Replacing saturated fatty acids with polyunsaturated fatty acids increases the abundance of Lachnospiraceae and is associated with reduced total cholesterol levels-a randomized controlled trial in healthy individuals.

BACKGROUND: Improving dietary fat quality strongly affects serum cholesterol levels and hence the risk of cardiovascular diseases (CVDs). Recent studies have identified dietary fat as a potential modulator of the gut microbiota, a central regulator of host metabolism including lipid metabolism. We have previously shown a significant reduction in total cholesterol levels after replacing saturated fatty acids (SFAs) with polyunsaturated fatty acids (PUFAs). The aim of the present study was to investigate the effect of dietary fat quality on gut microbiota, short-chain fatty acids (SCFAs), and bile acids in healthy individuals. In addition, to investigate how changes in gut microbiota correlate with blood lipids, bile acids, and fatty acids. METHODS: Seventeen participants completed a randomized, controlled dietary crossover study. The participants received products with SFAs (control) or PUFAs in random order for three days. Fecal samples for gut microbiota analyses and fasting blood samples (lipids, fatty acids, and bile acids) were measured before and after the three-day intervention. RESULTS: Of a panel of 40 bacteria, Lachnospiraceae and Bifidobacterium spp. were significantly increased after intervention with PUFAs compared with SFAs. Interestingly, changes in Lachnospiraceae, as well as Phascolarlactobacterium sp. and Eubacterium hallii, was also found to be negatively correlated with changes in total cholesterol levels after replacing the intake of SFAs with PUFAs for three days. No significant differences in SCFAs or bile acids were found after the intervention. CONCLUSION: Replacing SFAs with PUFAs increased the abundance of the gut microbiota family of Lachnospiraceae and Bifidobacterium spp. Furthermore, the reduction in total cholesterol after improving dietary fat quality correlated with changes in the gut microbiota family Lachnospiraceae. Future studies are needed to reveal whether Lachnospiraceae may be targeted to reduce total cholesterol levels. TRIAL REGISTRATION: The study was registered at Clinical Trials ( https://clinicaltrials.gov/ , registration identification number: NCT03658681).

Beneficial effect on serum cholesterol levels, but not glycaemic regulation, after replacing SFA with PUFA for 3 d: a randomised crossover trial.

Replacing intake of SFA with PUFA reduces serum cholesterol levels and CVD risk. The effect on glycaemic regulation is, however, less clear. The main objective of the present study was to investigate the short-term effect of replacing dietary SFA with PUFA on glycaemic regulation. Seventeen healthy, normal-weight participants completed a 25-d double-blind, randomised and controlled two-period crossover study. Participants were allocated to either interventions with PUFA products or SFA products (control) in a random order for three consecutive days, separated by a 1·5-week washout period between the intervention periods. Glucose, insulin and TAG were measured before and after an oral glucose tolerance test. In addition, fasting total cholesterol, NEFA and plasma total fatty acid profile were measured before and after the 3-d interventions. Fasting and postprandial glucose, insulin, and TAG levels and fasting levels of NEFA and plasma fatty acid profile did not differ between the groups. However, replacing dietary SFA with PUFA significantly reduced total cholesterol levels by 8 % after 3 d (P = 0·002). Replacing dietary SFA with PUFA for only 3 d has beneficial cardio-metabolic effects by reducing cholesterol levels in healthy individuals.

Antioxidants and phytochemicals - a scoping review for Nordic Nutrition Recommendations 2023.

Antioxidants are a collection of substances that may prevent or delay the oxidation of cellular components. The antioxidant defense system includes both endogenously produced antioxidants and dietary antioxidants. The consumption of dietary antioxidants has long been speculated to be important for the defense against cellular oxidation, inflammation, and other disease-related processes. In addition to the well-known dietary antioxidants, such as vitamin C, vitamin E, ß-carotene, and selenium, whole plants and plant-products contain numerous compounds, called phytochemicals, with antioxidant properties. These phytochemicals are potentially important modulators of oxidative stress and have been linked to health beneficial effects. However, the mechanisms underlying these potential health beneficial effects are not well understood. Foods containing high levels of phytochemicals with antioxidant properties include berries, fruits, vegetables, whole grains, and nuts and seeds. The aim of this scoping review is to describe the evidence of the role of specific antioxidants and phytochemicals, but not foods rich in these substances, for health outcomes. Based on a literature search from 2011 to March 2022, we identified eight meta-analyses related to the current topic. These studies include evidence of the effect of resveratrol (present mainly in berries, grapes, and peanuts) on health outcomes related to cardiometabolic risk, blood pressure, obesity, oxidative stress, adipokines, inflammation, and bone quality. In summary, resveratrol did elicit several health beneficial effects. However, the magnitude of effects was low, and whether the effects are related to the redox properties of resveratrol is not known. Even though there is a large body of evidence linking a plant-based diet rich in antioxidants and phytochemicals to beneficial health effects, the role of specific antioxidants and phytochemicals is still unclear.

Experiences with Gluten-Free Bread: A Qualitative Study Amongst People with Coeliac Disease Participating in a Randomised Controlled Trial.

BACKGROUND: Whole-grain bread can be an important source of fibre for people with coeliac disease (CeD) who must adhere to a gluten-free diet and avoid consuming wheat, rye and barley. Gluten-free bread frequently has a lower nutritional quality and different texture relative to gluten-containing counterparts. OBJECTIVE: The aim was to investigate experiences with gluten-free bread amongst people with CeD prior to and during a randomised controlled trial (RCT). DESIGN: We conducted individual interviews with 10 people with CeD participating in a RCT that aimed to investigate the effects of fibre-rich gluten-free products on metabolic regulation in people with CeD compared with benchmark gluten-free products. Five participants were in the control group (benchmark gluten-free bread) and five participants in the intervention group (fibre-rich gluten-free bread). The fibre-rich gluten free bread was formulated and prepared by the project group. The benchmark gluten-free bread was commercially available. The RCT lasted for four weeks. Interviews were conducted digitally between October 2021 and January 2022 and were thematically analysed. RESULTS: Participants in both groups appeared to avoid bread prior to the study, primarily due to the poor taste and chewy consistency of the available bread in food stores and bakeries. Participants preferred the fibre-rich intervention bread as opposed to the available bread in the food market. However, participants had to become accustomed to eating the fibre-rich whole-grain bread during the study, since they avoided eating store-bought bread that they experienced chewy and not filling. CONCLUSIONS: Participants asked for fibre-rich gluten-free bread products that are satiating and have a good texture. Palatable gluten-free bread products might be an important source of fibre for people with CeD.

A Three-Day Intervention With Granola Containing Cereal Beta-Glucan Improves Glycemic Response and Changes the Gut Microbiota in Healthy Individuals: A Crossover Study.

Intake of soluble fibers including beta-glucan, is known to improve post-prandial glycemic response. The mechanisms have been attributed to the viscous gel forming in the stomach and small intestine, giving a longer absorption time. However, recent evidence suggests a link between intake of beta-glucan and improved glycemic regulation at subsequent meals through the gut microbiota. We investigated the short-term effect of granola with different amounts of cereal beta-glucan on glycemic response and gut microbiota. After a two-week run-in period (baseline), fourteen healthy, normal weight adults completed a dose-response dietary crossover study. Different amounts of cereal beta-glucan (low: 0.8 g, medium: 3.2 g and high: 6.6 g) were provided in granola and eaten with 200 ml low-fat milk as an evening meal for three consecutive days. Blood glucose and insulin were measured fasted and after an oral glucose tolerance test (OGTT) the following day, in addition to peptide YY (PYY) and glucagon-like peptide (GLP-2), fasting short chain fatty acids (SCFA) in blood, breath H2, and gut microbiota in feces. Only the intervention with medium amounts of beta-glucan decreased blood glucose and insulin during OGTT compared to baseline. Fasting PYY increased with both medium and high beta-glucan meal compared to the low beta-glucan meal. The microbiota and SCFAs changed after all three interventions compared to baseline, where acetate and butyrate increased, while propionate was unchanged. Highest positive effect size after intake of beta-glucan was found with Haemophilus, followed by Veillonella and Sutterella. Furthermore, we found several correlations between different bacterial taxa and markers of glycemic response. In summary, intake of granola containing 3.2 g cereal beta-glucan as an evening meal for three consecutive days reduced the glycemic response after an OGTT 0-180 min and changed gut microbiota composition. Since we cannot rule out that other fiber types have contributed to the effect, more studies are needed to further explore the effect of cereal beta-glucan on glycemic regulation. Clinical Trial Registration: [www.clinicaltrials.gov], identifier [NCT03293693].

Attitudes towards and experiences with sourdough and baker's yeast bread amongst participants in a randomised controlled trial: a qualitative study.

Background: Bread is an important source of dietary fibre. However, an increasing number of individuals exclude bread from their habitual diet for various reasons. In recent years, sourdough bread has increased in popularity, and clinical studies have indicated that sourdough bread may decrease gastrointestinal symptoms. Objective: To investigate attitudes towards and experiences with sourdough and baker's yeast bread amongst participants in a randomised controlled trial (RCT), the health effects and consumer aspects of bread (HELFAB) study. Design: We conducted individual interviews with 10 participants who stated to be sceptical about bread and who participated in an RCT to investigate the health effects of sourdough bread versus baker's yeast bread. The participants were interviewed on two occasions (before and after the RCT). Interviews were conducted digitally between September and December 2020 and were thematically analysed. Results: Half of the interviewed participants experienced gastrointestinal symptoms, such as pain in the stomach, when they consumed bread prior to the RCT. They often preferred sourdough bread to baker's yeast bread both before and after the study, since they found that sourdough bread was easier to digest. Participants who were sceptical about bread prior to the study became more positive about bread because of their experiences with the intervention breads. This finding was mainly related to the taste and consistency of sourdough bread. The participants often associated bread with healthiness, mainly due to the dietary fibre content in bread. Conclusions: Sourdough bread with increased dietary fibre may be an important source of dietary fibre for those who perceive gastrointestinal problems from baker's yeast bread. Participants in this qualitative study stated to change their attitudes towards bread, mainly due to perceived healthiness of the intervention bread.

Gut microbiota is associated with dietary intake and metabolic markers in healthy individuals.

Background: Metabolic diseases have been related to gut microbiota, and new knowledge indicates that diet impacts host metabolism through the gut microbiota. Identifying specific gut bacteria associated with both diet and metabolic risk markers may be a potential strategy for future dietary disease prevention. However, studies investigating the association between the gut microbiota, diet, and metabolic markers in healthy individuals are scarce. Objective: We explored the relationship between a panel of gut bacteria, dietary intake, and metabolic and anthropometric markers in healthy adults. Design: Forty-nine volunteers were included in this cross-sectional study. Measures of glucose, serum triglyceride, total cholesterol, hemoglobin A1c (HbA1c), blood pressure (BP), and body mass index (BMI) were collected after an overnight fast, in addition to fecal samples for gut microbiota analyzes using a targeted approach with a panel of 48 bacterial DNA probes and assessment of dietary intake by a Food Frequency Questionnaire (FFQ). Correlations between gut bacteria, dietary intake, and metabolic and anthropometric markers were assessed by Pearson's correlation. Gut bacteria varying according to dietary intake and metabolic markers were assessed by a linear regression model and adjusted for age, sex, and BMI. Results: Of the 48 gut bacteria measured, 24 and 16 bacteria correlated significantly with dietary intake and metabolic and/or anthropometric markers, respectively. Gut bacteria including Alistipes, Lactobacillus spp., and Bacteroides stercoris differed according to the intake of the food components, fiber, sodium, saturated fatty acids, and dietary indices, and metabolic markers (BP and total cholesterol) after adjustments. Notably, Bacteroides stercoris correlated positively with the intake of fiber, grain products, and vegetables, and higher Bacteroides stercoris abundance was associated with higher adherence to Healthy Nordic Food Index (HNFI) and lower diastolic BP after adjustment. Conclusion: Our findings highlight the relationship between the gut microbiota, diet, and metabolic markers in healthy individuals. Further investigations are needed to address whether these findings are causally linked and whether targeting these gut bacteria can prevent metabolic diseases.

Effect of marine n-3 fatty acids on circulating inflammatory markers in healthy subjects and subjects with cardiovascular risk factors.

OBJECTIVE: The aim of the present paper was to review the literature in order to summarize the effects of marine n-3 fatty acids on circulating inflammatory markers among healthy subjects, subjects with high risk of developing cardiovascular disease (CVD) and in patients with CVD in human intervention studies. METHODS: A systematic literature search in PubMed was performed. Intervention studies describing the effects of marine n-3 fatty acids on circulating inflammatory markers in healthy subjects, subjects with high risk of CVD and patients with CVD were included. The following exclusion criteria were used: (1) interventions assessing inflammatory markers with ex vivo methods (2) interventions with children (3) articles describing animal or cell culture studies. Twenty-two articles were included. Additionally, 13 papers from their literature lists were included based on the same inclusion and exclusion criteria as the literature search. RESULTS AND CONCLUSION: Intervention studies with marine n-3 fatty acids administered from either fish or fish oil demonstrate different results on inflammatory markers. No firm conclusion can be drawn about the effect of marine n-3 fatty acids on circulating inflammatory markers in healthy individuals, individuals with high risk of developing CVD or individuals with CVD related diseases.

Effect of the fat composition of a single high-fat meal on inflammatory markers in healthy young women.

The aim of the present study was to examine the effect of a single high-fat meal with different fat quality on circulating inflammatory markers and gene expression in peripheral blood mononuclear cells (PBMC) to elucidate the role of fat quality on postprandial inflammation. A postprandial study with fourteen healthy females consuming three test meals with different fat quality was performed. Test days were separated by 2 weeks. Fasting and postprandial blood samples at 3 and 6 h after intake were analysed. The test meal consisted of three cakes enriched with coconut fat (43 % energy as saturated fat and 1 % energy as α-linolenic acid (ALA)), linseed oil (14 % energy as ALA and 30 % energy as saturated fat) and cod liver oil (5 % energy as EPA and DHA and 5 % energy as ALA in addition to 31 % energy as saturated fat). In addition, ex vivo PBMC experiments were performed in eight healthy subjects investigating the effects of EPA and ALA on release and gene expression of inflammatory markers. The IL-8 mRNA level was significantly increased after intake of the cod liver oil cake at 6 h compared with fasting level, which was significantly different from the effect observed after the intake of linseed cake. In contrast, no effect was seen on circulating level of IL-8. In addition, ALA and EPA were shown to elicit different effects on the release and mRNA expression levels of inflammatory markers in PBMC cultured ex vivo, with EPA having the most prominent pro-inflammatory potential.

Nutritional quality and costs of gluten-free products: a case-control study of food products on the Norwegian marked.

BACKGROUND: Celiac disease is a chronic autoimmune disease triggered by gluten exposure in genetically predisposed individuals. A life-long intake of a gluten-free (GF) diet is required for its management. Wheat, rye and barley are eliminated in a GF diet and the nutritional adequacy of the diet has been questioned. In Norway, cereals and bread constitute a key role of the diet and are the main source of fiber intake. Gluten restrictions may therefore offer important implications for nutrient adequacy especially linked to fiber intake in people with celiac disease. OBJECTIVE: The aim of the study was to investigate the nutritional quality and price of GF products and compare with gluten-containing counterparts available at instead of in the Norwegian market. DESIGN: The macronutrient content of 423 unique GF products were compared with 337 equivalents with gluten. All products were selected from grocery stores and web-based shops, with the aim of including as many GF products as possible. Listed macronutrients content and price in 11 different food categories were compared to gluten-containing counterparts with Wilcoxon signed rank test. RESULTS: The GF products contained less protein and fiber, and higher content of saturated fat, carbohydrate and salt compared to the gluten-containing products. The total amount of fat was not different between the groups. A similar pattern was found within several of the food categories. More gluten-containing products met the nutrition claim "high in fiber" (fiber > 6 g/100 g) compared to the GF products. The price of the GF products was higher; ranging from 46%-443% more expensive than the gluten-containing products. CONCLUSION: GF products are less nutritious and have a higher price compared to equivalent gluten-containing products. Knowing that an unhealthy diet is the most important risk factor for developing non-communicable diseases, the nutritional quality of a GF diet needs to be addressed and should be improved.

Bilberry/red grape juice decreases plasma biomarkers of inflammation and tissue damage in aged men with subjective memory impairment -a randomized clinical trial.

BACKGROUND: Few randomized clinical trials have explored the health effects of bilberries in humans. The aim was to test the effect of bilberry and red grape-juice consumption on visual memory, motor speed and dexterity as well as inflammatory and tissue damage biomarkers of plasma in aged men with subjective memory impairment. METHODS: Nine-week double-blind, placebo-controlled, dietary intervention study of aged men (n = 60, age ≥ 67 years) with subjective memory impairment randomized to consume a 50/50 mix of bilberry/red grape-juice or an iso-caloric placebo juice. A selection of Cambridge Cognition Test Battery (CANTAB), Grooved Pegboard tests and blood-sampling for biomarker analysis were performed before and after the intervention. RESULTS: Compared to placebo the selected memory and motor test scores were un-affected by the bilberry/red grape intervention. However, the plasma levels of tissue damage biomarkers decreased significantly more in the bilberry/red grape group. In particular lactate dehydrogenase (LDH) decreased from 362 U/L (median, baseline) to 346 U/L (median, post intervention) in the bilberry/red grape group. Also, several biomarkers of inflammation (EGF, IL6, IL9, IL10 and TNFα) decreased significantly more in the bilberry/red grape group. Furthermore, several plasma polyphenols; p-coumaric acid, hippuric acid, protocatechuic acid, 3HPAA and vanillic acid, increased significantly more in the bilberry/red grape group compared to placebo with the largest increase in p-coumaric acid with 116%; from 2.2 [1.0,5.5] to 4.7 [2.8,8.1] µM/L (median [95% CL]). CONCLUSIONS: The results indicate that a nine-week bilberry/red grape juice intervention has no measurable effects on the selected memory scores in aged men experiencing memory problems but decreases the level of biomarkers of inflammation and tissue damage. Whether the dampening effects on inflammation and tissue damage biomarkers have relevance for neuroinflammatory brain pathology remains to be established. TRIAL REGISTRATION: Registration number ( ClinicalTrials.gov : NCT00972972 ), September 9, 2009.

Apple, cherry, and blackcurrant increases nuclear factor kappa B activation in liver of transgenic mice.

Nuclear factor kappa B (NF-kappaB) is essential in normal physiology, and several human disorders involve inappropriate regulation of NF-kappaB. Diets dominated by plant-based foods protect against chronic diseases, and several food derived compounds have been identified as promising NF-kappaB modulators. We investigated the effects of diets supplemented with apple, blackcurrant, or cherries on lipopolysaccharide (LPS)-induced NF-kappaB activation in transgenic NF-kappaB-luciferase mice. Whole body and organ specific NF-kappaB activities were determined. The mice had ad libitum access to the respective experimental diets for 7 days. On Day 7, all mice were given an LPS-injection (2.5 mg/kg), and NF-kappaB activation was monitored by in vivo imaging for 6 h. After imaging, blood samples were taken, the mice were euthanized, and ex vivo imaging of organs was performed. Compared to the control group, the apple and cherry groups had slightly higher whole-body NF-kappaB activation at 4 h, and all 3 experimental groups had higher NF-kappaB activation at 6 h. LPS-induced NF-kappaB activation in liver was increased with all 3 experimental diets, but no effects were observed in other organs. Our findings indicate that high intakes of lyophilized fruits modulate in vivo NF-kappaB signaling in the liver following LPS-induced stress; however, consequences of this NF-kappaB modulation in hepatic tissue needs further investigation.

Dietary Fiber, Gut Microbiota, and Metabolic Regulation-Current Status in Human Randomized Trials.

New knowledge about the gut microbiota and its interaction with the host's metabolic regulation has emerged during the last few decades. Several factors may affect the composition of the gut microbiota, including dietary fiber. Dietary fiber is not hydrolyzed by human digestive enzymes, but it is acted upon by gut microbes, and metabolites like short-chain fatty acids are produced. The short-chain fatty acids may be absorbed into the circulation and affect metabolic regulation in the host or be a substrate for other microbes. Some studies have shown improved insulin sensitivity, weight regulation, and reduced inflammation with increases in gut-derived short-chain fatty acids, all of which may reduce the risk of developing metabolic diseases. To what extent a dietary intervention with fiber may affect the human gut microbiota and hence metabolic regulation, is however, currently not well described. The aim of the present review is to summarize recent research on human randomized, controlled intervention studies investigating the effect of dietary fiber on gut microbiota and metabolic regulation. Metabolic regulation is discussed with respect to markers relating to glycemic regulation and lipid metabolism. Taken together, the papers on which the current review is based, suggest that dietary fiber has the potential to change the gut microbiota and alter metabolic regulation. However, due to the heterogeneity of the studies, a firm conclusion describing the causal relationship between gut microbiota and metabolic regulation remains elusive.

Experiences of managing a gluten-free diet on multiple levels of society: a qualitative study.

BACKGROUND: Coeliac disease (CD) is an immune-mediated enteropathy against dietary gluten. The treatment for CD is a strict life-long gluten-free (GF) diet, which has a profound effect on a person's life. In recent years, there has been an increase in the availability of gluten-free products. This study investigates how people with CD experience and manage a GF diet. METHODS: Semi-structured, individual interviews were conducted in different areas of Norway. The analysis was guided by Interpretative Phenomenological Analysis. Participants with CD (n = 12) varied in terms of gender, age, family composition and time since diagnosed. RESULTS: The analysis revealed challenges for a GF diet at the individual, interpersonal, community and policy levels. At the individual level, the participants explained that it took time to gain knowledge about a GF diet, and they expressed uncertainty about the healthiness of a GF diet. At the interpersonal level, the feeling of being different and the fear of gluten contamination were barriers to the enjoyment of social meals. At the community level, the participants asked for a wider selection of tastier GF products to purchase and increased knowledge about CD among those who prepare and sell GF foods. At the policy level, the participants asked for political action to make GF products more affordable. CONCLUSIONS: This study indicates that people with CD should be given information about how to manage a GF diet right after being diagnosed with CD. The food industry should be encouraged to produce healthy and tasty GF products.

Polyunsaturated Fatty Acids and Glycemic Control in Type 2 Diabetes.

The impact of dietary fat on the risk of cardiovascular disease (CVD) has been extensively studied in recent decades. Solid evidence indicates that replacing saturated fatty acids (SFAs) with polyunsaturated fatty acids (PUFAs) decreases blood cholesterol levels and prevents CVD and CVD mortality. Studies indicate that fat quality also may affect insulin sensitivity and hence, the risk of type 2 diabetes (T2D). A high intake of SFAs has shown to increase the risk of T2D in prospective studies, while a high intake of PUFAs reduces the risk. Whether PUFAs from marine or vegetable sources affect glycemic regulation differently in T2D remains to be elucidated. The aim of the present review was therefore to summarize research on human randomized, controlled intervention studies investigating the effect of dietary PUFAs on glycemic regulation in T2D. About half of the studies investigating the effect of fish, fish oils, vegetable oils, or nuts found changes related to glycemic control in people with T2D, while the other half found no effects. Even though some of the studies used SFA as controls, the majority of the included studies compared PUFAs of different quality. Considering that both marine and vegetable oils are high in PUFAs and hence both oils may affect glycemic regulation, the lack of effect in several of the included studies may be explained by the use of an inappropriate control group. It is therefore not possible to draw a firm conclusion, and more studies are needed.

An Isocaloric Nordic Diet Modulates RELA and TNFRSF1A Gene Expression in Peripheral Blood Mononuclear Cells in Individuals with Metabolic Syndrome-A SYSDIET Sub-Study.

A healthy dietary pattern is associated with a lower risk of metabolic syndrome (MetS) and reduced inflammation. To explore this at the molecular level, we investigated the effect of a Nordic diet (ND) on changes in the gene expression profiles of inflammatory and lipid-related genes in peripheral blood mononuclear cells (PBMCs) of individuals with MetS. We hypothesized that the intake of an ND compared to a control diet (CD) would alter the expression of inflammatory genes and genes involved in lipid metabolism. The individuals with MetS underwent an 18/24-week randomized intervention to compare a ND with a CD. Eighty-eight participants (66% women) were included in this sub-study of the larger SYSDIET study. Fasting PBMCs were collected before and after the intervention and changes in gene expression levels were measured using TaqMan Array Micro Fluidic Cards. Forty-eight pre-determined inflammatory and lipid related gene transcripts were analyzed. The expression level of the gene tumor necrosis factor (TNF) receptor superfamily member 1A (TNFRSF1A) was down-regulated (p = 0.004), whereas the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) subunit, RELA proto-oncogene, was up-regulated (p = 0.016) in the ND group compared to the CD group. In conclusion, intake of an ND in individuals with the MetS may affect immune function.

Healthy Nordic Diet Modulates the Expression of Genes Related to Mitochondrial Function and Immune Response in Peripheral Blood Mononuclear Cells from Subjects with Metabolic Syndrome-A SYSDIET Sub-Study.

SCOPE: To explore the effect of a healthy Nordic diet on the global transcriptome profile in peripheral blood mononuclear cells (PBMCs) of subjects with metabolic syndrome. METHODS AND RESULTS: Subjects with metabolic syndrome undergo a 18/24 week randomized intervention study comparing an isocaloric healthy Nordic diet with an average habitual Nordic diet served as control (SYSDIET study). Altogether, 68 participants are included. PBMCs are obtained before and after intervention and total RNA is subjected to global transcriptome analysis. 1302 probe sets are differentially expressed between the diet groups (p-value < 0.05). Twenty-five of these are significantly regulated (FDR q-value < 0.25) and are mainly involved in mitochondrial function, cell growth, and cell adhesion. The list of 1302 regulated probe sets is subjected to functional analyses. Pathways and processes involved in the mitochondrial electron transport chain, immune response, and cell cycle are downregulated in the healthy Nordic diet group. In addition, gene transcripts with common motifs for 42 transcription factors, including NFR1, NFR2, and NF-κB, are downregulated in the healthy Nordic diet group. CONCLUSION: These results suggest that benefits of a healthy diet may be mediated by improved mitochondrial function and reduced inflammation.

Correction to: Plasma fatty acid levels and gene expression related to lipid metabolism in peripheral blood mononuclear cells: a cross-sectional study in healthy subjects.

[This corrects the article DOI: 10.1186/s12263-018-0600-z.].

Plasma fatty acid levels and gene expression related to lipid metabolism in peripheral blood mononuclear cells: a cross-sectional study in healthy subjects.

BACKGROUND: Solid evidence indicates that intake of marine n-3 fatty acids lowers serum triglycerides and that replacing saturated fatty acids (SFA) with polyunsaturated fatty acids (PUFA) reduces plasma total cholesterol and LDL cholesterol. The molecular mechanisms underlying these health beneficial effects are however not completely elucidated. The aim of this study was therefore to investigate the expression of genes related to lipid metabolism in peripheral blood mononuclear cells (PBMC) depending on the plasma levels of n-6 and n-3 fatty acids and the SFA to PUFA ratio. METHODS: Fifty-four healthy subjects were grouped into tertiles (n = 18) based on plasma levels of n-6 and n-3 fatty acids and the SFA to PUFA ratio. The PBMC gene expression levels among subjects in the highest versus the lowest tertiles were compared. In total, 285 genes related to cholesterol and triglyceride metabolism were selected for this explorative study. RESULTS: Among the 285 selected genes, 161 were defined as expressed in the PBMCs. The plasma SFA to PUFA ratio was associated with the highest number of significantly different expressed genes (25 gene transcripts), followed by plasma n-6 fatty acid level (15 gene transcripts) and plasma n-3 fatty acid level (8 gene transcripts). In particular, genes involved in cholesterol homeostasis were significantly different expressed among subjects with high compared to low plasma SFA to PUFA ratio. CONCLUSION: Genes involved in lipid metabolism were differentially expressed in PBMCs depending on the plasma fatty acid levels. This finding may increase our understanding of how fatty acids influence lipid metabolism at a molecular level in humans.

Lack of Effects of a Single High-Fat Meal Enriched with Vegetable n-3 or a Combination of Vegetable and Marine n-3 Fatty Acids on Intestinal Peptide Release and Adipokines in Healthy Female Subjects.

Peptides released from the small intestine and colon regulate short-term food intake by suppressing appetite and inducing satiety. Intake of marine omega-3 (n-3) fatty acids (FAs) from fish and fish oils is associated with beneficial health effects, whereas the relation between intake of the vegetable n-3 fatty acid α-linolenic acid and diseases is less clear. The aim of the present study was to investigate the postprandial effects of a single high-fat meal enriched with vegetable n-3 or a combination of vegetable and marine n-3 FAs with their different unsaturated fatty acid composition on intestinal peptide release and the adipose tissue. Fourteen healthy lean females consumed three test meals with different fat quality in a fixed order. The test meal consisted of three cakes enriched with coconut fat, linseed oil, and a combination of linseed and cod liver oil. The test days were separated by 2 weeks. Fasting and postprandial blood samples at 3 and 6 h after intake were analyzed. A significant postprandial effect was observed for cholecystokinin, peptide YY, glucose-dependent insulinotropic polypeptide, amylin and insulin, which increased, while leptin decreased postprandially independent of the fat composition in the high-fat meal. In conclusion, in healthy, young, lean females, an intake of a high-fat meal enriched with n-3 FAs from different origin stimulates intestinal peptide release without any difference between the different fat compositions.