Omega-3 fatty acids in contrast to omega-6 protect against pneumococcal pneumonia

Eicosapentaenoic Acid and Docosahexaenoic Acid as an Antimicrobial Agent in Orthopedics-An In Vitro Study About the Race for Surface

BACKGROUND

The burden of prosthetic joint infection in combination with antibiotic-resistant bacterial strains is a rising dilemma for patients experiencing total joint replacements. Around 0.8-2% of patients experience prosthetic joint infections, while up to 21% of patients are considered fatal cases after 5 years. Staphylococcus aureus is one of the main reasons for prosthetic joint infections. Its capability of forming biofilms and developing mechanisms against antibiotics is one of the most dangerous clinical topics being currently discussed. Previous studies have shown the promising results of omega-3 fatty acids as an antimicrobial agent against Staphylococcus aureus. Though an antimicrobial effect has been examined, the influence of polyunsaturated fatty acids on Staphylococcus aureus in the presence of human osteoblasts has not been reported yet. In this study, we aimed to investigate the influence of omega-3 fatty acids on the biofilm formation of Staphylococcus aureus ATCC 29213 in the presence of hFOB 1.19 cells. The co-culture setup helped to examine the influence of omega-3 fatty acids on the race for surface to simulate prosthetic joint infections.

METHODS

In this study, we tested Staphylococcus aureus ATCC 29213 co-cultured with human fetal osteoblasts hFOB 1.19 in the presence of sub-MIC and MIC concentrations of docosahexaenoic acid (1.25 mg/L, 2.5 mg/L) and eicosapentaenoic acid (0.15 mg/L, 0.3 mg/L) after 1, 6 and 24 h of incubation. After establishing the co-culture, cell culture and biofilm, we performed colony-forming unit counting and cell counting to examine cell survivability. In addition, we carried out scanning electron microscopy to study the race for surface behaviour of the cells.

RESULTS

We found a protective influence of omega-3 fatty acids on osteoblasts when present in co-culture with Staphylococcus aureus after 6 h of incubation. Omega-3 fatty acids increase the cell survival of osteoblasts after 6 h in a co-culture with bacteria and are able to influence the race for surface. In this study, the strain of Staphylcoccus aureus ATCC 29213 showed signs of growth inhibition within the first 6 h.

CONCLUSIONS

Omega-3 fatty acids can be a valuable antimicrobial agent in terms of decreasing the risk of on-site infection during surgery. Omega-3 fatty acids were shown to decrease the bacterial load within the first 6 h of incubation and increase the survivability of osteoblasts.

Omega-3 long-chain polyunsaturated fatty acids and their bioactive lipids: A strategy to improve resistance to respiratory tract infectious diseases in the elderly?

Age-related changes in organ function, immune dysregulation, and the effects of senescence explain in large part the high prevalence of infections, including respiratory tract infections in older persons. Poor nutritional status in many older persons increases susceptibility to infection and worsens prognosis. Interestingly, there is an association between the amount of saturated fats in the diet and the rate of community-acquired pneumonia. Polyunsaturated fatty acids, particularly omega-3 long chain polyunsaturated fatty acids (ω-3 LC-PUFAs) including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have well-known anti-inflammatory, immunomodulatory, and antimicrobial effects, which may, in theory, be largely induced by PUFAs-derived lipids such as specialized pro-resolving mediators (SPMs). In adults, preliminary results of studies show that ω-3 LC-PUFAs supplementation can lead to SPM generation. SPMs have a crucial role in the resolution of inflammation, a factor relevant to survival from infection independent of the pathogen’s virulence. Moreover, the immune system of older adults appears to be more sensitive to ω-3 PUFAs. This review explores the effects of ω-3 LC-PUFAs, and PUFA bioactive lipid-derived SPMs in respiratory tract infections and the possible relevance of these data to infectious disease outcomes in the older population. The hypothesis that PUFAs have beneficial effects via SPM generation will need to be confirmed by animal experiments and patient-derived data.

Lipidomic and metabolomic changes in community-acquired and COVID-19 pneumonia

This prospective observational study compared the 1H NMR blood lipidomes and metabolomes of 71 patients with community-acquired pneumonia (CAP), 75 patients with COVID-19 pneumonia, and 75 healthy controls (matched by age and sex) to identify potential biomarkers and pathways associated with respiratory infections. Both pneumonia groups had comparable severity indices, including mortality, invasive mechanical ventilation, and intensive care unit admission rates. Patients with COVID-19 pneumonia exhibited more pronounced hypolipidemia, with significantly lower levels of total cholesterol and LDL-c compared to patients with CAP. Atherogenic lipoprotein subclasses (VLDL-cholesterol, IDL-cholesterol, IDL-triglyceride, and LDL-triglyceride/LDL-cholesterol) were significantly increased in severe cases of both pneumonia types, while lower HDL-c and small, dense HDL particles were associated with more severe illness. Both infected groups showed decreased esterified cholesterol and increased triglycerides, along with reduced phosphatidylcholine, lysophosphatidylcholine, PUFA, omega-3 fatty acids, and DHA. Additionally, infected patients had elevated levels of glucose, lactate, 3-hydroxybutyrate, and acetone, which are linked to inflammation, hypoxemia, and sepsis. Increased levels of branched-chain amino acids, alanine, glycine, and creatine, which are involved in energy metabolism and protein catabolism, were also observed. Neurotransmitter synthesis metabolites like histidine and glutamate were higher in infected patients, especially those with COVID-19. Notably, severe infections showed a significant decrease in glutamine, essential for lymphocyte and macrophage energy. The severity of COVID-19 pneumonia was also associated with elevated glycoprotein levels (glycoprotein A, glycoprotein B, and glycoprotein F), indicating an inflammatory state. These findings suggest that metabolomic and lipidomic changes in pneumonia are connected to bioenergetic pathways regulating the immune response.

Metformin Attenuates Inflammatory Responses and Enhances Antibody Production in an Acute Pneumonia Model of Streptococcus pneumoniae

Metformin may potentially reverse various age-related conditions; however, it is unclear whether metformin can also mitigate or delay the deterioration of immunological resilience that occurs in the context of infections that are commonly observed in older persons. We examined whether metformin promotes the preservation of immunological resilience in an acute S. pneumoniae (SPN) infection challenge in young adult mice. Mice were fed metformin (MET-alone) or standard chow (controls-alone) for 10 weeks prior to receiving intratracheal inoculation of SPN. A subset of each diet group received pneumococcal conjugate vaccine at week 6 (MET + PCV and control + PCV). Compared to controls-alone, MET-alone had significantly less infection-associated morbidity and attenuated inflammatory responses during acute SPN infection. Metformin lowered the expression of genes in the lungs related to inflammation as well as shorter lifespan in humans. This was accompanied by significantly lower levels of pro-inflammatory cytokines (e.g., IL6). MET + PCV vs. control + PCV manifested enhanced SPN anticapsular IgM and IgG levels. The levels of SPN IgM production negatively correlated with expression levels of genes linked to intestinal epithelial structure among MET + PCV vs. control + PCV groups. Correspondingly, the gut microbial composition of metformin-fed mice had a significantly higher abundance in the Verrucomicrobia, Akkermansia muciniphila, a species previously associated with beneficial effects on intestinal integrity and longevity. Together, these findings indicate metformin's immunoprotective potential to protect against infection-associated declines in immunologic resilience.

Alterations of Lipid Profile in COVID-19: A Narrative Review

The COVID-19 pandemic has led to over 100 million infections and over 3 million deaths worldwide. Understanding its pathogenesis is crucial to guide prognostic and therapeutic implications. Viral infections are known to alter the lipid profile and metabolism of their host cells, similar to the case with MERS and SARS-CoV-2002. Since lipids play various metabolic roles, studying lipid profile alterations in COVID-19 is an inevitable step as an attempt to achieve better therapeutic strategies, as well as a potential prognostic factor in the course of this disease. Several studies have reported changes in lipid profile associated with COVID-19. The most frequently reported changes are a decline in serum cholesterol and ApoA1 levels and elevated triglycerides. The hyper-inflammatory state mediated by the Cytokine storm disturbs several fundamental lipid biosynthesis pathways. Virus replication is a process that drastically changes the host cell's lipid metabolism program and overuses cell lipid resources. Lower HDL-C and ApoA1 levels are associated with higher severity and mortality rates and with higher levels of inflammatory markers. Studies suggest that arachidonic acid omega-3 derivatives might help modulate hyper-inflammation and cytokine storm resulting from pulmonary involvement. Also, statins have been shown to be beneficial when administered after COVID-19 diagnosis via unclear mechanisms probably associated with anti-inflammatory effects and HDL-C rising effects.

Immunomodulatory Role of Nutrients: How Can Pulmonary Dysfunctions Improve?

Nutrition is an important tool that can be used to modulate the immune response during infectious diseases. In addition, through diet, important substrates are acquired for the biosynthesis of regulatory molecules in the immune response, influencing the progression and treatment of chronic lung diseases, such as asthma and chronic obstructive pulmonary disease (COPD). In this way, nutrition can promote lung health status. A range of nutrients, such as vitamins (A, C, D, and E), minerals (zinc, selenium, iron, and magnesium), flavonoids and fatty acids, play important roles in reducing the risk of pulmonary chronic diseases and viral infections. Through their antioxidant and anti-inflammatory effects, nutrients are associated with better lung function and a lower risk of complications since they can decrease the harmful effects from the immune system during the inflammatory response. In addition, bioactive compounds can even contribute to epigenetic changes, including histone deacetylase (HDAC) modifications that inhibit the transcription of proinflammatory cytokines, which can contribute to the maintenance of homeostasis in the context of infections and chronic inflammatory diseases. These nutrients also play an important role in activating immune responses against pathogens, which can help the immune system during infections. Here, we provide an updated overview of the roles played by dietary factors and how they can affect respiratory health. Therefore, we will show the anti-inflammatory role of flavonoids, fatty acids, vitamins and microbiota, important for the control of chronic inflammatory diseases and allergies, in addition to the antiviral role of vitamins, flavonoids, and minerals during pulmonary viral infections, addressing the mechanisms involved in each function. These mechanisms are interesting in the discussion of perspectives associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and its pulmonary complications since patients with severe disease have vitamins deficiency, especially vitamin D. In addition, researches with the use of flavonoids have been shown to decrease viral replication in vitro. This way, a full understanding of dietary influences can improve the lung health of patients.

Molecular Mechanisms of Palmitic Acid Augmentation in COVID-19 Pathologies

The coronavirus disease 2019 (COVID-19) pandemic has claimed over 2.7 million lives globally. Obesity has been associated with increased severity and mortality of COVID-19. However, the molecular mechanisms by which obesity exacerbates COVID-19 pathologies are not well-defined. The levels of free fatty acids (FFAs) are elevated in obese subjects. This study was therefore designed to examine how excess levels of different FFAs may affect the progression of COVID-19. Biological molecules associated with palmitic acid (PA) and COVID-19 were retrieved from QIAGEN Knowledge Base, and Ingenuity Pathway Analysis tools were used to analyze these datasets and explore the potential pathways affected by different FFAs. Our study found that one of the top 10 canonical pathways affected by PA was the coronavirus pathogenesis pathway, mediated by key inflammatory mediators, including PTGS2; cytokines, including IL1β and IL6; chemokines, including CCL2 and CCL5; transcription factors, including NFκB; translation regulators, including EEF1A1; and apoptotic mediators, including BAX. In contrast, n-3 fatty acids may attenuate PA's activation of the coronavirus pathogenesis pathway by inhibiting the activity of such mediators as IL1β, CCL2, PTGS2, and BAX. Furthermore, PA may modulate the expression of ACE2, the main cell surface receptor for the SARS-CoV-2 spike protein.

Dietary Supplementation With Eicosapentaenoic Acid Inhibits Plasma Cell Differentiation and Attenuates Lupus Autoimmunity

Accumulating evidence suggests that cholesterol accumulation in leukocytes is causally associated with the development of autoimmune diseases. However, the mechanism by which fatty acid composition influences autoimmune responses remains unclear. To determine whether the fatty acid composition of diet modulates leukocyte function and the development of systemic lupus erythematosus, we examined the effect of eicosapentaenoic acid (EPA) on the pathology of lupus in drug-induced and spontaneous mouse models. We found that dietary EPA supplementation ameliorated representative lupus manifestations, including autoantibody production and immunocomplex deposition in the kidneys. A combination of lipidomic and membrane dynamics analyses revealed that EPA remodels the lipid composition and fluidity of B cell membranes, thereby preventing B cell differentiation into autoantibody-producing plasma cells. These results highlight a previously unrecognized mechanism by which fatty acid composition affects B cell differentiation into autoantibody-producing plasma cells during autoimmunity, and imply that EPA supplementation may be beneficial for therapy of lupus.

Correlation between bioactive lipids and novel coronavirus: constructive role of biolipids in curbing infectivity by enveloped viruses, centralizing on EPA and DHA

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) belongs to the family coronaviridae. It is spherical and possesses proteins called spikes, which can clamp onto the human cells. Once in close interaction with the human cells, these viruses undergo structural change and can fuse with the cell membrane. The virus enters the host and starts the process of translation and transcription in the cells and uncoated genome, respectively. Due to the rapid transmittable nature of the virus, extant actions should be taken. The fatty acids administrated orally, or intravenously, could help us gear things up in providing resistance and preventing infection. Hence, the multiplication of the virus could be hindered by arachidonic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). In that context, the current review highlights the role of these unsaturated fatty acids and their derivatives such as lipoxins and resolvins in the inactivation of the enveloped coronavirus disease 2019 (COVID-19).

Micronutrients, Phytochemicals and Mediterranean Diet: A Potential Protective Role against COVID-19 through Modulation of PAF Actions and Metabolism

The new coronavirus disease 2019 (COVID-19) pandemic is an emerging situation with high rates of morbidity and mortality, in the pathophysiology of which inflammation and thrombosis are implicated. The disease is directly connected to the nutritional status of patients and a well-balanced diet is recommended by official sources. Recently, the role of platelet activating factor (PAF) was suggested in the pathogenesis of COVID-19. In the present review several micronutrients (vitamin A, vitamin C, vitamin E, vitamin D, selenium, omega-3 fatty acids, and minerals), phytochemicals and Mediterranean diet compounds with potential anti-COVID activity are presented. We further underline that the well-known anti-inflammatory and anti-thrombotic actions of the investigated nutrients and/or holistic dietary schemes, such as the Mediterranean diet, are also mediated through PAF. In conclusion, there is no single food to prevent coronavirus Although the relationship between PAF and COVID-19 is not robust, a healthy diet containing PAF inhibitors may target both inflammation and thrombosis and prevent the deleterious effects of COVID-19. The next step is the experimental confirmation or not of the PAF-COVID-19 hypothesis.

May omega-3 fatty acid dietary supplementation help reduce severe complications in Covid-19 patients?

In around 10% of SARS-CoV-2 infected patients, coronavirus disease-2019 (Covid-19) symptoms are complicated with a severe lung damage called Acute Respiratory Distress Syndrome (ARDS), which is often lethal. ARDS is mainly associated with an uncontrolled overproduction of immune cells and cytokines, called "cytokine storm syndrome"; it appears 7-15 days following the onset of symptoms, leading to systemic inflammation and multiple organ failure. Because they are well-known metabolic precursors of specialized pro-resolving lipid mediators (SPMs), omega-3 long-chain polyunsaturated fatty acids (omega-3 LC-PUFAs) could help improve the resolution of the inflammatory balance, limiting therefore the level and duration of the critical inflammatory period. Omega-3 LC-PUFAs may also interact at different stages of the viral infection, notably on the virus entry and replication. In the absence of demonstrated treatment and while waiting for vaccine possibility, the use of omega-3 LC-PUFAs deserve therefore to be considered, based on previous clinical studies suggesting that omega-3 supplementation could improve clinical outcomes of critically ill patients at the acute phase of ARDS. In this context, it is crucial to remind that the omega-3 PUFA dietary intake levels in Western countries remains largely below the current recommendations, considering both the omega-3 precursor α-linolenic acid (ALA) and long chain derivatives such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). An optimized omega-3 PUFAs status could be helpful to prevent infectious diseases, including Covid-19.