Explore the vast range of titles available.

Gut microbiota mediates the effects of diet, thereby modifying host metabolism and the incidence of metabolic disorders. Increased consumption of omega-6 polyunsaturated fatty acid (PUFA) that is abundant in Western diet contributes to obesity and related diseases. Although gut-microbiota-related metabolic pathways of dietary PUFAs were recently elucidated, the effects on host physiological function remain unclear. Here, we demonstrate that gut microbiota confers host resistance to high-fat diet (HFD)-induced obesity by modulating dietary PUFAs metabolism. Supplementation of 10-hydroxy- cis -12-octadecenoic acid (HYA), an initial linoleic acid-related gut-microbial metabolite, attenuates HFD-induced obesity in mice without eliciting arachidonic acid-mediated adipose inflammation and by improving metabolic condition via free fatty acid receptors. Moreover, Lactobacillus -colonized mice show similar effects with elevated HYA levels. Our findings illustrate the interplay between gut microbiota and host energy metabolism via the metabolites of dietary omega-6-FAs thereby shedding light on the prevention and treatment of metabolic disorders by targeting gut microbial metabolites. The gut microbiome is an important regulator of metabolic health. Here the authors show that intestinal bacteria metabolize dietary linoleic acid to 10-hydroxy- cis -12-octadecenoic acid (HYA) which confers host resistance to high fat diet-induced obesity in mice.

Omega-3 (ω-3) and omega-6 (ω-6) polyunsaturated fatty acids (PUFAs) are nowadays desirable components of oils with special dietary and functional properties. Their therapeutic and health-promoting effects have already been established in various chronic inflammatory and autoimmune diseases through various mechanisms, including modifications in cell membrane lipid composition, gene expression, cellular metabolism, and signal transduction. The application of ω-3 and ω-6 PUFAs in most common skin diseases has been examined in numerous studies, but their results and conclusions were mostly opposing and inconclusive. It seems that combined ω-6, gamma-linolenic acid (GLA), and ω-3 long-chain PUFAs supplementation exhibits the highest potential in diminishing inflammatory processes, which could be beneficial for the management of inflammatory skin diseases, such as atopic dermatitis, psoriasis, and acne. Due to significant population and individually-based genetic variations that impact PUFAs metabolism and associated metabolites, gene expression, and subsequent inflammatory responses, at this point, we could not recommend strict dietary and supplementation strategies for disease prevention and treatment that will be appropriate for all. Well-balanced nutrition and additional anti-inflammatory PUFA-based supplementation should be encouraged in a targeted manner for individuals in need to provide better management of skin diseases but, most importantly, to maintain and improve overall skin health.

Unsaturated fatty acids, particularly omega-3 and omega-6 polyunsaturated fatty acids, have garnered increasing scientific interest due to their therapeutic potential in chronic disease management. Dietary sources such as milk provide essential unsaturated fatty acids, including linoleic acid and α-linolenic acid. Current evidence indicates that these compounds and their derivatives regulate critical physiological processes, such as neurodevelopment, visual function, immune modulation, and cardiovascular homeostasis. Their multifunctional roles encompass the structural maintenance of biological membranes, cardioprotective effects, anti-inflammatory and anti-tumor activities, and metabolic regulation. However, despite established associations between unsaturated fatty acids and chronic diseases, the mechanistic contributions of omega-3 and omega-6 polyunsaturated fatty acids to complex neuropsychiatric disorders remain poorly characterized. Furthermore, the controversial role of omega-6 polyunsaturated fatty acids in chronic disease pathogenesis necessitates urgent clarification. This review systematically examines the structural properties, molecular mechanisms, and therapeutic applications of omega-3 and omega-6 polyunsaturated fatty acids in cardiovascular diseases, diabetes, cancer, dermatological conditions, neurodegenerative disorders, and depression. By integrating recent advances in dietary science, this work aims to address knowledge gaps in their neuropsychiatric implications and refine evidence-based strategies for chronic disease intervention through optimized nutritional approaches.

Randomised controlled trials (RCT) of mixed n-6 and n-3 PUFA diets, and meta-analyses of their CHD outcomes, have been considered decisive evidence in specifically advising consumption of ‘at least 5–10 % of energy as n-6 PUFA’. Here we (1) performed an extensive literature search and extracted detailed dietary and outcome data enabling a critical examination of all RCT that increased PUFA and reported relevant CHD outcomes; (2) determined if dietary interventions increased n-6 PUFA with specificity, or increased both n-3 and n-6 PUFA (i.e. mixed n-3/n-6 PUFA diets); (3) compared mixed n-3/n-6 PUFA to n-6 specific PUFA diets on relevant CHD outcomes in meta-analyses; (4) evaluated the potential confounding role of trans-fatty acids (TFA). n-3 PUFA intakes were increased substantially in four of eight datasets, and the n-6 PUFA linoleic acid was raised with specificity in four datasets. n-3 and n-6 PUFA replaced a combination of TFA and SFA in all eight datasets. For non-fatal myocardial infarction (MI)+CHD death, the pooled risk reduction for mixed n-3/n-6 PUFA diets was 22 % (risk ratio (RR) 0·78; 95 % CI 0·65, 0·93) compared to an increased risk of 13 % for n-6 specific PUFA diets (RR 1·13; 95 % CI 0·84, 1·53). Risk of non-fatal MI+CHD death was significantly higher in n-6 specific PUFA diets compared to mixed n-3/n-6 PUFA diets (P = 0·02). RCT that substituted n-6 PUFA for TFA and SFA without simultaneously increasing n-3 PUFA produced an increase in risk of death that approached statistical significance (RR 1·16; 95 % CI 0·95, 1·42). Advice to specifically increase n-6 PUFA intake, based on mixed n-3/n-6 RCT data, is unlikely to provide the intended benefits, and may actually increase the risks of CHD and death.

Eating habits have changed dramatically over the years, leading to an imbalance in the ratio of n-6/n-3 polyunsaturated fatty acids (PUFAs) in favour of n-6 PUFAs, particularly in the Western diet. Meanwhile, the incidence of inflammatory bowel disease (IBD) is increasing worldwide. Recent epidemiological data indicate the potential beneficial effect of n-3 PUFAs in ulcerative colitis (UC) prevention, whereas consumption of a higher ratio of n-6 PUFAs versus n-3 PUFAs has been associated with an increased UC incidence. The long-chain dietary n-3 PUFAs are the major components of n-3 fish oil and have been shown to have anti-inflammatory properties in several chronic inflammatory disorders, being involved in the regulation of immunological and inflammatory responses. Despite experimental evidence implying biological plausibility, clinical data are still controversial, especially in Crohn’s disease. Clinical trials of fish-oil derivatives in IBD have produced mixed results, showing beneficial effects, but failing to demonstrate a clear protective effect in preventing clinical relapse. Such data are insufficient to make a recommendation for the use of n-3 PUFAs in clinical practice. Here, we present the findings of a comprehensive literature search on the role of n-3 PUFAs in IBD development and treatment, and highlight new therapeutic perspectives.

The objective of the present study was to investigate the optimal dietary n-6:n-3 PUFA ratios that regulate lipid metabolism and inflammation in pigs. A total of ninety-six cross-bred (Large White × Landrace) growing-finishing pigs (73·8 (sem 1·6) kg) were chosen and fed one of the four isoenergetic diets with n-6:n-3 PUFA ratios of 1:1, 2·5:1, 5:1 and 10:1. The growth performance of pigs fed the diet with an n-6:n-3 PUFA ratio of 5:1 was the best, but the group fed the diet with an n-6:n-3 PUFA ratio of 1:1 had the highest muscle mass and the lowest adipose tissue mass (P< 0·05). The concentrations of IL-6 and IL-1β of pigs fed the diet with an n-6:n-3 PUFA ratio of 1:1 were decreased compared with those of the other groups (P< 0·05). The concentration of adiponectin of pigs fed the diet with an n-6:n-3 PUFA ratio of 1:1 was also markedly decreased, but the concentration of leptin was increased compared with that of the groups fed the diets with n-6:n-3 PUFA ratios of 5:1 and 10:1 (P< 0·05). Additionally, the optimal dietary ratios of n-6:n-3 PUFA of 1:1 and 5:1 markedly suppressed the expression levels of lipid metabolism-related genes and proteins such as phosphoinositide-3-kinase-α, fatty acid transport protein-1 and PPARγ. They also significantly suppressed the expression levels of the inflammatory cytokines IL-1β, TNF-α and IL-6. The results indicated that the optimal n-6:n-3 PUFA ratios of 1:1 and 5:1 exerted beneficial effects on lipid metabolism and inflammatory system, leading to the availability of more energy and nutrients for high performance and homeostatic pathways.

Noncommunicable diseases (NCD) and age-associated diseases (AAD) are some of the gravest health concerns worldwide, accounting for up to 70% of total deaths globally. NCD and AAD, such as diabetes, obesity, cardiovascular disease, and cancer, are associated with low-grade chronic inflammation and poor dietary habits. Modulation of the inflammatory status through dietary components is a very appellative approach to fight these diseases and is supported by increasing evidence of natural and dietary components with strong anti-inflammatory activities. The consumption of bioactive lipids has a positive impact on preventing chronic inflammation and consequently NCD and AAD. Thus, new sources of bioactive lipids have been sought out. Microalgae are rich sources of bioactive lipids such as omega-6 and -3 polyunsaturated fatty acids (PUFA) and polar lipids with associated anti-inflammatory activity. PUFAs are enzymatically and non-enzymatically catalyzed to oxylipins and have a significant role in anti and pro-resolving inflammatory responses. Therefore, a large and rapidly growing body of research has been conducted in vivo and in vitro, investigating the potential anti-inflammatory activities of microalgae lipids. This review sought to summarize and critically analyze recent evidence of the anti-inflammatory potential of microalgae lipids and their possible use to prevent or mitigate chronic inflammation.

Higher indoor particulate matter (PM) concentrations are linked with increased asthma morbidity. Dietary intake of fatty acids, also linked with asthma outcomes, may influence this relationship. To determine the relationship between omega-3 and omega-6 fatty acid intake and pediatric asthma morbidity, and the association between fatty acid intake and strength of indoor, PM-related asthma symptoms, albuterol use, and systemic inflammation. Analyses included 135 children with asthma enrolled in the AsthmaDIET Study. At baseline, 3 months, and 6 months, data included: week-long average home indoor concentration of PM ≤2.5 μm in aerodynamic diameter and PM ≤10 μm in aerodynamic diameter, dietary intake of omega-3 and omega-6 fatty acids, daily symptoms, and peripheral blood leukocytes. Asthma severity and lung function were assessed at baseline. Multivariable regression models, adjusted for known confounders, were used to determine associations between each fatty acid and outcomes of interest, with interaction terms (fatty acids × PM) in longitudinal analyses. Higher omega-6 intake associated with increased odds of increased asthma severity (  = 0.02), and lower FEV /FVC ratio (  = 0.01). Higher omega-3 intake associated with reduced effect of indoor PM ≤2.5 μm in aerodynamic diameter on symptoms (  < 0.01), whereas higher omega-6 intake associated with amplified effect of indoor PM ≤2.5 μm in aerodynamic diameter on symptoms and circulating neutrophil percentage (  < 0.01). Omega-3 and omega-6 intake are associated with pediatric asthma morbidity and may modify the asthmatic response to indoor PM.

n-6 PUFA are well known for their critical role in many physiological functions and seem to reduce risks of CHD. However, some argue that excessive consumption of n-6 PUFA may lead to adverse effects on health and therefore recommend reducing dietary n-6 PUFA intake or fixing an upper limit. In this context, the present work aimed to review evidence on the link between n-6 PUFA and risks of CVD. Epidemiological studies show that n-6 PUFA dietary intake significantly lowers blood LDL-cholesterol levels. In addition, n-6 PUFA intake does not increase several CVD risk factors such as blood pressure, inflammatory markers, haemostatic parameters and obesity. Data from prospective cohort and interventional studies converge towards a specific protective role of dietary n-6 PUFA intake, in particular linoleic acid, against CVD. n-6 PUFA benefits are even increased when SFA intake is also reduced. In regards to studies examined in this narrative review, recommendation for n-6 PUFA intake above 5 %, and ideally about 10 %, of total energy appears justified.

The healthy Nordic diet has been previously shown to have health beneficial effects among subjects at risk of CVD. However, the extent of food changes needed to achieve these effects is less explored. The aim of the present study was to investigate the effects of exchanging a few commercially available, regularly consumed key food items (e.g. spread on bread, fat for cooking, cheese, bread and cereals) with improved fat quality on total cholesterol, LDL-cholesterol and inflammatory markers in a double-blind randomised, controlled trial. In total, 115 moderately hypercholesterolaemic, non-statin-treated adults (25–70 years) were randomly assigned to an experimental diet group (Ex-diet group) or control diet group (C-diet group) for 8 weeks with commercially available food items with different fatty acid composition (replacing SFA with mostly n-6 PUFA). In the Ex-diet group, serum total cholesterol (P<0·001) and LDL-cholesterol (P<0·001) were reduced after 8 weeks, compared with the C-diet group. The difference in change between the two groups at the end of the study was −9 and −11 % in total cholesterol and LDL-cholesterol, respectively. No difference in change in plasma levels of inflammatory markers (high-sensitive C-reactive protein, IL-6, soluble TNF receptor 1 and interferon-γ) was observed between the groups. In conclusion, exchanging a few regularly consumed food items with improved fat quality reduces total cholesterol, with no negative effect on levels of inflammatory markers. This shows that an exchange of a few commercially available food items was easy and manageable and led to clinically relevant cholesterol reduction, potentially affecting future CVD risk.