The 2008 ESPEN Sir David Cuthbertson Lecture: Fatty acids and inflammation--from the membrane to the nucleus and from the laboratory bench to the clinic

A Novel Comprehensive Therapeutic Approach to the Challenges of Chronic Wounds: A Brief Review and Clinical Experience Report

Following the clinical perspective and concept that a healthy body will not develop chronic wounds, the central approach for the treatment described here is based on an understanding of how the body transforms the wound microenvironment from a non-healing to a healing state. As part of a comprehensive treatment regimen that includes OCM™ (complete matrix), wound preparation, and skin protectant formulations, the OCM contains components for complete wound healing by attending to the individual needs required to promote the closure of each unique chronic wound. During application of the comprehensive treatment regimen in independent investigator-led trials, the total wound percentage average reduction over the first 4 weeks of treatment was 60% across multiple wound types; median time to total wound closure was 6.9 weeks. Safety testing of the OCM formulation shows no potential allergenicity, no potential sensitization, and no known product-related adverse events. Clinical trials evaluating the OCM formulation as part of the comprehensive treatment regimen of multiple wound types are underway. Results of clinical trials and real-world experiences will expand current knowledge of the wound-healing potential of this novel product.

Designing blenderized tube feeding diets for children and investigating their physicochemical and microbial properties and Dietary Inflammatory Index

BACKGROUND

Due to the benefits of blenderized tube feeding (BTF) diets, the interest in using them is increasing. This study aimed to design BTFs for children and investigate their physicochemical and microbial properties, as well as Dietary Inflammatory Index (DII).

METHODS

Five BTF diets were formulated mainly with fresh foods; their DII, physical (viscosity), and chemical (moisture, ash, protein, fat, energy, and micronutrients) characteristics were assessed. Also, the Hazard Analysis and Critical Control Points (HACCP) system was implemented for quality assurance of preparation, storage, and delivery of BTFs to patients in hospital. The microbial contamination (total count, Salmonella, Escherichia coli, Bacillus cereus, Listeria monocytogenes, coliforms, Staphylococcus aureus coagulase positive, mold, and yeast) was analyzed.

RESULTS

Energy and percentages of protein, fat, and carbohydrate in BTFs were in the range of 103-112 kcal/100 ml, 16%-22%, 28%-34%, and 48%-52%, respectively. The viscosity of the five developed BTFs was between 29 and 64 centipoises, which allows the formulas to flow without syringe pressure. The DII of all BTFs was between -0.73 and -2.24. Due to the implementation of HACCP, monitoring the production line of BTFs, and performance of corrective measures, no microbial contamination was observed by indicator pathogenic microorganisms.

CONCLUSION

A planned BTF diet can be an excellent selection for children using enteral nutrition with tube feeding especially when they are made from fresh and anti-inflammatory foods such as recipes prepared in this study.

Life factors acting on systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a highly heterogeneous autoimmune disease that primarily affects women. Currently, in the search for the mechanisms of SLE pathogenesis, the association of lifestyle factors such as diet, cigarette smoking, ultraviolet radiation exposure, alcohol and caffeine-rich beverage consumption with SLE susceptibility has been systematically investigated. The cellular and molecular mechanisms mediating lifestyle effects on SLE occurrence, including interactions between genetic risk loci and environment, epigenetic changes, immune dysfunction, hyper-inflammatory response, and cytotoxicity, have been proposed. In the present review of the reports published in reputable peer-reviewed journals and government websites, we consider the current knowledge about the relationships between lifestyle factors and SLE incidence and outline directions of future research in this area. Formulation of practical measures with regard to the lifestyle in the future will benefit SLE patients and may provide potential therapy strategies.

Past Experiences for Future Applications of Metabolomics in Critically Ill Patients with Sepsis and Septic Shocks

A disruption of several metabolic pathways in critically ill patients with sepsis indicates that metabolomics might be used as a more precise tool for sepsis and septic shock when compared with the conventional biomarkers. This article provides information regarding metabolomics studies in sepsis and septic shock patients. It has been shown that a variety of metabolomic pathways are altered in sepsis and septic shock, including amino acid metabolism, fatty acid oxidation, phospholipid metabolism, glycolysis, and tricarboxylic acid cycle. Based upon this comprehensive review, here, we demonstrate that metabolomics is about to change the world of sepsis biomarkers, not only for its utilization in sepsis diagnosis, but also for prognosticating and monitoring the therapeutic response. Additionally, the future direction regarding the establishment of studies integrating metabolomics with other molecular modalities and studies identifying the relationships between metabolomic profiles and clinical characteristics to address clinical application are discussed in this article. All of the information from this review indicates the important impact of metabolomics as a tool for diagnosis, monitoring therapeutic response, and prognostic assessment of sepsis and septic shock. These findings also encourage further clinical investigations to warrant its use in routine clinical settings.

Leukotriene B4 limits the effectiveness of fish oil in an animal model of asthma

This study aimed to evaluate the levels of eicosanoids derived from arachidonic acid (ARA) in the lungs of asthmatic rats supplemented with fish oil. The present data gives insight into the action of fish oil in asthma, related to its inability to modify the contractile capacity of tracheal smooth muscle reported previously in a model of asthma in rats. Male Wistar rats were supplemented daily with 1 g of fish oil/kg of body weight for 21 days. They were exposed to ovalbumin (OVA) after previous sensitization with OVA to induce asthma. Pulmonary levels of five eicosanoids were measured using immunoassay kits: PGE2, TXB2, LTB4, LXA4, and 8-iso PGF2α. In asthmatic rats, supplementation with fish oil resulted in lower concentrations of lung eicosanoids produced by cyclooxygenase-2 and 15-lipoxygenase: PGE2, TXB2, and LXA4, respectively. Fish oil supplementation also decreased the non-enzymatically produced eicosanoid 8-iso PGF2α. Fish oil supplementation did not affect LTB4, a metabolite of 5-lipoxygenase. The limited efficacy of fish oil supplementation in asthmatic rats is associated with a lack of action in reducing the levels of LTB4 in the lungs. Thus, fish oil differentially modulates the concentrations of eicosanoids derived from ARA via specific pathways in an animal model of asthma.

Serum levels of n-3 and n-6 polyunsaturated fatty acids in patients with systemic lupus erythematosus and their association with disease activity: a pilot study

Objective: Polyunsaturated fatty acids (PUFAs) may modulate the inflammatory process in systemic autoimmune diseases, including systemic lupus erythematosus (SLE). The aim of this study was to assess the serum concentrations of essential 18-carbon PUFAs and their long-chain derivatives in patients with SLE and healthy controls, and to analyse their associations with laboratory and clinical features of the disease.Method: n-6 and n-3 PUFA composition was assessed in the sera of 30 SLE patients and 20 healthy controls using gas chromatography-mass spectrometry. We investigated the associations between PUFAs and disease activity measured with Systemic Lupus Erythematosus Activity Index (SLEDAI) scores, erythrocyte sedimentation rate, C-reactive protein, complement C3 and C4 concentrations, anti-nuclear antibody (ANA) titre, anti-double-stranded DNA (anti-dsDNA) antibody concentration, and medications.Results: Serum linoleic acid (LA) and α-linolenic acid concentrations were significantly higher in SLE patients compared with healthy controls. LA concentration correlated positively with the ANA titre and corticosteroid doses; eicosapentaenoic acid (EPA) and docosahexaenoic acid correlated inversely with anti-dsDNA antibody concentration. Patients treated with immunosuppressants had significantly lower concentrations of LA, arachidonic acid, and EPA.Conclusion: Both n-6 and n-3 PUFA precursors can participate in the inflammatory process in SLE patients. The mechanism of the PUFA metabolism disturbance needs further exploration.

Immunomodulatory Effects of Diet and Nutrients in Systemic Lupus Erythematosus (SLE): A Systematic Review

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by multiple organ involvement, including the skin, joints, kidneys, lungs, central nervous system and the haematopoietic system, with a large number of complications. Despite years of study, the etiology of SLE remains unclear; thus, safe and specifically targeted therapies are lacking. In the last 20 years, researchers have explored the potential of nutritional factors on SLE and have suggested complementary treatment options through diet. This study systematically reviews and evaluates the clinical and preclinical scientific evidence of diet and dietary supplementation that either alleviate or exacerbate the symptoms of SLE. For this review, a systematic literature search was conducted using PubMed, Scopus and Google Scholar databases only for articles written in the English language. Based on the currently published literature, it was observed that a low-calorie and low-protein diet with high contents of fiber, polyunsaturated fatty acids, vitamins, minerals and polyphenols contain sufficient potential macronutrients and micronutrients to regulate the activity of the overall disease by modulating the inflammation and immune functions of SLE.

Immunosenescence and Its Hallmarks: How to Oppose Aging Strategically? A Review of Potential Options for Therapeutic Intervention

Aging is accompanied by remodeling of the immune system. With time, this leads to a decline in immune efficacy, resulting in increased vulnerability to infectious diseases, diminished responses to vaccination, and a susceptibility to age-related inflammatory diseases. An age-associated immune alteration, extensively reported in previous studies, is the reduction in the number of peripheral blood naïve cells, with a relative increase in the frequency of memory cells. These two alterations, together with inflamm-aging, are considered the hallmarks of immunosenescence. Because aging is a plastic process, it is influenced by both nutritional and pharmacological interventions. Therefore, the role of nutrition and of immunomodulation in immunosenescence is discussed, due to the multifactorial influence on these hallmarks. The close connection between nutrition, intake of bioactive nutrients and supplements, immune function, and inflammation demonstrate the key role of dietary strategies as regulators of immune response and inflammatory status, hence as possible modulators of the rate of immunosenescence. In addition, potential options for therapeutic intervention are clarified. In particular, the use of interleukin-7 as growth factor for naïve T cells, the function of checkpoint inhibitors in improving T cell responses during aging and, the potential of drugs that inhibit mitogen-activated protein kinases and their interaction with nutrient signaling pathways are discussed. Finally, it is suggested that the inclusion of appropriate combinations of toll-like receptor agonists may enhance the efficacy of vaccination in older adults.

Changes of plasma acetylcholine and inflammatory markers in critically ill patients during early enteral nutrition: A prospective observational study

BACKGROUND

Acetylcholine (Ach) is the key anti-inflammatory transmitter in the cholinergic anti-inflammatory pathway. In this study, critically ill patients treated with early enteral nutrition (EEN) were observed to explore whether EEN affected Ach levels and inflammation.

METHODS

One hundred thirteen patients were included in this prospective observational study. All patients were provided the early enteral nutrition protocol 24-48 h after admission to the intensive care unit (ICU). Blood samples were collected, and the plasma levels of Ach, cholecystokinin (CCK), and inflammatory markers (tumour necrosis factor alpha (TNF-α), interleukin 1beta (IL1-β), and IL6) were measured on Days 0, 1, 3, 5, and 7. Nutritional intervention data were recorded within one week, including the number of patients receiving nutrition, the number of days nutrition was provided, the caloric intake and protein intake, feeding intolerance and prokinetic drug administration. Other collected data included the sequential organ failure assessment score (SOFA score), the Acute Physiology and Chronic Health Evaluation (APACHE) II score, the use of mechanical ventilation (the number of patients and the duration), use of vasoactive drugs and the number of renal replacement treatments (RRT) received by each patient during their ICU stay. The primary outcome was 28-day mortality. Additionally, we analysed the correlation between plasma Ach levels and inflammation, as well as the correlation between plasma Ach and CCK levels. Moreover, a multivariate regression analysis was performed to examine the independent effects of different variables on 28-day mortality and Ach levels.

RESULTS

The overall 28-day mortality was 28.3% (32/113). Eighty-two patients tolerated enteral nutrition. Compared with Day 0 15.6 (2.8) nmol/l, the plasma Ach level was significantly increased on Day 3 18.6 (6.7) nmol/l, Day 5 19.3 (6.2) nmol/l and Day 7 19.7 (4.3) nmol/l (p < .001). Compared with Day 0176.2 (50.4) pg/ml, the plasma TNF-α level was significantly decreased on Day 3144.0 (77.4) pg/ml, Day 5127.3 (51.8) pg/ml and Day 7111.4 (42.5) pg/ml (p < .05). Compared with Day 0, the plasma IL1-β level was significantly decreased on Day 7 (p < .05). The plasma IL6 level was significantly decreased on Day 5 and Day 7 (p < .05) compared with Day 0. Compared with Day 0, the plasma CCK level was significantly increased on Day 3, 5 and 7 (p < .001). The correlation analysis revealed negative correlations between Ach levels and inflammation (p < .001), and a positive correlation between CCK and Ach levels (r = 0.775, p < .001). A comparison of patients who did or did not tolerate EEN revealed significant differences in the plasma levels of Ach, TNF-α, IL6 and CCK (p < .05). Significant differences in plasma levels of Ach, TNF-α, IL1-β, IL6 and CCK were observed between 28-day survivors and non-survivors (p < .05). The multivariate logistic regression analysis identified vasopressor support, RRT, the administration of EEN, SOFA score, APACHE II score at ICU admission and plasma Ach levels as independent determinants of 28-day mortality. Additionally, the multivariate linear regression analysis identified EEN, plasma lactate, mechanical ventilation, the SOFA score and plasma CCK levels as independent determinants of plasma Ach levels.

CONCLUSIONS

The administration of EEN to critically ill patients contributed to the increased plasma Ach levels and decreased inflammatory markers. The effect of EEN on Ach levels is partially attributed to the increase in CCK levels. Elevated plasma Ach levels indicate a better prognosis. Clinical trials identifier: NCT03612206.

Amelioration of PM2.5-induced lung toxicity in rats by nutritional supplementation with fish oil and Vitamin E

BACKGROUND

Exposure to fine particulate matter (PM_2.5) has been associated with respiratory morbidity and mortality. Identification of interventional measures that are efficacious against PM_2.5-induced toxicity may provide public health benefits. This study examined the inhibitory effects of nutritional supplementation with fish oil as a source of omega-3 fatty acids and vitamin E (Vit E) on PM_2.5-induced lung toxicity in rats.

METHOD

Sixty four male Sprague Dawley rats were gavaged with phosphate buffered saline (PBS), corn oil (5 ml/kg), fish oil (150 mg/kg), or Vit E (75 mg/kg), respectively, once a day for 21 consecutive days prior to intratracheal instillation of PM_2.5 (10 mg/kg) every other day for a total of 3 times. Serum and bronchoalveolar lavage fluids (BALFs) were collected 24 h after the last instillation of PM_2.5. Levels of total proteins (TP), lactate dehydrogenase (LDH), superoxide dismutase (SOD), 8-epi-prostaglandin F2α (8-epi-PGF2α), interleukin-1β (IL-1β), C-reactive protein (CRP), IL-6, and tumor necrosis factor-ɑ (TNF-ɑ) were analyzed for markers of cell injury and inflammation. Additionally, histological alterations of lung tissues were examined by hematoxylin-eosin staining.

RESULT

Exposure to PM_2.5 resulted in lung toxicity, represented as increased levels of total proteins, LDH, 8-epi-PGF2α, IL-1β and TNF-α, and increased infiltration of inflammatory cells, and decreased SOD in the BALFs, and systemic inflammation, as evinced by increased levels of CRP and IL-6 in serum. Strikingly, supplementation with fish oil but not Vit E significantly ameliorated PM_2.5-induced lung toxicity and systemic inflammation.

CONCLUSION

PM_2.5 exposure induces oxidative stress, lung injury and inflammation, which is ameliorated significantly by fish oil and partially by Vit E.

An update on diet and nutritional factors in systemic lupus erythematosus management

Systemic lupus erythematosus (SLE) is a chronic inflammatory and autoimmune disease characterised by multiple organ involvement and a large number of complications. SLE management remains complicated owing to the biological heterogeneity between patients and the lack of safe and specific targeted therapies. There is evidence that dietary factors can contribute to the geoepidemiology of autoimmune diseases such as SLE. Thus, diet therapy could be a promising approach in SLE owing to both its potential prophylactic effects, without the side effects of classical pharmacology, and its contribution to reducing co-morbidities and improving quality of life in patients with SLE. However, the question arises as to whether nutrients could ameliorate or exacerbate SLE and how they could modulate inflammation and immune function at a molecular level. The present review summarises preclinical and clinical experiences to provide the reader with an update of the positive and negative aspects of macro- and micronutrients and other nutritional factors, including dietary phenols, on SLE, focusing on the mechanisms of action involved.

The Effect of Immunonutrition on the Postoperative Complications in Thymoma with Myasthenia Gravis

Object. To test whether preoperative immunonutrition is efficacious in reducing postoperative complications in patients of thymoma with myasthenia gravis (MG). Material and Methods. A total of 244 patients operated on for thymoma with myasthenia gravis were prospectively assigned to two groups, each receiving seven-day preoperative and seven-day postoperative nutrition. The patients in immunonutrition group were given oral immunonutrition (IN). The patients in control group received oral standard nutrition. Immunonutritional and inflammatory biomarkers (IgA, IgG, IgM, CD3t, CD4t, CD8t, CD4t/CD8t ratio, NK-cell, prealbumin, albumin, white blood cells counts, and C-reactive protein) and clinical variables (age, gender, BMI, performance status, type of thymoma, type of MG, operative time, pathology, operative approach, postoperative complications, quantity of drainage, hospital stays) were examined. Results. A significant reduction in the length of hospital stay, quantity of drainage, and postoperative complications was observed in the IN group (p < 0.05). An increase in the level of IgA, IgG, IgM, CD3+T, CD4+T, CD4+T/CD8+T, WBC, CRP, and NK-cell in the IN group was observed after thymectomy, while a decrease was seen with regard to prealbumin and albumin (p < 0.05). Conclusion. Preoperative immunonutrition support is effective in reducing postoperative complications in patients of thymoma with MG. It helps to lower the risk of postoperative infectious complications and hospital stays.

Silica-Triggered Autoimmunity in Lupus-Prone Mice Blocked by Docosahexaenoic Acid Consumption

Occupational exposure to respirable crystalline silica (cSiO2, quartz) is etiologically linked to systemic lupus erythematosus (lupus) and other human autoimmune diseases (ADs). In the female NZBWF1 mouse, a widely used animal model that is genetically prone to lupus, short-term repeated intranasal exposure to cSiO2 triggers premature initiation of autoimmune responses in the lungs and kidneys. In contrast to cSiO2's triggering action, consumption of the ω-3 polyunsaturated fatty acid docosahexaenoic acid (DHA) prevents spontaneous onset of autoimmunity in this mouse strain. The aim of this study was to test the hypothesis that consumption of DHA will prevent cSiO2-triggered autoimmunity in the female NZBWF1 mouse. Mice (6 wk old) were fed isocaloric AIN-93G diets containing 0.0, 0.4, 1.2 or 2.4% DHA. Two wk after initiating feeding, mice were intranasally instilled with 1 mg cSiO2 once per wk for 4 wk and maintained on experimental diets for an additional 12 wk. Mice were then sacrificed and the lung, blood and kidney assessed for markers of inflammation and autoimmunity. DHA was incorporated into lung, red blood cells and kidney from diet in a concentration-dependent fashion. Dietary DHA dose-dependently suppressed cSiO2-triggered perivascular leukocyte infiltration and ectopic lymphoid tissue neogenesis in the lung. DHA consumption concurrently inhibited cSiO2-driven elevation of proinflammatory cytokines, B-cell proliferation factors, IgG and anti-dsDNA Ig in both bronchoalveolar lavage fluid and plasma. DHA's prophylactic effects were further mirrored in reduced proteinuria and glomerulonephritis in cSiO2-treated mice. Taken together, these results reveal that DHA consumption suppresses cSiO2 triggering of autoimmunity in female NZBWF1 mice as manifested in the lung, blood and kidney. Our findings provide novel insight into how dietary modulation of the lipidome might be used to prevent or delay triggering of AD by cSiO2. Such knowledge opens the possibility of developing practical, low-cost preventative strategies to reduce the risk of initiating AD and subsequent flaring in cSiO2-exposed individuals. Additional research in this model is required to establish the mechanisms by which DHA suppresses cSiO2-induced autoimmunity and to ascertain unique lipidome signatures predictive of susceptibility to cSiO2-triggered AD.

Effectiveness of ω-3 Polyunsaturated Fatty Acids Based Lipid Emulsions for Treatment of Patients after Hepatectomy: A Prospective Clinical Trial

Objective: The present study aimed to investigate the effectiveness of parenteral nutritional support with ω-3 PUFAs–based lipid emulsions in patients after liver resection. Methods: A total of 119 patients were randomly assigned to the immunonutrition (IM) group (n = 59) and control group (n = 60). The IM group was continuously given Omegaven^® 10% 100 mL/day rather than regular nutrition for five days postoperatively. Venous blood samples were obtained from all subjects before surgery and D1, D3 and D7 after surgery. Results: No significant difference was found in baseline characteristics of the two groups. On D1 after surgery, no statistically significant differences were observed in the blood sample tests between the two groups. On D3 after surgery, the levels of white blood cell count (WBC), alanine aminotransferase (ALT), aspartate transaminase (AST) and total bilirubin (TBil) were dramatically decreased in the IM group (t = 3.065, p = 0.003; t = 2.149, p = 0.034; t = 5.313, p= 0.001; and t = 2.419, p = 0.017, respectively). Furthermore, on D7 after surgery, not only could a significant decrease be observed in the IM group concerning the levels of WBC, ALT and TBil (t = 3.025, p = 0.003; t = 2.094, p = 0.038; and t = 2.046, p = 0.043, respectively), but it was also seen in the level of Δprothrombintime (PT) (t = 2.450, p = 0.016). An increase in the level of prealbumin (Pre-Alb) in the IM group was observed on D7 after surgery (t = 2.237, p = 0.027). The frequency of total complications in the IM group were significantly lower than in the control group (χ² = 4.225, p = 0.040 and χ² = 3.174, p = 0.075). The trend favored the IM group in reducing the total infective complications rate (χ² = 3.174, p = 0.075). A significant decrease in the duration of the hospital stay after surgery was also observed in the IM group (t = 2.012, p = 0.047).Conclusion: ω-3 PUFAs–based lipid emulsions for treatment of patients after hepatectomy are safe and effective in controlling inflammation, protecting liver function, and consequently reducing the rate of total complications and the duration of the hospital stay.

Omega-3 Fatty Acids in Modern Parenteral Nutrition: A Review of the Current Evidence

Intravenous lipid emulsions are an essential component of parenteral nutrition regimens. Originally employed as an efficient non-glucose energy source to reduce the adverse effects of high glucose intake and provide essential fatty acids, lipid emulsions have assumed a larger therapeutic role due to research demonstrating the effects of omega-3 and omega-6 polyunsaturated fatty acids (PUFA) on key metabolic functions, including inflammatory and immune response, coagulation, and cell signaling. Indeed, emerging evidence suggests that the effects of omega-3 PUFA on inflammation and immune response result in meaningful therapeutic benefits in surgical, cancer, and critically ill patients as well as patients requiring long-term parenteral nutrition. The present review provides an overview of the mechanisms of action through which omega-3 and omega-6 PUFA modulate the immune-inflammatory response and summarizes the current body of evidence regarding the clinical and pharmacoeconomic benefits of intravenous n-3 fatty acid-containing lipid emulsions in patients requiring parenteral nutrition.

Docosahexaenoic Acid Attenuated Experimental Chronic Colitis in Interleukin 10-Deficient Mice by Enhancing Autophagy Through Inhibition of the mTOR Pathway

BACKGROUND

In the battle against Crohn's disease, autophagy stimulation is a promising therapeutic option-one both new and newly rediscovered. In experimental models, docosahexaenoic acid (DHA)-a long-chain polyunsaturated fatty acid-has been demonstrated to be useful in the treatment of inflammatory bowel disease through inhibition of the nuclear factor-κB pathway. However, the impact of DHA on autophagy in the colon remains unclear.

METHODS

Mice were divided into 3 groups: wild type (placebo), the interleukin 10 knockout group (IL-10^-/-, placebo), and the DHA group (IL-10^-/-, DHA). DHA was administered to IL-10^-/- mice by gavage at a dosage of 35.5 mg/kg/d for 2 weeks. The severity of colitis, expression of proinflammatory cytokines, expression/distribution of LC3B, and mTOR signaling pathway were evaluated in the proximal colon tissues collected from all mice at the end of the experiment.

RESULTS

DHA administration ameliorated experimental colitis in the IL-10^-/- mice, as demonstrated by decreased proinflammatory cytokines (TNF-α and IFN-γ), reduced infiltration of inflammatory cells, and lowered histologic scores of the proximal colon mucosa. Moreover, in the DHA-treated mice, enhanced autophagy was observed to be associated with (1) increased expression and restoration of the distribution integrity of LC3B in the colon and (2) inhibition of the mTOR signaling pathway.

CONCLUSION

This study showed that DHA therapy could attenuate experimental chronic colitis in IL-10^-/- mice by triggering autophagy via inhibition of the mTOR pathway.

Comparative effects of n-3, n-6 and n-9 unsaturated fatty acid-rich diet consumption on lupus nephritis, autoantibody production and CD4+ T cell-related gene responses in the autoimmune NZBWF1 mouse

Mortality from systemic lupus erythematosus (SLE), a prototypical autoimmune disease, correlates with the onset and severity of kidney glomerulonephritis. There are both preclinical and clinical evidence that SLE patients may benefit from consumption of n-3 polyunsaturated fatty acids (PUFA) found in fish oil, but the mechanisms remain unclear. Here we employed the NZBWF1 SLE mouse model to compare the effects of dietary lipids on the onset and severity of autoimmune glomerulonephritis after consuming: 1) n-3 PUFA-rich diet containing docosahexaenoic acid-enriched fish oil (DFO), 2) n-6 PUFA-rich Western-type diet containing corn oil (CRN) or 3) n-9 monounsaturated fatty acid (MUFA)-rich Mediterranean-type diet containing high oleic safflower oil (HOS). Elevated plasma autoantibodies, proteinuria and glomerulonephritis were evident in mice fed either the n-6 PUFA or n-9 MUFA diets, however, all three endpoints were markedly attenuated in mice that consumed the n-3 PUFA diet until 34 wk of age. A focused PCR array was used to relate these findings to the expression of 84 genes associated with CD4+ T cell function in the spleen and kidney both prior to and after the onset of the autoimmune nephritis. n-3 PUFA suppression of autoimmunity in NZBWF1 mice was found to co-occur with a generalized downregulation of CD4+ T cell-related genes in kidney and/or spleen at wk 34. These genes were associated with the inflammatory response, antigen presentation, T cell activation, B cell activation/differentiation and leukocyte recruitment. Quantitative RT-PCR of representative affected genes confirmed that n-3 PUFA consumption was associated with reduced expression of CD80, CTLA-4, IL-10, IL-18, CCL-5, CXCR3, IL-6, TNF-α and osteopontin mRNAs in kidney and/or spleens as compared to mice fed n-6 PUFA or n-9 MUFA diets. Remarkably, many of the genes identified in this study are currently under consideration as biomarkers and/or biotherapeutic targets for SLE and other autoimmune diseases.

Nutrition, diet and immunosenescence

Ageing is characterized by immunosenescence and the progressive decline in immunity in association with an increased frequency of infections and chronic disease. This complex process affects both the innate and adaptive immune systems with a progressive decline in most immune cell populations and defects in activation resulting in loss of function. Although host genetics and environmental factors, such as stress, exercise and diet can impact on the onset or course of immunosenescence, the mechanisms involved are largely unknown. This review focusses on identifying the most significant aspects of immunosenescence and on the evidence that nutritional intervention might delay this process, and consequently improve the quality of life of the elderly.

Rapid incorporation of ω-3 fatty acids into colonic tissue after oral supplementation in patients with colorectal cancer: a randomized, placebo-controlled intervention trial

BACKGROUND

The purpose of the study was to examine whether a preoperative supplement with ω-3 fatty acids (FAs) leads to their incorporation into colonic tissue in patients scheduled for colorectal cancer surgery. This would be of interest because ω-3 FAs have potential beneficial (local) immunological effects that might benefit these patients.

METHODS

In a randomized, double-blind, prospective, placebo-controlled, single-center intervention trial, patients referred for elective colorectal cancer surgery received either an ω-3 FA-enriched oral nutrition supplement (ONS) (200 mL twice daily) providing 2.0 g of eicosapentaenoic acid (EPA) and 1.0 g of docosahexaenoic acid (DHA) per day or a standard ONS for 7 days before surgery. Tissue samples from healthy colonic tissue (mucosa and muscular layer) were obtained during surgery, and tissue fatty acid composition was analyzed by gas chromatography.

RESULTS

EPA was significantly higher in colonic mucosa (P = .001) and in the colonic muscular layer (P = .004) in the ω-3 FA group compared with controls. Patients in the ω-3 FA group also tended to have higher docosapentaenoic acid and DHA levels in colonic tissue.

CONCLUSIONS

EPA is incorporated rapidly into colonic mucosa and colonic muscular layer in patients given 3 g of ω-3 FA daily for 7 days before surgery for colorectal cancer. This may lead to potential beneficially effects on (local) immune function, which might benefit these patients.

n-3 Fatty acids, inflammation and immunity: new mechanisms to explain old actions

Numerous effects of n-3 fatty acids EPA and DHA on functional responses of cells involved in inflammation and immunity have been described. Fatty acid-induced modifications in membrane order and in the availability of substrates for eicosanoid synthesis are long-standing mechanisms that are considered important in explaining the effects observed. More recently, effects on signal transduction pathways and on gene expression profiles have been identified. Over the last 10 years or so, significant advances in understanding the mechanisms of action of n-3 fatty acids have been made. These include the identification of new actions of lipid mediators that were already described and of novel interactions among those mediators and the description of an entirely new family of lipid mediators, resolvins and protectins that have anti-inflammatory actions and are critical to the resolution of inflammation. It is also recognised that EPA and DHA can inhibit activation of the prototypical inflammatory transcription factor NF-κB. Recent studies suggest three alternative mechanisms by which n-3 fatty acids might have this effect. Within T-cells, as well as other cells of relevance to immune and inflammatory responses, EPA and DHA act to disrupt very early events involving formation of the structures termed lipid rafts which bring together various proteins to form an effective signalling platform. In summary, recent research has identified a number of new mechanisms of action that help to explain previously identified effects of n-3 fatty acids on inflammation and immunity.

Lipids for intravenous nutrition in hospitalised adult patients: a multiple choice of options

Lipids used in parenteral nutrition provide energy, building blocks and essential fatty acids. Traditionally, these lipids have been based on n-6 PUFA-rich vegetable oils particularly soyabean oil. This may not be optimal because soyabean oil may present an excessive supply of linoleic acid. Alternatives to use of soyabean oil include its partial replacement by medium-chain TAG, olive oil or fish oil, either alone or in combination. Lipid emulsions containing these alternatives are well tolerated without adverse effects in a wide range of hospitalised adult patients. Lipid emulsions that include fish oil have been used in parenteral nutrition in adult patients' post-surgery (mainly gastrointestinal). This has been associated with alterations in patterns of inflammatory mediators and in immune function and, in some studies, a reduction in length of intensive care unit and hospital stay. These benefits are emphasised through recent meta-analyses. Perioperative administration of fish oil may be superior to post-operative administration. Parenteral fish oil has been used in critically ill adults. Here, the influence on inflammatory processes, immune function and clinical endpoints is not clear, since there are too few studies and those that are available report contradictory findings. However, some studies found reduced inflammation, improved gas exchange and shorter length of hospital stay in critically ill patients if they receive fish oil. More and better trials are needed in patient groups in which parenteral nutrition is used and where fish oil may offer benefits.

Changes in plasma and erythrocyte omega-6 and omega-3 fatty acids in response to intravenous supply of omega-3 fatty acids in patients with hepatic colorectal metastases

Background

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are functionally the most important omega-3 polyunsaturated fatty acids (PUFAs). Oral supply of these fatty acids increases their levels in plasma and cell membranes, often at the expense of the omega-6 PUFAs arachidonic acid (ARA) and linoleic acid. This results in an altered pattern of lipid mediator production to one which is less pro-inflammatory. We investigated whether short term intravenous supply of omega-3 PUFAs could change the levels of EPA, DHA, ARA and linoleic acid in plasma and erythrocytes in patients with hepatic colorectal metastases.

Methods

Twenty patients were randomised to receive a 72 hour infusion of total parenteral nutrition with (treatment group) or without (control group) omega-3 PUFAs. EPA, DHA, ARA and linoleic acid were measured in plasma phosphatidylcholine (PC) and erythrocytes at several times points up to the end of infusion and 5 to 12 days (mean 9 days) after stopping the infusion.

Results

The treatment group showed increases in plasma PC EPA and DHA and erythrocyte EPA and decreases in plasma PC and erythrocyte linoleic acid, with effects most evident late in the infusion period. Plasma PC and erythrocyte EPA and linoleic acid all returned to baseline levels after the 5–12 day washout. Plasma PC DHA remained elevated above baseline after washout.

Conclusions

Intravenous supply of omega-3 PUFAs results in a rapid increase of EPA and DHA in plasma PC and of EPA in erythrocytes. These findings suggest that infusion of omega-3 PUFAs could be used to induce a rapid effect especially in targeting inflammation.

Trial registration

http://www.clinicaltrials.gov identifier NCT00942292

Pharmaconutrition: acute fatty acid modulation of circulating cytokines in elderly patients in the ICU

BACKGROUND

Enteral supply of ω-3 polyunsaturated fatty acids has been used in an attempt to modulate inflammation and improve outcome in critically ill patients. However, enteral administration may be slow to change membrane composition and therefore may not be the best route to supply these fatty acids in patients with acute conditions. This study evaluated the effects of short-term intravenous (IV) administration of fish oil-based lipid emulsion (FLE) as pharmaconutrition on cytokine levels in critically ill elderly patients.

METHODS

Enterally fed patients (n = 40; aged 60-80 years) were recruited in the first 48 hours of intensive care unit (ICU) admission. Fifteen patients received IV FLE (0.2 g/kg body weight) over 6 hours for 3 consecutive days, and 25 patients did not receive IV lipid (control). Samples were collected before and 24 hours and 72 hours after the third FLE infusion. Nutrient intakes, clinical parameters, and serum cytokine concentrations were measured.

RESULTS

Compared with the control, FLE resulted in higher energy intake, lower serum tumor necrosis factor-α and interleukin (IL)-8 concentrations, and higher serum IL-10. These differences occurred around 7-9 days of ICU stay at the time of the patient's extubation. ICU stay, mortality, and markers of coagulation and liver function did not differ between groups.

CONCLUSIONS

Short-term IV FLE modulates some inflammatory markers in critically ill elderly patients receiving enteral nutrition (EN), suggesting an anti-inflammatory effect. This may be a benefit and suggests a role for FLE administration as a supplement in elderly ICU patients receiving standard EN.

Omega-3 polyunsaturated fatty acids and inflammatory processes: nutrition or pharmacology?

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are n-3 fatty acids found in oily fish and fish oil supplements. These fatty acids are able to inhibit partly a number of aspects of inflammation including leucocyte chemotaxis, adhesion molecule expression and leucocyte-endothelial adhesive interactions, production of eicosanoids like prostaglandins and leukotrienes from the n-6 fatty acid arachidonic acid, production of inflammatory cytokines and T cell reactivity. In parallel, EPA gives rise to eicosanoids that often have lower biological potency than those produced from arachidonioc acid and EPA and DHA give rise to anti-inflammatory and inflammation resolving resolvins and protectins. Mechanisms underlying the anti-inflammatory actions of n-3 fatty acids include altered cell membrane phospholipid fatty acid composition, disruption of lipid rafts, inhibition of activation of the pro-inflammatory transcription factor nuclear factor kappa B so reducing expression of inflammatory genes, activation of the anti-inflammatory transcription factor NR1C3 (i.e. peroxisome proliferator activated receptor γ) and binding to the G protein coupled receptor GPR120. These mechanisms are interlinked. In adult humans, an EPA plus DHA intake greater than 2 g day⁻¹ seems to be required to elicit anti-inflammatory actions, but few dose finding studies have been performed. Animal models demonstrate benefit from n-3 fatty acids in rheumatoid arthritis (RA), inflammatory bowel disease (IBD) and asthma. Clinical trials of fish oil in patients with RA demonstrate benefit supported by meta-analyses of the data. Clinical trails of fish oil in patients with IBD and asthma are inconsistent with no overall clear evidence of efficacy.

Docosahexaenoic and arachidonic acid levels in extremely low birth weight infants with prolonged exposure to intravenous lipids

OBJECTIVE

To report changes in red blood cell long-chain polyunsaturated fatty acids levels in extremely low birth weight (ELBW) infants relative to duration of intravenous lipid emulsion.

STUDY DESIGN

Serial blood samples were collected from 26 ELBW infants during the first 2 months of life in the neonatal intensive care unit using a prospective cohort study design. The primary outcome was the change in long-chain polyunsaturated fatty acids levels over the study period relative to a duration of intravenous lipid emulsion of either ≤ 28 days or >28 days. Secondary outcomes included parenteral and enteral nutritional exposures as well as prematurity-associated morbidities. Longitudinal regression estimated changes in fatty acid levels between the 2 exposure groups.

RESULTS

Infants with >28 days intravenous lipid emulsion had 36 more days of intravenous lipid emulsion than did those with ≤ 28 days (P < .001). Docosahexaenoic acid significantly decreased over time in all infants and decreased significantly more in infants exposed to intravenous lipid emulsion for >28 days (P = .03). Arachidonic acid significantly decreased over the study period but the decrease was not related to intravenous lipid emulsion duration. Linoleic and α-linolenic acids had significantly larger increases over time in those with longer exposure to intravenous lipid emulsion (P < .01).

CONCLUSION

Docosahexaenoic acid status of ELBW infants declined significantly in the first 2 months of life and the decline was significantly greater in those exposed to intravenous lipid emulsion >28 days compared with those exposed ≤ 28 days.

Supplemental intravenous n-3 fatty acids and n-3 fatty acid status and outcome in critically ill elderly patients in the ICU receiving enteral nutrition

BACKGROUND & AIMS

N-3 fatty acids (FA) may have benefits in ICU patients. The aims were to identify whether FA status is altered in critical illness and to evaluate the effect of supplemental intravenous n-3 FA on plasma FA status and clinical outcome in ICU patients receiving enteral nutrition.

METHODS

Enterally fed patients (n = 49; 60-80 years) were recruited in the first 48 h of ICU admission. Fifteen patients received n-3 FA emulsion (0.2 g/kg) over 6 h for 3 consecutive days, and 34 patients did not (control). Samples were collected before supplementation, and 24 and 72 h after the third infusion. Nineteen healthy elderly subjects were also studied; they gave a single blood sample. FA were measured in plasma phosphatidylcholine (PC).

RESULTS

Critically ill patients had altered plasma PC FA compared with healthy elderly subjects. Surviving ICU patients had higher levels of docosahexaenoic acid and total n-3 FA and a lower ratio of n-6:n-3 FA in plasma PC than non-survivors. Infusion of n-3 FA increased eicosapentaenoic, docosahexaenoic and total n-3 FA, and decreased arachidonic and total n-6 FA and n-6:n-3 FA and arachidonic:eicosapentaenoic acid ratios. Gas exchange was enhanced 72 h after the third n-3 FA infusion (p = 0.001).

CONCLUSIONS

Critically ill patients may have altered plasma FA profiles. A higher total n-3 FA and docosahexaenoic acid content in plasma PC is associated with survival and improved gas exchange.

Parenteral omega-3 fatty acids: pouring oil on troubled waters?

A meta-analysis of parenteral fish oil in 23 studies in intensive care unit (ICU) and non-ICU patients reported a reduced infection rate (significant in ICU patients) and shorter lengths of ICU and hospital stays (both non-ICU and ICU patients). Parenteral fish oil reduced inflammation and improved oxygenation index and liver function. The findings of the meta-analysis are discussed in this report.

Effects of a diabetes-specific enteral nutrition on nutritional and immune status of diabetic, obese, and endotoxemic rats: interest of a graded arginine supply

OBJECTIVE

Obese and type 2 diabetic patients present metabolic disturbance-related alterations in nonspecific immunity, to which the decrease in their plasma arginine contributes. Although diabetes-specific formulas have been developed, they have never been tested in the context of an acute infectious situation as can be seen in intensive care unit patients. Our aim was to investigate the effects of a diabetes-specific diet enriched or not with arginine in a model of infectious stress in a diabetes and obesity situation. As a large intake of arginine may be deleterious, this amino acid was given in graded fashion.

DESIGN

Randomized, controlled experimental study.

SETTING

University research laboratory.

SUBJECTS

Zucker diabetic fatty rats.

INTERVENTIONS

Gastrostomized Zucker diabetic fatty rats were submitted to intraperitoneal lipopolysaccharide administration and fed for 7 days with either a diabetes-specific enteral nutrition without (G group, n=7) or with graded arginine supply (1-5 g/kg/day) (GA group, n=7) or a standard enteral nutrition (HP group, n=10).

MEASUREMENTS AND MAIN RESULTS

Survival rate was better in G and GA groups than in the HP group. On day 7, plasma insulin to glucose ratio tended to be lower in the same G and GA groups. Macrophage tumor necrosis factor-α (G: 5.0±1.1 ng/2×10⁶ cells·hr⁻¹; GA: 3.7±0.8 ng/2×10⁶ cells·hr⁻¹; and HP: 1.7±0.6 ng/2×10⁶ cells·hr⁻¹; p<.05 G vs. HP) and nitric oxide (G: 4.5±1.1 ng/2×10⁶ cells·hr⁻¹; GA: 5.1±1.0 ng/2×10⁶ cells·hr⁻¹; and HP: 1.0±0.5 nmol/2×10⁶ cells·hr⁻¹; p<.05 G and GA vs. HP) productions were higher in the G and GA groups compared to the HP group. Macrophages from the G and GA groups exhibited increased arginine consumption.

CONCLUSIONS

In diabetic obese and endotoxemic rats, a diabetes-specific formula leads to a lower mortality, a decreased insulin resistance, and an improvement in peritoneal macrophage function. Arginine supplementation has no additional effect. These data support the use of such disease-specific diets in critically ill diabetic and obese patients.

Fish to meat intake ratio and cooking oils are associated with hepatitis C virus carriers with persistently normal alanine aminotransferase levels

AIM

  Dietary habits are involved in the development of chronic inflammation; however, the impact of dietary profiles of hepatitis C virus carriers with persistently normal alanine transaminase levels (HCV-PNALT) remains unclear. The decision-tree algorithm is a data-mining statistical technique, which uncovers meaningful profiles of factors from a data collection. We aimed to investigate dietary profiles associated with HCV-PNALT using a decision-tree algorithm.

METHODS

  Twenty-seven HCV-PNALT and 41 patients with chronic hepatitis C were enrolled in this study. Dietary habit was assessed using a validated semiquantitative food frequency questionnaire. A decision-tree algorithm was created by dietary variables, and was evaluated by area under the receiver operating characteristic curve analysis (AUROC).

RESULTS

  In multivariate analysis, fish to meat ratio, dairy product and cooking oils were identified as independent variables associated with HCV-PNALT. The decision-tree algorithm was created with two variables: a fish to meat ratio and cooking oils/ideal bodyweight. When subjects showed a fish to meat ratio of 1.24 or more, 68.8% of the subjects were HCV-PNALT. On the other hand, 11.5% of the subjects were HCV-PNALT when subjects showed a fish to meat ratio of less than 1.24 and cooking oil/ideal bodyweight of less than 0.23 g/kg. The difference in the proportion of HCV-PNALT between these groups are significant (odds ratio 16.87, 95% CI 3.40-83.67, P = 0.0005). Fivefold cross-validation of the decision-tree algorithm showed an AUROC of 0.6947 (95% CI 0.5656-0.8238, P = 0.0067).

CONCLUSION

  The decision-tree algorithm disclosed that fish to meat ratio and cooking oil/ideal bodyweight were associated with HCV-PNALT.

Parenteral lipid administration to very-low-birth-weight infants--early introduction of lipids and use of new lipid emulsions: a systematic review and meta-analysis

BACKGROUND

The use of intravenous lipid emulsions in preterm infants has been limited by concerns regarding impaired lipid tolerance. As a result, the time of initiation of parenteral lipid infusion to very-low-birth-weight (VLBW) infants varies widely among different neonatal intensive care units. However, lipids provide energy for protein synthesis and supply essential fatty acids that are necessary for central nervous system development.

OBJECTIVE

The objective was to summarize the effects of initiation of lipids within the first 2 d of life and the effects of different lipid compositions on growth and morbidities in VLBW infants.

DESIGN

A systematic review and meta-analysis of publications identified in a search of PubMed, EMBASE, and Cochrane databases was undertaken. Randomized controlled studies were eligible if information on growth was available.

RESULTS

The search yielded 14 studies. No differences were observed in growth or morbidity with early lipid initiation. We found a weak favorable association of non-purely soybean-based emulsions with the incidence of sepsis (RR: 0.75; 95% CI: 0.56, 1.00).

CONCLUSIONS

The initiation of lipids within the first 2 d of life in VLBW infants appears to be safe and well tolerated; however, beneficial effects on growth could not be shown for this treatment nor for the type of lipid emulsion. Emulsions that are not purely soybean oil-based might be associated with a lower incidence of sepsis. Large-scale randomized controlled trials in preterm infants are warranted to determine whether early initiation of lipids and lipid emulsions that are not purely soybean oil-based results in improved long-term outcomes.

Droplet-size distribution and stability of commercial injectable lipid emulsions containing fish oil

PURPOSE

The droplet size of commercial fish oil-containing injectable lipid emulsions, including conformance to United States Pharmacopeia (USP) standards on fat-globule size, was investigated.

METHODS

A total of 18 batches of three multichamber parenteral products containing the emulsion SMOFlipid as a component were analyzed. Samples from multiple lots of the products were evaluated to determine compliance with standards on the volume-weighted percentage of fat exceeding 0.05% (PFAT(5)) specified in USP chapter 729 to ensure the physical stability of i.v. lipid emulsions. The products were also analyzed to determine the effects of various storage times (3, 6, 9, and 12 months) and storage temperatures (25, 30, and 40 °C) on product stability. Larger-size lipid particles were quantified via single-particle optical sensing (SPOS). The emulsion's droplet-size distribution was determined via laser light scattering.

RESULTS

SPOS and light-scattering analysis demonstrated mean PFAT(5) values well below USP-specified globule-size limits for all the tested products under all study conditions. In addition, emulsion aging at any storage temperature in the range studied did not result in a significant increase of PFAT(5) values, and mean droplet-size values did not change significantly during storage of up to 12 months at temperatures of 25-40 °C.

CONCLUSION

PFAT(5) values were below the USP upper limits in SMOFlipid samples from multiple lots of three multichamber products after up to 12 months of storage at 25 or 30 °C or 6 months of storage at 40 °C.

Nutrition and sarcopenia: evidence for an interaction

Nutritional interventions that might influence sarcopenia, as indicated by literature reporting on sarcopenia per se as well as dynapenia and frailty, are reviewed in relation to potential physiological aetiological factors, i.e. inactivity, anabolic resistance, inflammation, acidosis and vitamin D deficiency. As sarcopenia occurs in physically active and presumably well-nourished populations, it is argued that a simple nutritional aetiology is unlikely and unequivocal evidence for any nutritional influence is extremely limited. Dietary protein is probably the most widely researched nutrient but only for frailty is there one study showing evidence of an aetiological influence and most intervention studies with protein or amino acids have proved ineffective with only a very few exceptions. Fish oil has been shown to attenuate anabolic resistance of muscle protein synthesis in one study. There is limited evidence for a protective influence of antioxidants and inducers of phase 2 proteins on sarcopenia, dynapenia and anabolic resistance in human and animal studies. Also fruit and vegetables may protect against acidosis-induced sarcopenia through their provision of dietary potassium. While severe vitamin D deficiency is associated with dynapenia and sarcopenia, the evidence for a beneficial influence of increasing vitamin D status above the severe deficiency level is limited and controversial, especially in men. On this basis there is insufficient evidence for any more specific nutritional advice than that contained in the general healthy lifestyle–healthy diet message: i.e. avoiding inactivity and low intakes of food energy and nutrients and maintain an active lifestyle with a diet providing a rich supply of fruit and vegetables and frequent oily fish.

Short-term infusion of a fish oil-based lipid emulsion modulates fatty acid status, but not immune function or (anti)oxidant balance: a randomized cross-over study

BACKGROUND AND AIMS

Studies suggest clinical benefits of parenteral fish oil (FO), rich in n-3 polyunsaturated fatty acids (PUFAs), over soyabean oil (SO), rich in n-6 PUFAs, in patients with pro-inflammatory conditions such as sepsis and trauma. Because the mechanisms behind these observations remain unclear, the present study explored the effects of intravenous infusion of FO and SO on fatty acid incorporation, immune functions and (anti)oxidant balance in healthy human volunteers.

METHODS

Saline, a SO emulsion and a FO emulsion were administered for one hour on three consecutive days at a rate of 0·2 g/kg BW/h to eight subjects in a randomized cross-over design with a 3-week interval between treatments. Plasma phospholipid and peripheral blood mononuclear cell (PBMC) fatty acid compositions, and leucocyte counts and functions were assessed prior to the first infusion (T = 0, baseline) and 1 day (T = 4, early effects) and 8 days (T = 11, late effects) after the third infusion.

RESULTS

Fish oil infusion significantly increased n-3 PUFA proportions and decreased n-6 PUFA proportions in plasma phospholipids and PBMCs. There were no differences in immune functions or (anti)oxidant balance between treatments at any time.

CONCLUSIONS

The present lipid infusion protocol appears to be safe and well tolerated and provides significant incorporation of n-3 PUFAs into plasma phospholipids and PBMCs. In the absence of overt inflammation, no direct effects of FO were observed on immune function or (anti)oxidant balance. This model may be useful to evaluate effects of parenteral lipids in other settings, for example in individuals displaying an inflammatory state.

Nutrition delivery for obese ICU patients: delivery issues, lack of guidelines, and missed opportunities

The most appropriate enteral formula for the severely obese population has yet to be determined. The obese patient in the intensive care unit (ICU) creates numerous difficulties for managing care, one being the ability to deliver appropriate and timely nutrition. Access for nutrition therapy, either enteral or parenteral, can also create a challenge. Currently, no specific guidelines are available on a national or international scale to address the issues of how and when to feed the obese patient in the ICU. A bias against feeding these patients exists, secondary to the perception that an enormous quantity of calories is stored in adipose tissue. Making a specialty enteral formula for obesity from existing commercial formulas and other modular nutrient components is not practical, secondary to difficulty with solubility issues, dilution of the formula, and safety concerns. Using today's concepts and current metabolic data, a formula could be produced that would address many of the specific metabolic derangements noted in obesity. This formula should have a high-protein, low-carbohydrate content with at least a portion of the lipid source coming from fish oil. Specific nutrients that may be beneficial in obesity include arginine, glutamine, leucine, L-carnitine, lipoic acid, S-adenosylmethionine, and betaine. Certain trace minerals such as magnesium, zinc, and selenium may also be of value in the obese population. The concept of a specific bariatric formulation for the ICU setting is theoretically sound, is scientifically based, and could be delivered to patients safely.

The optimal lipid formulation in enteral feeding in critical illness: clinical update and review of the literature

Suitable and timely early enteral nutrition is paramount to providing optimal patient care for the critically ill. Lipids serve many essential roles throughout the human body, and are important components of most enteral formulations. This paper reviews lipid structure, function, and optimal utility for this macronutrient in enteral feeds. The use of omega-3 fatty acids has become common in critical care formulations, and their clinical efficacy is outlined separately. Available evidence is reviewed, and future directions are discussed.

Preoperative short-term parenteral administration of polyunsaturated fatty acids ameliorates intestinal inflammation and postoperative ileus in rodents

PURPOSE

Abdominal surgery results in an inflammation of the intestinal muscularis externa (ME), subsequently leading to postoperative ileus (POI). Polyunsaturated fatty acids (PUFA) are known to modulate inflammation. The aim of this study was to analyze the effect of preoperative parenteral administration of marine (n-3) or soybean (n-6) PUFA lipid emulsions (PUFA-LE) on POI and tissue fatty acid profiles.

METHODS

Rodents underwent intestinal manipulation (IM) after 5 days of parenteral administration of 10-mL/kg body weight saline, (n-3), or (n-6) PUFA-LE. Sham animals received saline treatment without IM. In rats, postoperative inflammation was quantified by ME neutrophil levels and NO production in organ culture, and ME function was determined by an in vitro contractility measurement. Additionally, in vivo gastrointestinal transit (GIT) was analyzed in mice. Lipopolysaccharide-induced IL-6 expression of rat bone marrow-derived mononuclear cells and ME was analyzed. Fatty acids were measured by gas chromatography in rat blood, bone marrow cells, and ME.

RESULTS

The (n-3) PUFA-LE reduced neutrophil levels and NO production after IM and improved in vitro jejunal contractility and GIT time. The (n-6) PUFA-LE significantly reduced postoperative inflammation and tended to improve intestinal motility (P < 0.06). Interestingly, (n-6) PUFA-LE significantly reduced the levels of arachidonic acid in ME (-63%), while (n-3) PUFA-LE reduced arachidonic acid (-20%) and additionally raised EPA (+550%).

CONCLUSION

Short-term preoperative parenteral administration of (n-3) or (n-6) PUFA-LE significantly alters tissue-specific fatty acid profiles. Preoperative parenteral PUFA-LE supplementation, preferably by marine (n-3) PUFA, ameliorates postoperative intestinal inflammation and dysmotility and could be a promising therapeutic option in POI prophylaxis.

Nutrition support for the acute lung injury/adult respiratory distress syndrome patient: a review

Support for Acute Lung Injury (ALI) and Adult Respiratory Distress Syndrome (ARDS) in many ways represents the summation of all intensive care unit nutrition modalities. Basic tenets of management are based on those established for the general population of mechanically ventilated patients. As a marker of critical illness however, patients with ALI/ARDS suffer from other organ dysfunctions that require advanced support. Specific issues to be considered in this population include carbon dioxide production, prevention of aspiration, and modulation of the inflammatory response. These particular areas, with special attention paid to the role of lipids in ALI/ARDS, will be reviewed.