the decrease of malondialdehyde level and the increase of glutathione peroxidase and total antioxidant capacity activities (P < 0.05). In addition, in ovo feeding of t10,c12-CLA decreased the mRNA expression levels of fatty acid synthase, acetyl-CoA carboxylase 1 in linear and quadratic manners (P < 0.05), and decreased the mRNA expression of adipose triacylglyceride lipase and stearoyl-CoA desaturase significantly in liver (P < 0.05), accompanied by upregulating the mRNA expression of CPT1a quadratically and AMP-activated protein kinase α linearly and quadratically (P < 0.05). In SAT, the mRNA expression of peroxisome proliferator-activated receptor γ (PPARγ) and sterol regulatory element-binding protein-1c were decreased linearly and quadratically (P < 0.05), and the expression of PPARα and CPT1a genes were increased linearly and quadratically as the dose of t10,c12-CLA increased (P < 0.05). In conclusion, our findings demonstrate that in ovo feeding of t10,c12-CLA alleviates lipid accumulation in newly hatched chicks by suppressing fatty acid synthesis and stimulating lipolysis in the liver and inhibiting adipocyte differentiation in subcutaneous adipose tissue.

Effect of different dietary fats on inflammation and glucose intolerance in high fructose and high fat fed experimental animals

Objectives

Diet is the major modifiable risk factor for the onset of insulin resistance and its progression into diabetes. In the present study the effect of various dietary fats on inflammatory homeostasis and glucose tolerance is investigated in high fat and high fructose fed mice model.

Methods

C57/BL6J mice were divided into four groups and fed a casein-based diet containing high fructose (45%) and high fat (24%) (clarified butter oil [CBO]; safflower oil [SFFO] and lard oil [LO]) for 120 days; oral glucose tolerance (OGTT), plasma lipid profile and plasma & adipose tissue cytokines levels were compared with the control diet (10% groundnut oil and 59.5% starch) fed animals.

Results

The total cholesterol and triglycerides were higher in CBO and LO fed animals with glucose intolerance and increased body weights; liver and white adipose tissue weights were higher in CBO and LO fed animals respectively. CBO feeding increased the plasma (IFN-γ) and adipose tissue cytokines (IFN-γ, IL-10, IL-6 & TNF-α). LO feeding increased plasma IFN-γ, TNF-α and IL-1β and adipose tissue IL-6. SFFO feeding decreased body weight and tissue cytokines and increased plasma IFN-γ levels without causing impairment in the glucose tolerance.

Conclusions

Consumption of a high fructose and high fat diet which mimic the present-day dietary pattern resulted in altered inflammatory homeostasis and impairment in glucose tolerance in 24% CBO and LO fed animals. The deleterious effects of high fructose feeding were reversed in SFFO fed mice possibly due to the presence of oleic and linoleic acids.

Pathophysiological Commonality Between Irritable Bowel Syndrome and Metabolic Syndrome: Role of Corticotropin-releasing Factor-Toll-like Receptor 4-Proinflammatory Cytokine Signaling

Irritable bowel syndrome (IBS) displays chronic abdominal pain with altered defecation. Most of the patients develop visceral hypersensitivity possibly resulting from impaired gut barrier and altered gut microbiota. We previously demonstrated that colonic hyperpermeability with visceral hypersensitivity in animal IBS models, which is mediated via corticotropin-releasing factor (CRF)-Toll-like receptor 4 (TLR4)-proinflammatory cytokine signaling. CRF impairs gut barrier via TLR4. Leaky gut induces bacterial translocation resulting in dysbiosis, and increases lipopolysaccharide (LPS). Activation of TLR4 by LPS increases the production of proinflammatory cytokines, which activate visceral sensory neurons to induce visceral hypersensitivity. LPS also activates CRF receptors to further increase gut permeability. Metabolic syndrome (MS) is a cluster of cardiovascular risk factors, including insulin resistance, obesity, dyslipidemia, and hypertension, and recently several researchers suggest the possibility that impaired gut barrier and dysbiosis with low-grade systemic inflammation are involved in MS. Moreover, TLR4-proinflammatory cytokine contributes to the development of insulin resistance and obesity. Thus, the existence of pathophysiological commonality between IBS and MS is expected. This review discusses the potential mechanisms of IBS and MS with reference to gut barrier and microbiota, and explores the possibility of existence of pathophysiological link between these diseases with a focus on CRF, TLR4, and proinflammatory cytokine signaling. We also review epidemiological data supporting this possibility, and discuss the potential of therapeutic application of the drugs used for MS to IBS treatment. This notion may pave the way for exploring novel therapeutic approaches for these disorders.

Nutritional Influences on Locomotive Syndrome

Healthy dietary habits are important to prevent locomotive syndrome (LS). We investigated the relationship between LS and nutritional intake using community health checkup data. We included 368 participants who underwent LS staging, blood sampling, and nutritional intake assessments. Participants (163 adults < 65: 205 older adults ≥ 65) were divided into normal (N; LS stage 0) and LS (L; LS stage 1–2) groups, and blood sample data and nutritional intake were compared between groups. Among adults (N group, 71; L group, 92), low-density lipoprotein cholesterol (LDL-C) was significantly lower, and Vitamin B₁ intake was significantly higher in the L than in the N group; LDL-C, p = 0.033; Vitamin B1, 0.029. Among older adults (N group, 85; L group, 120), hemoglobin (Hb), albumin, and calcium levels were significantly lower, and sodium, monounsaturated fatty acids (MUFA), and n-6 polyunsaturated fatty acids (n-6 PUFA) were significantly higher in the L than the N group; Hb, p = 0.036; albumin, 0.030; calcium, 0.025; sodium; 0.029; MUFA; 0.047, n-6 PUFA; 0.0233). Logistic regression analysis indicated that sodium was the risk factor for the L group (exp (B) 1.001, 95% CI: 1–1.001, p = 0.032). In conclusion, salt intake was associated with LS.

Polyphenols and ω-3 PUFAs: Beneficial Outcomes to Obesity and Its Related Metabolic Diseases

Obesity is associated with the leading causes of death in the worldwide. On the other hand, the intake of vegetables, fruits and fish is related to the reduction of obesity and other metabolic syndromes. This review aims to highlight the role of ingestion of polyphenols and omega-3 polyunsaturated fatty acids (ω-3 PUFAs) in reducing obesity and related metabolic diseases (RMDs). The consumption of vegetables, fish and by-products rich in polyphenols and α-linolenic acid (ALA), as well as oils rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are associated with a decrease in obesity and its RMDs in consumers. Furthermore, we discussed the adequate amount of extracts, powder, polyphenols, ω-3 PUFAs administrated in animal models and human subjects, and the relevant outcomes obtained. Thus, we appeal to the research institutions and departments of the Ministries of Health in each country to develop a food education joint project to help schools, businesses and families with the aim of reducing obesity and other metabolic diseases.

Intestinal Microbiota as a Contributor to Chronic Inflammation and Its Potential Modifications

The gut microbiota is a crucial factor in maintaining homeostasis. The presence of commensal microorganisms leads to the stimulation of the immune system and its maturation. In turn, dysbiosis with an impaired intestinal barrier leads to accelerated contact of microbiota with the host’s immune cells. Microbial structural parts, i.e., pathogen-associated molecular patterns (PAMPs), such as flagellin (FLG), peptidoglycan (PGN), lipoteichoic acid (LTA), and lipopolysaccharide (LPS), induce inflammation via activation of pattern recognition receptors. Microbial metabolites can also develop chronic low-grade inflammation, which is the cause of many metabolic diseases. This article aims to systematize information on the influence of microbiota on chronic inflammation and the benefits of microbiota modification through dietary changes, prebiotics, and probiotic intake. Scientific research indicates that the modification of the microbiota in various disease states can reduce inflammation and improve the metabolic profile. However, since there is no pattern for a healthy microbiota, there is no optimal way to modify it. The methods of influencing microbiota should be adapted to the type of dysbiosis. Although there are studies on the microbiota and its effects on inflammation, this subject is still relatively unknown, and more research is needed in this area.

Maternal C-Peptide and Insulin Sensitivity, but Not BMI, Associate with Fatty Acids in the First Trimester of Pregnancy

Maternal obesity in pregnancy is a pro-inflammatory condition exposing the fetus to an adverse environment. Here, we tested associations of maternal obesity (primary exposures: BMI, leptin) and metabolic parameters (secondary exposures: glucose, C-peptide, and insulin sensitivity) with total serum concentrations of fatty acids in the first trimester of human pregnancy. This cross-sectional study included 123 non-smoking women with singleton pregnancy. In maternal serum, cotinine, leptin, and C-peptide (ELISA), glucose (hexokinase-based test) and fatty acids (gas chromatography) were quantified, and the insulin sensitivity index (ISHOMA) was calculated. Concentrations of fatty acid classes and total fatty acids did not differ between BMI or leptin categories. However, n-3 polyunsaturated fatty acids (PUFA) were decreased in the category with the highest C-peptide concentration (n-3 PUFA: CI -35.82--6.28, p < 0.006) and in the lowest ISHOMA category (n-3 PUFA: CI -36.48--5.61, p < 0.008). In a subcohort, in which fetal sex was determined (RT-qPCR of placental tissue), C-peptide was significantly associated with docosahexaenoic acid (DHA) in mothers bearing a female (n = 46), but not male (n = 37) fetus. In conclusion, pregnant women with high fasting C-peptide and low ISHOMA had decreased n-3 PUFA, and DHA was lower with higher C-peptide only in mothers bearing a female fetus.

Perilla Seed Oil Alleviates Gut Dysbiosis, Intestinal Inflammation and Metabolic Disturbance in Obese-Insulin-Resistant Rats

Background: High-fat diet (HFD) consumption induced gut dysbiosis, inflammation, obese-insulin resistance. Perilla seed oil (PSO) is a rich source of omega-3 polyunsaturated fatty acids with health promotional effects. However, the effects of PSO on gut microbiota/inflammation and metabolic disturbance in HFD-induced obesity have not been investigated. Therefore, we aimed to compare the effects of different doses of PSO and metformin on gut microbiota/inflammation, and metabolic parameters in HFD-fed rats. Methods: Thirty-six male Wistar rats were fed either a normal diet or an HFD for 24 weeks. At week 13, HFD-fed rats received either 50, 100, and 500 mg/kg/day of PSO or 300 mg/kg/day metformin for 12 weeks. After 24 weeks, the metabolic parameters, gut microbiota, gut barrier, inflammation, and oxidative stress were determined. Results: HFD-fed rats showed gut dysbiosis, gut barrier disruption with inflammation, increased oxidative stress, metabolic endotoxemia, and insulin resistance. Treatment with PSO and metformin not only effectively attenuated gut dysbiosis, but also improved gut barrier integrity and decreased gut inflammation. PSO also decreased oxidative stress, metabolic endotoxemia, and insulin resistance in HFD-fed rats. Metformin had greater benefits than PSO. Conclusion: PSO and metformin had the beneficial effect on attenuating gut inflammation and metabolic disturbance in obese-insulin resistance.

Associations Between Erythrocyte Membrane Fatty Acid Compositions and Biomarkers of Vascular Health in Adults With Type 1 Diabetes With and Without Insulin Resistance: A Cross-Sectional Analysis

OBJECTIVES

The aim of this study was to assess the relationship between specific erythrocyte fatty acid levels and vascular health in type 1 diabetes (T1D) with and without insulin resistance (IR).

METHODS

We analyzed baseline pretreatment data in a subset of 23 patients with T1D from a previously published randomized controlled trial consisting of comprehensive erythrocyte-derived fatty acid profiles and a panel of inflammation-associated endothelial markers. Estimated glucose disposal rate was used to identify and categorize patients with IR. We utilized principal component analysis (PCA) to cluster vascular biomarkers to compute a single "vascular signal" and utilized univariate linear regression models to investigate the association with IR and fatty acid profiles.

RESULTS

Subjects with IR displayed significantly higher levels of linoleic acid (p=0.001), lower levels of eicosapentaenoic acid (EPA) (p<0.001), lower levels of omega-3 polyunsaturated fatty acid (n-3PUFA) (p<0.006) and an increased omega-6 (n-6)PUFA:n-3PUFA ratio (p=0.001). IR was associated with significantly higher linoleic acid levels, total n-6PUFA and an increased ratio of n-6PUFA:n-3PUFA, and negatively associated with arachidonic acid and EPA levels, total saturated fatty acid and total n-3PUFA. The PCA-derived vascular biomarker cluster was positively associated with linoleic acid and n-6PUFA:n-3PUFA ratio, and inversely associated with EPA.

CONCLUSIONS

Specific erythrocyte membrane fatty acid compositions are associated with impaired vascular health and IR in adults with T1D. These findings suggest that IR and risk of associated complications may be influenced by specific fatty acid profiles, and thus potentially modified by the selective targeting of dietary fatty acids.

MyD88 determines the protective effects of fish oil and perilla oil against metabolic disorders and inflammation in adipose tissue from mice fed a high-fat diet

BACKGROUND

The beneficial effects of ω-3 polyunsaturated fatty acids (PUFA) vary between different sources. However, there is a paucity of comparative studies regarding the effects and mechanisms of marine and plant ω-3 PUFA on obesity.

OBJECTIVE

The aim of this study was to evaluate the effects of fish oil (FO) and perilla oil (PO) on glucolipid metabolism, inflammation, and adipokine in mice fed a high-fat (HF) diet in association with the contribution of toll-like receptor 4 (TLR4)/myeloid differentiation primary response 88 (MyD88) pathway.

METHODS

C57BL/6J mice and MyD88-/- mice were randomly divided into 4 groups: normal chow diet, HF diet, HF diet accompanied by daily gavage with either FO or PO. After 4 weeks, blood biochemistries, adipocyte histology, mRNA, and protein expression of MyD88-dependent and -independent pathways of TLR4 signaling in epididymal adipose tissue were measured.

RESULTS

In C57BL/6J mice, there were no statistical differences between FO and PO in decreasing body weight, glucose, insulin, triglyceride, total cholesterol, interleukin-6, and increasing adipocyte counts. FO and PO decreased mRNA and protein expression of TLR4, MyD88, tumor necrosis factor receptor-associated factor 6, inhibitor of nuclear factor kappa B kinase beta and nuclear factor-kappa B p65. In MyD88-/- mice, the beneficial effects of FO and PO on HF diet-induced metabolism abnormalities and inflammation were abolished. FO and PO had no impacts on mRNA and protein expression of receptor-interacting protein-1, interferon regulate factor 3, and nuclear factor-kappa B p65.

CONCLUSION

FO and PO exhibit similar protective effects on metabolic disorders and inflammation through inhibiting TLR4 signaling in a manner dependent on MyD88. These findings highlight plant ω-3 PUFA as an attractive alternative source of marine ω-3 PUFA and reveal a mechanistic insight for preventive benefits of ω-3 PUFA in obesity and related metabolic diseases.

Unwrapping the mechanisms of ceramide and fatty acid-initiated signals leading to immune-inflammatory responses in obesity

Obesity is considered a global epidemic developed in part as a consequence of the overconsumption of high fat diets. One of the main negative outcomes of obesity is the development of low-grade chronic systemic inflammation, induced by dysregulated immune responses, which can lead to multiple obesity-related diseases. Ceramides are a group of bioactive lipids known to be elevated in obesity and obesity-associated conditions, including cardiovascular disease and type II diabetes. Ceramides may be key players in promoting an obesity-induced inflammatory environment due to their ability to activate key pathways such as Toll-like receptor 4 (TLR4) and NLR pyrin domain containing receptor 3 (Nlrp3), while studies have shown that inhibition of ceramide synthesis gives rise to an anti-inflammatory environment. N-3 polyunsaturated fatty acids (n-3 PUFA) have been of interest due to their anti-inflammatory actions and shown to have beneficial effects in obesity-related diseases. This review will highlight the impact of ceramides in promoting an obesity-induced inflammatory microenvironment and discuss how n-3 PUFA could potentially counteract these responses and have a regulatory effect promoting immune homeostasis.

Attenuation of Oxidative Stress and Inflammatory Response by Chronic Cannabidiol Administration Is Associated with Improved n-6/n-3 PUFA Ratio in the White and Red Skeletal Muscle in a Rat Model of High-Fat Diet-Induced Obesity

The consumption of fatty acids has increased drastically, exceeding the nutritional requirements of an individual and leading to numerous metabolic disorders. Recent data indicate a growing interest in using cannabidiol (CBD) as an agent with beneficial effects in the treatment of obesity. Therefore, our aim was to investigate the influence of chronic CBD administration on the n-6/n-3 polyunsaturated fatty acids (PUFAs) ratio in different lipid fractions, inflammatory pathway and oxidative stress parameters in the white and red gastrocnemius muscle. All the designed experiments were performed on Wistar rats fed a high-fat diet (HFD) or a standard rodent diet for seven weeks and subsequently injected with CBD (10 mg/kg once daily for two weeks) or its vehicle. Lipid content and oxidative stress parameters were assessed using gas-liquid chromatography (GLC), colorimetric and/or immunoenzymatic methods, respectively. The total expression of proteins of an inflammatory pathway was measured by Western blotting. Our results revealed that fatty acids (FAs) oversupply is associated with an increasing oxidative stress and inflammatory response, which results in an excessive accumulation of FAs, especially of n-6 PUFAs, in skeletal muscles. We showed that CBD significantly improved the n-6/n-3 PUFA ratio and shifted the equilibrium towards anti-inflammatory n-3 PUFAs, particularly in the red gastrocnemius muscle. Additionally, CBD prevented generation of lipid peroxidation products and attenuated inflammatory response in both types of skeletal muscle. In summary, the results mentioned above indicate that CBD presents potential therapeutic properties with respect to the treatment of obesity and related disturbances.

The effects of flaxseed supplementation on gene expression and inflammation in ulcerative colitis patients: An open-labelled randomised controlled trial

AIMS

Inflammatory bowel disease, a chronic inflammatory disorder of the intestinal mucosa, is a clinical presentation of Crohn's disease and ulcerative colitis (UC). This study investigated the effect of grounded flaxseed (GF) and flaxseed oil (FO) on clinical biomarkers, quality of life and diseases activity in patients with UC. This research was conducted among 90 patients with UC for 12 weeks using an open-labelled randomised controlled trial design.

METHODS

The participants were randomly assigned into two intervention groups supplemented with GF (30 gr/day) and FO (10 gr/day) as well as a control group. The participants' data were collected prior to and 12 weeks after the intervention. The one-way analysis of variance was run to compare variables.

RESULTS

A total of 75 patients completed the study. After the intervention, hs-CRP (P < .001) and Mayo score (P < .001) were reduced significantly, but quality of life was increased significantly (P < .001) in the GF and FO groups compared with the control. A significant increase was observed in IL-10 concentration in the FO group, but no significant change was found in serum levels of IL-10 in the control group. Moreover, the decrease in Mayo score was greater in patients at more severe stages of the disease (P < .05). No difference was observed between the intervention groups and control group in mRNA expression level of TLR4 at the 12th week.

CONCLUSION

In conclusion, grounded flaxseed and FO attenuated systemic inflammation and improved disease severity in UC patients.

Role of 2‑series prostaglandins in the pathogenesis of type 2 diabetes mellitus and non‑alcoholic fatty liver disease (Review)

Nowadays, metabolic syndromes are emerging as global epidemics, whose incidence are increasing annually. However, the efficacy of therapy does not increase proportionately with the increased morbidity. Type 2 diabetes mellitus (T2DM) and non-alcoholic fatty liver disease (NAFLD) are two common metabolic syndromes that are closely associated. The pathogenic mechanisms of T2DM and NAFLD have been studied, and it was revealed that insulin resistance, hyperglycemia, hepatic lipid accumulation and inflammation markedly contribute to the development of these two diseases. The 2-series prostaglandins (PGs), a subgroup of eicosanoids, including PGD₂, PGE₂, PGF_2α and PGI₂, are converted from arachidonic acid catalyzed by the rate-limiting enzymes cyclooxygenases (COXs). Considering their wide distribution in almost every tissue, 2-series PG pathways exert complex and interlinked effects in mediating pancreatic β-cell function and proliferation, insulin sensitivity, fat accumulation and lipolysis, as well as inflammatory processes. Previous studies have revealed that metabolic disturbances, such as hyperglycemia and hyperlipidemia, can be improved by treatment with COX inhibitors. At present, an accumulating number of studies have focused on the roles of 2-series PGs and their metabolites in the pathogenesis of metabolic syndromes, particularly T2DM and NAFLD. In the present review, the role of 2-series PGs in the highly intertwined pathogenic mechanisms of T2DM and NAFLD was discussed, and important therapeutic strategies based on targeting 2-series PG pathways in T2DM and NAFLD treatment were provided.

Dietary low ratio of n-6/n-3 polyunsaturated fatty acids improve type 2 diabetes mellitus via activating brown adipose tissue in male mice

The ratio n-6/n-3 polyunsaturated fatty acids (PUFA) has been caused widespread discussion. However, the best ratio and mechanism of n-6/n-3 PUFA in type 2 diabetes mellitus (T2DM) are largely unknown. This study investigated the effects of different ratio of n-6/n-3 PUFA diets on brown adipose tissue (BAT) and T2DM in mice. Results showed that compared with high ratio of n-6/n-3 PUFA (50:1) diet, lower ratio of n-6/n-3 PUFA (1:1 and 5:1) diets significantly increased BAT mass by 67.55% and 60.49%, decreased the fasting blood glucose (24.87% and 20.64%), total cholesterol (32.9% and 23.84%), triglyceride (33.51% and 29.62%), low-density lipoprotein cholesterol (19.23% and 17.38%), and increased glucose tolerance by 21.99% and 15.52%. Further, qRT-PCR analyses indicated that lower ratio of n-6/n-3 PUFA diets activated BAT, increased the expression of Ucp1, β-3AR, PPAR-γ, cAMP, GLU1, HSL, LPL, and PGC-1α, further improved lipid and glucose metabolism in T2DM mice. In conclusion, this study substantiated that the lower ratio of n-6/n-3 PUFA (1:1 and 5:1) improve symptoms associated with T2DM via activating BAT. PRACTICAL APPLICATION: Dietary ratio of n-6/n-3 polyunsaturated fatty acids is essential for the improvement of chronic diseases. Our current study showed that 1:1 or 5:1 ratio of n-6/n-3 polyunsaturated fatty acids had better efficiency for type 2 diabetes mellitus via activating brown adipose tissue when compared with 1:50. This finding provided useful guidance for the daily diet of patients with diabetes.

Increased Omega-3 Fatty Acid Intake Is Inversely Associated with Subclinical Inflammation in Healthy Elderly Men, Based on the 2015-2018 Korean National Health and Nutrition Examination Survey

(1) Background: Subclinical inflammation as a risk factor of cardiovascular diseases was clinically measured using C-reactive protein (CRP) level. (2) Methods: This study was cross-sectionally designed based the 2015–2018 Korean National Health and Nutrition Examination Survey (KNHANES). The ratio of daily omega-3 fatty acids to energy intake (ω3FA ratio) was classified into four quartile groups (Q1, <0.3%; Q2, 0.3%–<0.6%; Q3, 0.6%–<1.0%; and Q4, ≥1.0% in both sexes). Logistic regression analysis was conducted to investigate the association between the ω3FA ratio and subclinical inflammation defined as CRP levels ≥3 mg/dL. (3) Results: The ω3FA ratio in subjects without and with subclinical inflammation was 0.8% and 0.7% in men (p-value = 0.001), and 0.8% and 0.8% in women (p-value = 0.491), respectively. The prevalence of subclinical inflammation in males decreased with increasing quartile of ω3FA ratio (12.9%, 9.6%, 7.4%, and 7.7%, p-value = 0.033), while female prevalence was not significant among quartile groups. Compared to Q1, odds ratios (95% confidence intervals) for subclinical inflammation of Q2, Q3, and Q4 were 0.740 (0.465–1.177), 0.564 (0.341–0.930), and 0.549 (0.317–0.953) in males, and 1.066 (0.653–1.741), 1.105 (0.600–1.718), and 0.934 (0.556–1.571) in females after full adjustment. (4) Conclusion: The ω3FA ratio is associated with subclinical inflammation in men.

Combined Effects of Plant Sterols with Low Ratio of n-6/n-3 Polyunsaturated Fatty Acids against Atherosclerosis in ApoE-/- Mice

The effects of low ratio of n-6/n-3 polyunsaturated fatty acids (PUFA) have been clarified against atherosclerosis. Increasing evidence indicated that plant sterols (PS) have a significant cholesterol-lowering effect. This study explored the effects of PS combined with n-6/n-3 (2:1) PUFA on atherosclerosis and investigated the possible mechanism. In ApoE^-/- mice, the milk fat in high fat diets was replaced with n-6/n-3 (2:1) PUFA alone or supplemented with 6% PS for 16 weeks. Results demonstrated that PS combined with PUFA exerted commentary and synergistic effects on ameliorating atherosclerosis, improving lipid metabolism and lipid deposition in liver, and alleviating inflammatory response. These changes were accompanied with decreased serum TC, TG, LDL-C and increased fecal cholesterol efflux, as well as the lower inflammatory cytokine CRP, IL-6, TNF-α. It is suggested that the underlying mechanism of PS combined with n-6/n-3 (2:1) PUFA promoting the fecal cholesterol efflux may be mediated by liver X receptor α/ATP-binding cassette transporter A1 pathway.

Associations among Dietary Omega-3 Polyunsaturated Fatty Acids, the Gut Microbiota, and Intestinal Immunity

Omega-3 polyunsaturated fatty acids (omega-3 PUFAs), which are essential fatty acids that humans should obtain from diet, have potential benefits for human health. In addition to altering the structure and function of cell membranes, omega-3 PUFAs (docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), alpha-linolenic acid (ALA), and docosapentaenoic acid (DPA)) exert different effects on intestinal immune tolerance and gut microbiota maintenance. Firstly, we review the effect of omega-3 PUFAs on gut microbiota. And the effects of omega-3 PUFAs on intestinal immunity and inflammation were described. Furthermore, the important roles of omega-3 PUFAs in maintaining the balance between gut immunity and the gut microbiota were discussed. Additional factors, such as obesity and diseases (NAFLD, gastrointestinal malignancies or cancer, bacterial and viral infections), which are associated with variability in omega-3 PUFA metabolism, can influence omega-3 PUFAs–microbiome–immune system interactions in the intestinal tract and also play roles in regulating gut immunity. This review identifies several pathways by which the microbiota modulates the gut immune system through omega-3 PUFAs. Omega-3 supplementation can be targeted to specific pathways to prevent and alleviate intestinal diseases, which may help researchers identify innovative diagnostic methods.

Dietary ω-3 fatty acids and their influence on inflammation via Toll-like receptor pathways

Dietary intake of long-chain, highly unsaturated ω-3 fatty acids (FAs) is considered indispensable for humans. The ω-3 FAs have been known to be anti-inflammatory and immunomodulatory dietary factors; however, the modes of action on pathogen recognition receptors (PRRs) and downstream signaling pathways have not been fully elucidated. Dietary sources contain various amounts of ω-3 long-chain fatty acids (LCFAs) of different lengths and the association between intake of these polyunsaturated fatty acids (PUFAs) with underlying mechanisms of various immune-related disorders can be of great interest. The potential anti-inflammatory role for ω-3 LCFAs can be explained by modification of lipid rafts, modulation of inflammatory mediators such as cytokines and PRRs. Toll-like receptors (TLRs) are a group of PRRs that play an important role in the recognition of bacterial infections and ω-3 FAs have been implicated in the modulation of downstream signaling of TLR-4, an important receptor for recognition of gram-negative bacteria. The ω-3 FAs docosahexaenoic acid and eicosapentaenoic acid have been investigated in vivo and in vitro for their effects on the nuclear factor-κB activation pathway. Identification of the effects of ω-3 FAs on other key molecular factors like prostaglandins and leukotrienes and their signals may help the recognition and development of medicines to suppress the main mediators and turn on the expression of anti-inflammatory cytokines and nuclear receptors.

Diets enriched with coconut, fish, or olive oil modify peripheral metabolic effects of ozone in rats

Dietary factors may modulate metabolic effects of air pollutant exposures. We hypothesized that diets enriched with coconut oil (CO), fish oil (FO), or olive oil (OO) would alter ozone-induced metabolic responses. Male Wistar-Kyoto rats (1-month-old) were fed normal diet (ND), or CO-, FO-, or OO-enriched diets. After eight weeks, animals were exposed to air or 0.8 ppm ozone, 4 h/day for 2 days. Relative to ND, CO- and OO-enriched diet increased body fat, serum triglycerides, cholesterols, and leptin, while all supplements increased liver lipid staining (OO > FO > CO). FO increased n-3, OO increased n-6/n-9, and all supplements increased saturated fatty-acids. Ozone increased total cholesterol, low-density lipoprotein, branched-chain amino acids (BCAA), induced hyperglycemia, glucose intolerance, and changed gene expression involved in energy metabolism in adipose and muscle tissue in rats fed ND. Ozone-induced glucose intolerance was exacerbated by OO-enriched diet. Ozone increased leptin in CO- and FO-enriched groups; however, BCAA increases were blunted by FO and OO. Ozone-induced inhibition of liver cholesterol biosynthesis genes in ND-fed rats was not evident in enriched dietary groups; however, genes involved in energy metabolism and glucose transport were increased in rats fed FO and OO-enriched diet. FO- and OO-enriched diets blunted ozone-induced inhibition of genes involved in adipose tissue glucose uptake and cholesterol synthesis, but exacerbated genes involved in adipose lipolysis. Ozone-induced decreases in muscle energy metabolism genes were similar in all dietary groups. In conclusion, CO-, FO-, and OO-enriched diets modified ozone-induced metabolic changes in a diet-specific manner, which could contribute to altered peripheral energy homeostasis.

Polyunsaturated Fatty Acid Diet and Upregulation of Lipoxin A4 Reduce the Inflammatory Response of Preeclampsia

The aim of this study was to investigate the effects and mechanisms of polyunsaturated fatty acids (PUFAs) and lipoxin A4 (LXA4) on preeclampsia (PE). The LXA4 level was significantly reduced in PE rats. The PUFA diet upregulated the expressions of lipoxygenase 12 (LOX12) and lipoxygenase 15 (LOX15) and downregulated those of cyclooxygenase-2, tumor necrosis factor-α (TNF-α), and endoglin. Lipopolysaccharides could inhibit cell growth and cause inflammatory response, while the presence of PUFAs inhibited the inflammatory response and promoted the expressions of LOX12, LOX15, and LXA4. Nordihydroguaiaretic acid (NDGA) regulated LXA4 expression and inflammation levels by affecting LOX. Inhibition of lipoxygenase 5 activity by NDGA upregulated the expressions of LOX12 and LOX15, while LXA4 reversed LXA4, nitric oxide downregulation, and TNF-α upregulation by NDGA. A decrease in LXA4 levels played an important role in the development and progression of PE.

Dietary Options for Rodents in the Study of Obesity

Obesity and its associated metabolic diseases are currently a priority research area. The increase in global prevalence at different ages is having an enormous economic and health impact. Genetic and environmental factors play a crucial role in the development of obesity, and diet is one of the main factors that contributes directly to the obesogenic phenotype. Scientific evidence has shown that increased fat intake is associated with the increase in body weight that triggers obesity. Rodent animal models have been extremely useful in the study of obesity since weight gain can easily be induced with a high-fat diet. Here, we review the dietary patterns and physiological mechanisms involved in the dynamics of energy balance. We report the main dietary options for the study of obesity and the variables to consider in the use of a high-fat diet, and assess the progression of obesity and diet-induced thermogenesis.

Dietary Fat Quality and Pre-diabetes: A Case-control Study

Background:

The relationship between dietary fat quality (DFQ) indices and pre-diabetes has not been well studied. This study aimed to determine the association of DFQ indices and fatty acid intake with pre-diabetes.

Methods:

This case-control study included 150 subjects with normal fasting blood glucose (FBG) and 147 pre-diabetic subjects. Dietary intake was assessed by a validated food-frequency questionnaire. DFQ indices including atherogenicity (AI) and thrombogenicity (TI), the ratios of hypo- and hypercholesterolemic (h:H), polyunsaturated:saturated (P:S) and n-3:n-6 polyunsaturated fatty acids were calculated. FBG test and 2-hour oral glucose tolerance test (OGTT) were measured.

Results:

After adjustment for some confounding variables, a positive association was found between intake of total saturated fatty acids (SFA), myristic acid, palmitic acid, and pre-diabetes, and a negative association was observed among n-3 polyunsaturated fatty acids, eicosapentaenoic, docosahexaenoic and arachidonic acids intake and pre-diabetes. AI was found to be positively associated with pre-diabetes (OR 6.68, 95% CI 2.57-17.34). An inverse relationship was observed between n-3:n-6 (OR 0.37, 95% CI 0.14-0.93) and h:H (OR 0.20, 95% CI 0.07-0.52) ratios with pre-diabetes.

Conclusions:

Higher intake of dietary n-3 fatty acids was adversely, whereas SFA intake was positively related to pre-diabetes morbidity. DFQ indices may be a useful measure to investigate fat intakes and blood glucose disturbances.