Relationship between Serum Omega-3 Fatty Acid and Asthma Endpoints

Per and poly-fluoroalkyl substances and respiratory health in an Inuit community

BACKGROUND

Concentrations of plasma per and poly-fluoroalkyl substances (PFAS) are elevated in the Inuit population of Nunavik and may be causing adverse health effects. Respiratory health outcomes have been associated with PFAS, but have not been explored in Inuit communities. The aim of the study was to examine the association between PFAS and respiratory health outcomes, and the moderating role of nutritional biomarkers.

METHODS

We included up to 1298 participants of the Qanuilirpitaa? 2017 survey aged 16-80 years. Generalized regression models were used to estimate the associations between six individual PFAS congeners and four self-reported symptoms, four spirometry measures, and physician-diagnosed asthma. Outcomes associated with PFAS from single chemical models were further explored using Bayesian Kernel Machine Regression (BKMR). The modifying effect of n-3 PUFA in red blood cell quartiles and vitamin D deficiency were examined on the associations between PFAS and respiratory outcomes.

RESULTS

PFNA and PFOS were associated with asthma (odds ratio (OR) 1.61, 95% confidence interval (CI) 1.12, 2.32; OR 1.45 95% CI 1.04, 2.03). PFOA, PFNA, PFDA and PFHxS were associated with a decrease in the ratio between the forced expiratory volume in the first second and forced vital capacity (FEV1/FVC). No associations were observed with self-reported respiratory symptoms. No associations were observed between a PFAS mixture and asthma. Some associations were modified by nutritional factors, namely, stronger associations between PFOA and PFHxS and asthma with lower n-3 PUFA levels and stronger associations between PFDA, PFUnDA and PFOS and FEV1/FVC with vitamin D deficiency.

CONCLUSION

These findings add to the growing literature on the impacts of PFAS on respiratory health, and the importance of their global regulation. Associations were modified by nutritional factors pointing to the nutritional value of traditional Inuit foods.

Dietary patterns and risk of developing asthma among pre-schoolers

BACKGROUND

Early childhood dietary patterns have been identified as potential factors that can influence the development of asthma in children. The objective of the study was to determine the association between dietary patterns, identified through principal component analysis (PCA), and asthma in pre-schoolers.

METHODS

This unmatched case-control study used data from 3145 pre-schoolers participating in the parent population-based observational study conducted in a District Municipality, Province. The study consisted of 189 pre-schoolers (63 with asthma, 126 controls) between 1 and 8 years. We identified primary dietary patterns by conducting a PCA on reported food consumption data from the Quantitative Food Frequency Questionnaire (QFFQ). Multivariate logistic regression models determined the relationship between food patterns and asthma.

RESULTS

The results of our study identified four primary dietary patterns that defined the dietary preferences of the pre-schoolers: Meat general and dressings pattern, Healthy dietary pattern, Sugary and/or sweetened drinks pattern, and Mixed dietary pattern. The consumption of sugary and sweetened drinks (adjusted OR 7.0, 95% CI: 2.3-21.1-1; p = 0.00) as well as a Mixed dietary pattern (adjusted OR 4.0, 95% CI: 1.4-11.1; p = 0.03) were positively associated with a higher probability of developing asthma. A Healthy dietary pattern (adjusted OR 0.02, 95% CI: 0.00-0.09; p = 0.00) was negatively associated with an increased likelihood of presenting with asthma.

CONCLUSIONS

In the current study, a Healthy dietary pattern was negatively associated with an increased likelihood of presenting with asthma. Diet modification may be a potential intervention to impact the increasing prevalence of this disease.

Genetically Determined Circulating Saturated and Unsaturated Fatty Acids and the Occurrence and Exacerbation of Chronic Obstructive Pulmonary Disease-A Two-Sample Mendelian Randomization Study

Research on dietary fatty acids (FAs) and lung health has reported skeptical findings. This study aims to examine the causal relationship between circulating FAs and Chronic Obstructive Pulmonary Disease (COPD) onset and exacerbation, using a two-sample Mendelian Randomization (MR) analysis. Strong and independent genetic variants of FAs were obtained from the UK Biobank of European ancestry. The exposure traits included saturated FA (SFA), poly- and mono-unsaturated FA (PUFA and MUFA), omega-3 and omega-6 PUFA, docosahexaenoic acid (DHA), and linoleic acid (LA), all expressed as total FA (TFA) percentages. Summary statistics for COPD outcomes were obtained from the FinnGen consortium including COPD, COPD hospitalization, COPD/asthma-related infections, COPD-related respiratory insufficiency, and COPD/asthma/interstitial lung disease (ILD)-related pneumonia. The inverse-variance weighted (IVW) was the primary MR approach. MR-Egger regression and MR-PRESSO were utilized to evaluate heterogeneity and pleiotropy. MR-PRESSO tests suggested no obvious horizontal pleiotropy. MR results by the IVW approach indicated that the genetically high SFA/TFA levels were associated with an increased risk of COPD/asthma/ILD-related pneumonia (OR: 1.275, 95%CI: 1.103-1.474, p for FDR = 0.002). No significant relationship was observed between other types of FAs and COPD outcomes. Our MR analysis suggests that there is weak evidence that the genetically predicted high SFA/TFA was associated with an increased risk of pneumonia.

Severe Allergy as a Chronic Inflammatory Condition From a Systems Biology Perspective

Persistent and unresolved inflammation is a common underlying factor observed in several and seemingly unrelated human diseases, including cardiovascular and neurodegenerative diseases. Particularly, in atopic conditions, acute inflammatory responses such as those triggered by insect venom, food or drug allergies possess also a life-threatening potential. However, respiratory allergies predominantly exhibit late immune responses associated with chronic inflammation, that can eventually progress into a severe phenotype displaying similar features as those observed in other chronic inflammatory diseases, as is the case of uncontrolled severe asthma. This review aims to explore the different facets and systems involved in chronic allergic inflammation, including processes such as tissue remodelling and immune cell dysregulation, as well as genetic, metabolic and microbiota alterations, which are common to other inflammatory conditions. Our goal here was to deepen on the understanding of an entangled disease as is chronic allergic inflammation and expose potential avenues for the development of better diagnostic and intervention strategies.

Evaluation of elevated plasma fatty acids as relevant factors for adult-onset asthma: The Nagahama Study

BACKGROUND

Obesity and increased body mass index (BMI) are the known risk factors for adult-onset asthma. Serum free fatty acid (FFA) and other blood lipid levels are generally elevated in patients with obesity and may be involved in the onset of asthma. However, it remains largely unknown. This study aimed to elucidate the relationship between plasma fatty acids and new-onset asthma.

METHODS

This community-based Nagahama Study in Japan enrolled 9804 residents. We conducted self-reporting questionnaires, lung function tests, and blood tests at baseline and 5 years later as follow-up. At the follow-up, plasma fatty acids were measured using gas chromatography-mass spectrometry. Body composition analysis was also measured at the follow-up. The associations between fatty acids and new-onset asthma were evaluated using a multifaceted approach, including targeted partial least squares discriminant analysis (PLS-DA).

RESULTS

In PLS-DA for new-onset asthma, palmitoleic acid was identified as the fatty acid most associated with asthma onset. In the multivariable analysis, higher levels of FFA, palmitoleic acid, or oleic acid were significantly associated with new-onset asthma, independent of other confounding factors. The high body fat percentage itself was not the relevant factor, but showed a positive interaction with plasma palmitoleic acid for new-onset asthma. When stratified by gender, the impacts of higher levels of FFA or palmitoleic acid on new-onset asthma remained significant in females, but not in males.

CONCLUSIONS

Elevated levels of plasma fatty acids, particularly palmitoleic acid, may be a relevant factor for new-onset asthma.

GPR120/FFAR4 stimulation attenuates airway remodeling and suppresses IL-4- and IL-13-induced airway epithelial injury via inhibition of STAT6 and Akt

BACKGROUND

Airway remodeling is associated with severity and treatment insensitivity in asthma. This study aimed to investigate the effects of G protein-coupled receptor 120 (GPR120) stimulation on alleviating allergic inflammation and remodeling of airway epithelium.

RESEARCH DESIGN AND METHODS

Ovalbumin (OVA)-challenged BALB/c mice and type-2-cytokine (IL-4 and IL-13)-exposed 16HBE human bronchial epithelial cells were treated with GSK137647A, a selective GPR120 agonist. Markers of allergic inflammation and airway remodeling were determined.

RESULTS

GSK137647A attenuated inflammation and mucus secretion in airway epithelium of OVA-challenged mice. Stimulation of GPR120 in 16HBE suppressed expression of asthma-associated cytokines and cytokine-induced expression of pathogenic mucin-MUC5AC. These effects were abolished by co-treatment with AH7614, a GPR120 antagonist. Moreover, GPR120 stimulation in 16HBE cells reduced expression of fibrotic markers including fibronectin protein and ACTA2 mRNA and inhibited epithelial barrier leakage induced by type-2 inflammation via rescuing expression of zonula occludens-1 protein. Furthermore, GPR120 stimulation prevented the cytokine-induced airway epithelial remodeling via suppression of STAT6 and Akt phosphorylation.

CONCLUSIONS

Our findings suggest that GPR120 activation alleviates allergic inflammation and remodeling of airway epithelium partly through inhibition of STAT6 and Akt. GPR120 may represent a novel therapeutic target for diseases associated with remodeling of airway epithelium, including asthma.

Healthy eating index (HEI) as the predictor of asthma: Findings from NHANES

BACKGROUND&AIMS

Previous studies have shown that the formation and development of asthma are closely related to diet. A proper diet can control asthma onset although the precise dietary components involved in preventing or delaying the onset of asthma remain unclear. The healthy eating index (HEI-2015) is a dietary score that measures the overall diet quality as well as the quality of several dietary components. We aimed to explore the relationship between HEI and asthma.

METHODS

This is a cross-sectional study that used data from the 2005 to 2018 National Health and Nutritional Examination Survey (NHANES) in adults (n = 26,567). Our inclusion criteria were adults ≥18 years, completion of asthma-related questionnaires and availability of HEI data. Weighted logistic regression was performed to assess the association between asthma and HEI after adjusting for several covariates.

RESULTS

Patients with asthma were more likely to be female, come from a poorer background, have a raised body mass index (BMI) and a lower HEI total score. Higher HEI total scores were associated with a lower risk of asthma in adults. In addition, eating more whole fruits, more greens and beans, more total protein foods, more seafood and plant proteins, and having a reduced dietary intake of added sugars reduces the risk of asthma. In asthmatic populations, higher HEI scores are associated with older age at onset of asthma.

CONCLUSION

There is an inverse association between the HEI and asthma. This underlines the importance of improving adherence to healthy dietary patterns in the prevention of asthma.

IgE-Mediated Shellfish Allergy in Children

Shellfish, including various species of mollusks (e.g., mussels, clams, and oysters) and crustaceans (e.g., shrimp, prawn, lobster, and crab), have been a keystone of healthy dietary recommendations due to their valuable protein content. In parallel with their consumption, allergic reactions related to shellfish may be increasing. Adverse reactions to shellfish are classified into different groups: (1) Immunological reactions, including IgE and non-IgE allergic reactions; (2) non-immunological reactions, including toxic reactions and food intolerance. The IgE-mediated reactions occur within about two hours after ingestion of the shellfish and range from urticaria, angioedema, nausea, and vomiting to respiratory signs and symptoms such as bronchospasm, laryngeal oedema, and anaphylaxis. The most common allergenic proteins involved in IgE-mediated allergic reactions to shellfish include tropomyosin, arginine kinase, myosin light chain, sarcoplasmic calcium-binding protein, troponin c, and triosephosphate isomerase. Over the past decades, the knowledge gained on the identification of the molecular features of different shellfish allergens improved the diagnosis and the potential design of allergen immunotherapy for shellfish allergy. Unfortunately, immunotherapeutic studies and some diagnostic tools are still restricted in a research context and need to be validated before being implemented into clinical practice. However, they seem promising for improving management strategies for shellfish allergy. In this review, epidemiology, pathogenesis, clinical features, diagnosis, and management of shellfish allergies in children are presented. The cross-reactivity among different forms of shellfish and immunotherapeutic approaches, including unmodified allergens, hypoallergens, peptide-based, and DNA-based vaccines, are also addressed.

Association between circulating fatty acid metabolites and asthma risk: a two-sample bidirectional Mendelian randomization study

BACKGROUND

Fatty acids are involved in a wide range of immunological responses in humans. Supplementation of polyunsaturated fatty acids has been reported to help alleviate symptoms and airway inflammation in asthma patients, whereas the effects of fatty acids on the actual risk of asthma remain controversial. This study comprehensively investigated the causal effects of serum fatty acids on asthma risk using two-sample bidirectional Mendelian Randomization (MR) analysis.

METHODS

Genetic variants strongly associated with 123 circulating fatty acid metabolites were extracted as instrumental variables, and a large GWAS data of asthma was used to test effects of the metabolites on this outcome. The inverse-variance weighted method was used for primary MR analysis. The weighted median, MR-Egger regression, MR-PRESSO, and leave-one-out analyses were utilized to evaluate heterogeneity and pleiotropy. Potential confounders were adjusted by performing multivariable MR analyses. Reverse MR analysis was also conducted to estimate the causal effect of asthma on candidate fatty acid metabolites. Further, we performed colocalization analysis to examine the pleiotropy of variants within the fatty acid desaturase 1 (FADS1) locus between the significant metabolite traits and the risk of asthma. Cis-eQTL-MR and colocalization analysis were also performed to determine the association between RNA expression of FADS1 and asthma.

RESULTS

Genetically instrumented higher average number of methylene groups was causally associated with a lower risk of asthma in primary MR analysis, while inversely, the higher ratio of bis-allylic groups to double bonds and the higher ratio of bis-allylic groups to total fatty acids, were associated with higher probabilities of asthma. Consistent results were obtained in multivariable MR when adjusted for potential confounders. However, these effects were completely eliminated after SNPs correlated with the FADS1 gene were excluded. The reverse MR also found no causal association. The colocalization analysis suggested that the three candidate metabolite traits and asthma likely share causal variants within the FADS1 locus. In addition, the cis-eQTL-MR and colocalization analyses demonstrated a causal association and shared causal variants between FADS1 expression and asthma.

CONCLUSIONS

Our study supports a negative association between several PUFA traits and the risk of asthma. However, this association is largely attributed to the influence of FADS1 polymorphisms. The results of this MR study should be carefully interpreted given the pleiotropy of SNPs associated with FADS1.

Pharmacological evaluation of the effects of enzymatically liberated fish oil on eosinophilic inflammation in animal models

The inappropriate activation of eosinophils is a well-recognized driver of various human inflammatory diseases including asthma, chronic rhinitis, and various gastrointestinal diseases, including eosinophilic esophagitis. Steroids, both topical and systemic, remain a cornerstone of treatment and can be highly effective. However, some individuals suffer side effects, unresolved symptoms, or both. OmeGo, an enzymatically liberated fish oil, has demonstrated anti-inflammatory and antioxidant properties as well the reduction of the activation, migration, and survival of eosinophils. Two animal models of eosinophilic inflammation were used to further assess OmeGo's profile. A house dust mite model of induced asthma showed a significant reduction in eosinophilic lung inflammation compared to the negative control, linoleic acid. The CRTH2 antagonist fevipiprant showed a similar eosinophilic inhibitory profile to OmeGo. In contrast, cod liver oil had no impact on any measure of inflammation. A guinea pig model of mild intraperitoneal eosinophilia showed a significant reduction in eosinophil activity by OmeGo, assessed by chemotaxis and chemokinesis. Apolipoprotein A-IV, an endogenous human protein with anti-inflammatory actions, showed a similar but numerically lower effect. OmeGo therefore combines a consistent antieosinophilic action with the known anti-inflammatory effects of polyunsaturated fatty acids. Proof-of-concept studies in asthma are warranted.

Evaluating the Effect of Eicosapentaenoic Acid in Children With Atopic Dermatitis: A Randomized Triple-Blind Clinical Trial

OBJECTIVE

To evaluate the effects of dietary eicosapentaenoic acid (EPA) in children with atopic dermatitis.

METHODS

Forty-eight children with atopic dermatitis were randomly allocated to receive either 250 mg twice daily EPA (n = 24) or placebo (n = 24) for 4 weeks. The absolute improvement in the SCORing Atopic Dermatitis (SCORAD) index and the necessity to use topical corticosteroids was evaluated.

RESULTS

Based on an intention-to-treat analysis, after 2 weeks the scores decreased to 30.50 ± 8.91 and 38.34 ± 10.52 in the EPA and placebo groups, respectively (p = 0.015). Per-protocol analysis showed a decrease in scores to 18.01 ± 10.63 in the EPA group and to 30.11 ± 9.58 in the placebo group (p = 0.001). After 2 weeks, corticosteroid was needed in 11 (50.0%) patients in the EPA group and 14 (58.3%) patients in the placebo group (p = 0.571), and after 4 weeks, it was needed in 7 (33.3%) patients in the EPA group and 14 (63.6%) patients in the placebo group, respectively (p = 0.047).

CONCLUSIONS

Our results show significant favorable effects of EPA on the SCORAD scale and with regard to the necessity for corticosteroid readministration. Few adverse effects were reported in the 2 groups. We conclude that EPA supplementation is a well-tolerated and effective add-on strategy for reducing the severity of atopic dermatitis in children.

A review on the role of fatty acids in colorectal cancer progression

Colorectal cancer (CRC) is the third leading cause of mortality in cancer patients. The role of fatty acids (FA) and their metabolism in cancer, particularly in CRC raises a growing interest. In particular, dysregulation of synthesis, desaturation, elongation, and mitochondrial oxidation of fatty acids are involved. Here we review the current evidence on the link between cancer, in particular CRC, and fatty acids metabolism, not only to provide insight on its pathogenesis, but also on the development of novel biomarkers and innovative pharmacological therapies that are based on FAs dependency of cancer cells.

Habitual fish oil supplementation and incident chronic obstructive pulmonary disease: Data from a prospective cohort study

BACKGROUND

Fish oil is one of the most popular supplements in the UK and other developed countries. However, the relationship between fish oil use and chronic obstructive pulmonary disease (COPD) is unclear.

OBJECTIVE

To prospectively examine the association of habitual fish oil supplementation with incident COPD risk and to evaluate potential effect modification by genetic predisposition.

METHODS

This study included 484,414 participants (mean and standard deviation [SD] age: 56.5 [8.1] years) from the UK Biobank who completed a touchscreen questionnaire on habitual fish oil supplement use between 2006 and 2010 and were followed up through 2018. Cox regression models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) with adjustment for sociodemographic and lifestyle behaviours, health conditions, and other potential confounding factors. A weighted genetic risk score (GRS) for COPD was derived from 112 validated single nucleotide polymorphisms.

RESULTS

During a median follow-up of 9.0 years, 8860 incident COPD events were recorded. A total of 31.4% (152,230) of the study participants reported habitual fish oil supplementation at baseline. Habitual fish oil supplementation was significantly associated with a lower risk of incident COPD (adjusted HR: 0.88; 95% CI: 0.84-0.93). The association with COPD did not differ by GRS strata (P for interaction = 0.880). The results from subgroup and sensitivity analyses supported the robustness of our findings.

CONCLUSIONS

Our findings suggest that habitual fish oil supplementation is associated with a lower risk of incident COPD, irrespective of genetic predisposition.

Emerging roles of fatty acid metabolism in cancer and their targeted drug development

Metabolic reprogramming is now considered as one of hallmark of tumor cells and provides them with a selective survival/growth advantage to resist harsh micro-environmental stress. Fatty acid (FA) metabolism of tumor cells supports the biosynthetic needs and provides fuel sources for energy supply. Since FA metabolic reprogramming is a critical link in tumor metabolism, its various roles in tumors have attracted increasing interest. Herein, we review the mechanisms through which cancer cells rewire their FA metabolism with a focus on the pathway of FA metabolism and its targeting drug development. The failure and successful cases of targeting tumor FA metabolism are expected to bypass the metabolic vulnerability and improve the efficacy of targeted therapy.

Long-Chain Polyunsaturated Fatty Acid Status at Birth and Development of Childhood Allergy: A Systematic Review

The associations of fetal fatty acids status to immune-related health parameters later in life are unclear. Our aim is to collect all available information on the relationship between fatty acid status at birth and allergy in childhood. Systematic literature search was performed on Ovid MEDLINE, Cochrane Library, and Embase. The search retrieved 897 articles without duplicates; 14 articles remained after excluding those that did not fit into our inclusion criteria. When the dichotomous parameter of suffering or not from allergic condition in childhood was analyzed, cord blood eicosapentaenoic acid (EPA) values proved to be significantly lower in allergic than non-allergic children in four comparisons from three studies. When the linear parameters of odds ratios and relative risks for allergy were taken into consideration, high cord blood EPA, but also high docosahexaenoic acid (DHA) and high total n-3 long-chain polyunsaturated fatty acid values were associated to clinically relevant reduction (at least 38%) in eight comparisons from five studies. Within the cord blood samples, higher EPA, docosapentaenoic acid, and DHA values were significantly and negatively associated in eight correlation analyses from three studies with laboratory parameters considered to reflect allergic trait. The data reported here may provide information for defining optimal fatty acid intakes for pregnant women.

Inhalation of nebulized omega-3 fatty acids mitigate LPS-induced acute lung inflammation in rats: Implications for treatment of COPD and COVID-19

Many current treatment options for lung inflammation and thrombosis come with unwanted side effects. The natural omega-3 fatty acids (O3FA) are generally anti-inflammatory and antithrombotic. O3FA are always administered orally and occasionally by intravenous (IV) infusion. The main goal of this study is to determine if O3FA administered by inhalation of a nebulized formulation mitigates LPS-induced acute lung inflammation in male Wistar rats. Inflammation was triggered by intraperitoneal injection of LPS once a day for 14 days. One hour post-injection, rats received nebulized treatments consisting of egg lecithin emulsified O3, Budesonide and Montelukast, and blends of O3 and Melatonin or Montelukast or Cannabidiol; O3 was in the form of free fatty acids for all groups except one group with ethyl esters. Lung histology and cytokines were determined in n = 3 rats per group at day 8 and day 15. All groups had alveolar histiocytosis severity scores half or less than that of the disease control (Cd) treated with LPS and saline only inhalation. IL-6, TNF-α, TGF-β, and IL-10 were attenuated in all O3FA groups. IL-1β was attenuated in most but not all O3 groups. O3 administered as ethyl ester was overall most effective in mitigating LPS effects. No evidence of lipid pneumonia or other chronic distress was observed. These preclinical data suggest that O3FA formulations should be further investigated as treatments in lung inflammation and thrombosis related lung disorders, including asthma, chronic obstructive pulmonary disease, lung cancer and acute respiratory distress such as COVID-19.

Integrative genetics-metabolomics analysis of infant bronchiolitis-childhood asthma link: A multicenter prospective study

Background

Infants with bronchiolitis are at high risk for developing childhood asthma. While genome-wide association studies suggest common genetic susceptibilities between these conditions, the mechanisms underlying the link remain unclear.

Objective

Through integrated genetics-metabolomics analysis in this high-risk population, we sought to identify genetically driven metabolites associated with asthma development and genetic loci associated with both these metabolites and asthma susceptibility.

Methods

In a multicenter prospective cohort study of infants hospitalized for bronchiolitis, we profiled the nasopharyngeal metabolome and genotyped the whole genome at hospitalization. We identified asthma-related metabolites from 283 measured compounds and conducted metabolite quantitative trait loci (mtQTL) analyses. We further examined the mtQTL associations by testing shared genetic loci for metabolites and asthma using colocalization analysis and the concordance between the loci and known asthma-susceptibility genes.

Results

In 744 infants hospitalized with bronchiolitis, 28 metabolites (e.g., docosapentaenoate [DPA], 1,2-dioleoyl-sn-glycero-3-phosphoglycerol, sphingomyelin) were associated with asthma risk. A total of 349 loci were associated with these metabolites-161 for non-Hispanic white, 120 for non-Hispanic black, and 68 for Hispanics. Of these, there was evidence for 30 shared loci between 16 metabolites and asthma risk (colocalization posterior probability ≥0.5). The significant SNPs within loci were aligned with known asthma-susceptibility genes (e.g., ADORA1, MUC16).

Conclusion

The integrated genetics-metabolomics analysis identified genetically driven metabolites during infancy that are associated with asthma development and genetic loci associated with both these metabolites and asthma susceptibility. Identifying these metabolites and genetic loci should advance research into the functional mechanisms of the infant bronchiolitis-childhood asthma link.

Anti-Inflammatory Function of Fatty Acids and Involvement of Their Metabolites in the Resolution of Inflammation in Chronic Obstructive Pulmonary Disease

Lipid metabolism plays an important role in many lung functions. Disorders of lipid metabolism are part of the pathogenesis of chronic obstructive pulmonary disease (COPD). Lipids are involved in numerous cross-linkages with inflammation. Recent studies strongly support the involvement of fatty acids as participants in inflammation. They are involved in the initiation and resolution of inflammation, including acting as a substrate for the formation of lipid mediators of inflammation resolution. Specialized pro-inflammatory mediators (SPMs) belonging to the classes of lipoxins, resolvins, maresins, and protectins, which are formed enzymatically from unsaturated fatty acids, are now described. Disorders of their production and function are part of the pathogenesis of COPD. SPMs are currently the subject of active research in order to find new drugs. Short-chain fatty acids are another important participant in metabolic and immune processes, and their role in the pathogenesis of COPD is of great clinical interest.

Nutraceuticals: unlocking newer paradigms in the mitigation of inflammatory lung diseases

Persistent respiratory tract inflammation contributes to the pathogenesis of various chronic respiratory diseases, such as asthma, chronic obstructive pulmonary disease, and pulmonary fibrosis. These inflammatory respiratory diseases have been a major public health concern as they are the leading causes of worldwide mortality and morbidity, resulting in heavy burden on socioeconomic growth throughout these years. Although various therapeutic agents are currently available, the clinical applications of these agents are found to be futile due to their adverse effects, and most patients remained poorly controlled with a low quality of life. These drawbacks have necessitated the development of novel, alternative therapeutic agents that can effectively improve therapeutic outcomes. Recently, nutraceuticals such as probiotics, vitamins, and phytochemicals have gained increasing attention due to their nutritional properties and therapeutic potential in modulating the pathological mechanisms underlying inflammatory respiratory diseases, which could ultimately result in improved disease control and overall health outcomes. As such, nutraceuticals have been held in high regard as the possible alternatives to address the limitations of conventional therapeutics, where intensive research are being performed to identify novel nutraceuticals that can positively impact various inflammatory respiratory diseases. This review provides an insight into the utilization of nutraceuticals with respect to their molecular mechanisms targeting multiple signaling pathways involved in the pathogenesis of inflammatory respiratory diseases.

Lipid Nutrition in Asthma

Asthma is a heterogeneous pulmonary disease that has constantly increased in prevalence over the past several decades. Primary symptoms include airway constriction, airway hyperresponsiveness, and airway remodeling with additional symptoms such as shortness of breath, wheezing, and difficulty breathing. Allergic asthma involves chronic inflammation of the lungs, and the rise in its yearly diagnosis is potentially associated with the increased global consumption of foods similar to the western diet. Thus, there is growing interest into the link between diet and asthma symptoms, with mounting evidence for an important modulatory role for dietary lipids. Lipids can act as biological mediators in both a proinflammatory and proresolution capacity. Fatty acids play key roles in signaling and in the production of mediators in the allergic and inflammatory pathways. The western diet leads to a disproportionate ω-6:ω-3 ratio, with drastically increased ω-6 levels. To counteract this, consumption of fish and fish oil and the use of dietary oils with anti-inflammatory properties such as olive and sesame oil can increase ω-3 and decrease ω-6 levels. Increasing vitamin intake, lowering LDL cholesterol levels, and limiting consumption of oxidized lipids can help reduce the risk of asthma and the exacerbation of asthmatic symptoms. These dietary changes can be achieved by increasing intake of fruits, vegetables, nuts, oily fish, seeds, animal-related foods (eggs, liver), cheeses, grains, oats, and seeds, and decreasing consumption of fried foods (especially fried in reused oils), fast foods, and heavily processed foods.

Associations between plasma levels of omega-3 fatty acids and subsequent allergic diseases

BACKGROUND

Some metabolites of omega-3 fatty acids, such as Maresin have been reported as inflammation converging substances and are suspected to be related to various inflammatory diseases. However, limited number of clinical researches on the association between omega-3 fatty acid as blood levels and inflammatory diseases were published.

METHODS

We conducted a retrospective cohort study at St. Luke's International Hospital from January 2007 to December 2017. We included all adult patients who had measured plasma fatty acids levels as a part of clinical practice. We excluded patients who had a prior medical history of any allergic diseases. Our primary outcomes were the development of any allergic diseases. The outcomes were compared with Cox proportional hazard model between patients quartered by baseline plasma levels of n-3 PUFAs, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) adjusting for potential confounders.

RESULTS

A total of 1506 patients were included. The mean age was 63.3 (SD: 12.5) years and 1066 (70.8%) were male. The mean EPA levels were 84.09 (SD: 58.67) μg/ml and DHA levels were 139.61 (SD: 60.47) μg/ml. Neither EPA nor DHA levels were significantly associated with the development of allergic disease (log-rank test; p = 0.933, p = 0.908, respectively) in bivariable analyses, or multivariable analyses (hazard ratios [HRs]: 0.90-0.97 for EPA; and HRs: 0.89-0.90 for DHA).

CONCLUSIONS

The EPA and DHA levels were related to C-reactive protein (CRP) of inflammation maker, but non-significant associated with development allergic diseases.

Lipid metabolism in asthma: Immune regulation and potential therapeutic target

Asthma is a chronic inflammatory disease of the lungs that poses a considerable health and socioeconomic burden. Several risk factors work synergistically to affect the progression of asthma. Lipid metabolism, especially in distinct cells such as T cells, macrophages, granulocytes, and non-immune cells, plays an essential role in the pathogenesis of asthma, as lipids are potent signaling molecules that regulate a multitude of cellular response. In this review, we focused on the metabolic pathways of lipid molecules, especially fatty acids and their derivatives, and summarized their roles in various cells during the pathogenesis of asthma along with the current pharmacological agents targeting lipid metabolism.

IgE-Mediated Fish Allergy in Children

Fish allergy constitutes a severe problem worldwide. Its prevalence has been calculated as high as 7% in paediatric populations, and in many cases, it persists into adulthood with life-threatening signs and symptoms. The following review focuses on the epidemiology of Immunoglobulin E (IgE)-mediated fish allergy, its pathogenesis, clinical manifestations, and a thorough approach to diagnosis and management in the paediatric population. The traditional approach for managing fish allergy is avoidance and rescue medication for accidental exposures. Food avoidance poses many obstacles and is not easily maintained. In the specific case of fish, food is also not the only source of allergens; aerosolisation of fish proteins when cooking is a common source of highly allergenic parvalbumin, and elimination diets cannot prevent these contacts. Novel management approaches based on immunomodulation are a promising strategy for the future of these patients.

Omega-3 Fatty Acids for Sport Performance-Are They Equally Beneficial for Athletes and Amateurs? A Narrative Review

Omega-3 fatty acids, specifically eicosapentanoic acid (EPA, 20:5n-3) and docosahexanoic acid (DHA, 22:6n-3) are receiving increasing attention in sports nutrition. While the usual focus is that of athletes, questions remain if the different training status between athletes and amateurs influences the response to EPA/DHA, and as to whether amateurs would benefit from EPA/DHA supplementation. We critically examine the efficacy of EPA/DHA on performance, recovery and injury/reduced risk of illness in athletes as well as amateurs. Relevant studies conducted in amateurs will not only broaden the body of evidence but shed more light on the effects of EPA/DHA in professionally trained vs. amateur populations. Overall, studies of EPA/DHA supplementation in sport performance are few and research designs rather diverse. Several studies suggest a potentially beneficial effect of EPA/DHA on performance by improved endurance capacity and delayed onset of muscle soreness, as well as on markers related to enhanced recovery and immune modulation. The majority of these studies are conducted in amateurs. While the evidence seems to broadly support beneficial effects of EPA/DHA supplementation for athletes and more so in amateurs, strong conclusions and clear recommendations about the use of EPA/DHA supplementation are currently hampered by inconsistent translation into clinical endpoints.

Allergy Modulation by N-3 Long Chain Polyunsaturated Fatty Acids and Fat Soluble Nutrients of the Mediterranean Diet

The Mediterranean diet, containing valuable nutrients such as n-3 long chain poly-unsaturated fatty acids (LCPUFAs) and other fat-soluble micronutrients, is known for its health promoting and anti-inflammatory effects. Its valuable elements might help in the battle against the rising prevalence of non-communicable diseases (NCD), including the development of allergic diseases and other (chronic) inflammatory diseases. The fat fraction of the Mediterranean diet contains bioactive fatty acids but can also serve as a matrix to dissolve and increase the uptake of fat-soluble vitamins and phytochemicals, such as luteolin, quercetin, resveratrol and lycopene with known immunomodulatory and anti-inflammatory capacities. Especially n-3 LCPUFAs such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) derived from marine oils can target specific receptors or signaling cascades, act as eicosanoid precursors and/or alter membrane fluidity and lipid raft formation, hereby exhibiting anti-inflammatory properties. Beyond n-3 LCPUFAs, fat-soluble vitamins A, D, E, and K1/2 have the potential to affect pro-inflammatory signaling cascades by interacting with receptors or activating/inhibiting signaling proteins or phosphorylation in immune cells (DCs, T-cells, mast cells) involved in allergic sensitization or the elicitation/effector phase of allergic reactions. Moreover, fat-soluble plant-derived phytochemicals can manipulate signaling cascades, mostly by interacting with other receptors or signaling proteins compared to those modified by fat-soluble vitamins, suggesting potential additive or synergistic actions by applying a combination of these nutrients which are all part of the regular Mediterranean diet. Research concerning the effects of phytochemicals such as polyphenols has been hampered due to their poor bio-availability. However, their solubility and uptake are improved by applying them within the dietary fat matrix. Alternatively, they can be prepared for targeted delivery by means of pharmaceutical approaches such as encapsulation within liposomes or even unique nanoparticles. This review illuminates the molecular mechanisms of action and possible immunomodulatory effects of n-3 LCPUFAs and fat-soluble micronutrients from the Mediterranean diet in allergic disease development and allergic inflammation. This will enable us to further appreciate how to make use of the beneficial effects of n-3 LCPUFAs, fat-soluble vitamins and a selection of phytochemicals as active biological components in allergy prevention and/or symptom reduction.

Metabolic profiling of organic and fatty acids in chronic and autoimmune diseases

Metabolomics is a powerful tool of omics that permits the simultaneous identification of metabolic perturbations in several autoimmune and chronic diseases. Several parameters can affect a metabolic profile, from the population characteristics to the selection of the analytical method. In the current chapter, we summarize the main analytical methods and results of the metabolic profiling of fatty and organic acids performed in human metabolomic studies for asthma, COPD, psoriasis and Hashimoto's thyroiditis. We discuss the most significant metabolic alterations associated with these diseases, after comparison of either a single patient's group with healthy controls or several patient's subgroups of different disease severity and phenotype with healthy controls or of a patient's group before and after treatment. Finally, we present critical metabolic patterns that are associated with each disease and their potency for the unraveling of disease pathogenesis, prediction, diagnosis, patient stratification and treatment selection.

Lipid mediators and asthma: Scope of therapeutics

Lipids and their mediators are known to play a pro-inflammatory role in several human diseases including asthma. The influence of leukotrienes and prostaglandins through arachidonate metabolism in asthma pathophysiology is well established and hence, prompted the way for therapeutic strategies targeting lipid metabolites. In addition, various types of fatty acids have been reported to play a diverse role in asthma. For instance, CD4⁺ T-lymphocytes differentiation towards T-effector (T_eff) or T-regulatory (Tregs) cells seems to be controlled reciprocally by fatty acid metabolic pathways. Further, the dysregulated lipid status in obesity complicates the asthma manifestations suggesting the role of lipid metabolites particularly ω-6 fatty acids in the process. On the other hand, clinical and pre-clinical studies suggests the role of short chain fatty acids in curbing asthma through upregulation of T-regulatory cells or clearance of inflammatory cells through promoting apoptosis. Accordingly, the present review compiles various studies for comprehensive analysis of different types of lipid based metabolites in asthma manifestation. Finally, we have proposed certain strategies which may enhance the usefulness of lipid mediators for balanced immune response during asthma.

Reprogramming of fatty acid metabolism in cancer

A common feature of cancer cells is their ability to rewire their metabolism to sustain the production of ATP and macromolecules needed for cell growth, division and survival. In particular, the importance of altered fatty acid metabolism in cancer has received renewed interest as, aside their principal role as structural components of the membrane matrix, they are important secondary messengers, and can also serve as fuel sources for energy production. In this review, we will examine the mechanisms through which cancer cells rewire their fatty acid metabolism with a focus on four main areas of research. (1) The role of de novo synthesis and exogenous uptake in the cellular pool of fatty acids. (2) The mechanisms through which molecular heterogeneity and oncogenic signal transduction pathways, such as PI3K-AKT-mTOR signalling, regulate fatty acid metabolism. (3) The role of fatty acids as essential mediators of cancer progression and metastasis, through remodelling of the tumour microenvironment. (4) Therapeutic strategies and considerations for successfully targeting fatty acid metabolism in cancer. Further research focusing on the complex interplay between oncogenic signalling and dysregulated fatty acid metabolism holds great promise to uncover novel metabolic vulnerabilities and improve the efficacy of targeted therapies.

Pro-Resolving Lipid Mediators in the Pathophysiology of Asthma

Asthma is one of the most important medical and social problems of our time due to the prevalence and the complexity of its treatment. Chronic inflammation that is characteristic of asthma is accompanied by bronchial obstruction, which involves various lipid mediators produced from n-6 and n-3 polyunsaturated fatty acids (PUFAs). The review is devoted to modern ideas about the PUFA metabolites—eicosanoids (leukotrienes, prostaglandins, thromboxanes) and specialized pro-resolving lipid mediators (SPMs) maresins, lipoxins, resolvins, protectins. The latest advances in clinical lipidomics for identifying and disclosing the mechanism of synthesis and the biological action of SPMs have been given. The current views on the peculiarities of the inflammatory reaction in asthma and the role of highly specialized metabolites of arachidonic, eicosapentaenoic and docosahexaenoic acids in this process have been described. The possibility of using SPMs as therapeutic agents aimed at controlling the resolution of inflammation in asthma is discussed.