Measurement of postprandial interleukin-6 by using a catheter: what does it tell us?

Temporal changes in postprandial blood transcriptomes reveal subject-specific pattern of expression of innate immunity genes after a high-fat meal

White blood cells are among the first responders to dietary components and their metabolites absorbed from the gut. The objective of this study was to determine the whole blood transcriptome response to high-fat challenge meals. A total of 45 fasting and postprandial (3-h and 6-h) whole blood transcriptomes from 5 subjects in a crossover intervention trial of a high-fat meal supplemented with placebo, blueberry powder or docosahexaenoic acid (DHA) were analyzed using RNA sequencing. Select target genes were validated by quantitative reverse-transcription polymerase chain reaction in 180 samples from 20 subjects. The largest contributor to variance was the subject (13,856 genes differentially expressed), followed by the subject on a specific day (2276 genes), followed by the subject's postprandial response (651 genes). After determining the nonsignificance of individual dietary treatments (blueberry, DHA, placebo), treatments were used as replicates to examine postprandial responses to a high-fat meal. The universal postprandial response (95 genes) was associated with lipid utilization, fatty acid beta-oxidation and circadian rhythms. Subject-specific postprandial responses were enriched for genes involved in the innate immune response, particularly those of pattern recognition receptors and their downstream signaling components. Genes involved in innate immune responses are differentially expressed in a subject-specific and time-dependent manner in response to the high-fat meals. These genes can serve as biomarkers to assess individual responsiveness to a high-fat diet in inducing postprandial inflammation. Furthermore, the dynamic temporal change in gene expression in postprandial blood suggests that monitoring these genes at multiple time points is necessary to reveal responders to dietary intervention.

Metabolic status is related to the effects of adding of sacha inchi (Plukenetia volubilis L.) oil on postprandial inflammation and lipid profile: Randomized, crossover clinical trial

Sacha inchi oil (SIO) is an attractive source of polyunsaturated acids oil. A randomized crossover clinical trial was done to evaluate SIO effects on postprandial lipids and inflammatory state caused by a high-fat intake. Twenty metabolically healthy (MH) and 22 metabolically unhealthy (MU) subjects consumed a high-fat breakfast alone or supplemented with SIO. The biomarkers were measured in serum upon fasting, and after 1 and 4 hrs after breakfast. Interleukin-6 (IL-6) expression was determined in mononuclear cells. In the MH group, SIO reversed the cholesterol increase [iAUC_HFM : 0.27 mmol/L/4 h (IQR: -0.07/0.81); iAUC_HFM+S : -0.18 mmol/L/4 h (IQR: -0.49/0.31) p = 0.037] and decreased interleukin-6 concentration. In MU group, SIO attenuated lipopolysaccharides increase and interleukin-6 expression [(FC_HFM  = -1.19 (IQR: -1.72/1.93) and FC_HFM+S  = -1.83 (IQR: -4,82/-0.01), p = 0.017]. The effects of a high-fat meal on postprandial lipids and inflammation could be modified by the addition of SIO, but the outcomes are depending on the metabolic individual status. PRACTICAL APPLICATIONS: The seeds of Plukenetia volubilis L., also known as Sacha inchi, Sacha peanut or Inca peanut are an attractive vegetable source of oil which includes a high content of polyunsaturated fatty acids. Furthermore, the intake of Sacha inchi oil could improve the postprandial responses of a high-fat intake, and could be able to help to prevent cardiovascular diseases. Our results contribute to know the effects of this oil on postprandial inflammation and lipids. In addition, establishing how a person's basal metabolic status can determinate the metabolic response to this oil can help improve its use, and our results add evidence about the role of nutrition and diet in health and disease. At this time, the cultivation of Sacha inchi is being proposed as an agro-industrial alternative for the improvement of quality of living in Colombian rural areas.

The acute effects of walking exercise intensity on systemic cytokines and oxidative stress

Purpose

Oxidative stress is associated with tissue cytokine secretion although the precise mechanism(s) underpinning this relationship during high intensity intermittent exercise remains unclear. This study investigates the acute response to a bout of high intensity intermittent walking (HIIW), compared to continuous moderate intensity walking (CMW), on various cytokines and biomarkers of oxidative stress.

Methods

Seventeen (n = 17) apparently healthy male participants (aged 22.6 ± 4.6 years; \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{2} \max$$\end{document}V˙O2max: 53.7 ± 7.1 ml kg⁻¹ min⁻¹) undertook a randomised crossover study consisting of two exercise trials: (1) HIIW requiring 3 × 5 min bursts at 80% \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{2} \max$$\end{document}V˙O2max (each separated by 5 min of walking at 30% \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{2} \max$$\end{document}V˙O2max) and (2) CMW (60% \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{2} \max$$\end{document}V˙O2max for 30 min). Each trial was separated by 7 days. Venous blood samples were obtained pre-exercise, post-exercise and at 2, 4, 24 and 48 h post-exercise for determination of systemic inflammation (IL-6 and TNF-α), lipid soluble antioxidants and oxidative stress (LOOH, H₂O₂ and the ascorbyl free radical).

Results

Both IL-6 and TNF-α increased immediately post exercise, regardless of intensity and remained elevated until at least 4 h (main effect for time; p < 0.05). While there was no change in either lipid peroxidation or free radical metabolism (Asc· and H₂O₂), α-tocopherol increased (pooled HIIW and CMW, p < 0.05), whereas lycopene decreased at 2 h post HIIW (p < 0.05).

Conclusion

Bouts of both HIIW and CMW promote cytokine secretion post exercise, and this seems to be independent of oxidative stress. Further investigation is required to assess how such changes may underpin some of the transient health benefits of exercise.