Potential Complementary Effect of Zinc and Alkalihalobacillus clausii on Gut Health and Immunity: A Narrative Review.

A balanced microbiota-microorganisms that live in the gut-is crucial in the early years of a child's life, while dysbiosis-altered microbiota-has been linked to the development of various diseases. Probiotics, such as Alkalihalobacillus clausii, are commonly used to restore the balance of gut microbiota and have shown additional antimicrobial and immunomodulatory properties. Intake of micronutrients can affect the structure and function of the gut barrier and of the microbiota by having multiple effects on cellular metabolism (e.g., immunomodulation, gene expression, and support structure proteins). An inadequate zinc intake increases the risk of deficiency and associated immune dysfunctions; it is responsible for an increased risk of developing gastrointestinal diseases, respiratory infections, and stunting. Paediatric zinc deficiency is a public health concern in many countries, especially in low-income areas. Currently, zinc supplementation is used to treat childhood diarrhoea. This review examines how combining A. clausii and zinc could improve dysbiosis, gut health, and immunity. It suggests that this combination could be used to prevent and treat infectious diseases and diarrhoea in children up to adolescence.

Effect of a Combination of Magnesium, B Vitamins, Rhodiola, and Green Tea (L-Theanine) on Chronically Stressed Healthy Individuals-A Randomized, Placebo-Controlled Study.

The effect of a combination of magnesium, vitamins B6, B9, B12, rhodiola and green tea/L-theanine (Mg-Teadiola) on stress was evaluated in chronically stressed, otherwise healthy individuals. Effects on stress-related quality-of-life parameters (sleep and perception of pain) were also explored. Adults with stress for ≥1 month, scoring ≥14 points on the Depression Anxiety Stress Scale (DASS)-42 questionnaire, were randomized (1:1) to receive oral Mg-Teadiola (n = 49) or a placebo (n = 51), for 28 days, with a follow-up assessment on Day 56 (NCT04391452). The primary endpoint was the change in the DASS-42 stress score from baseline to Day 28 with Mg-Teadiola versus placebo. The DASS-42 stress scores significantly decreased from baseline to Day 28 with Mg-Teadiola versus placebo (effect size, 0.29; 95% CI [0.01, 0.57]; p = 0.04). Similar reductions were observed on Day 14 (p = 0.006) and Day 56 (p = 0.02). A significant reduction in sensitivity to cold pain (p = 0.01) and a trend for lower sensitivity to warm pain was observed (p = 0.06) on Day 28. Improvements in daytime dysfunction due to sleepiness (Pittsburgh Sleep Quality Index-7 component score) were reported on Day 28, and were significant on Day 56 (p < 0.001). Mg-Teadiola is effective in managing stress in otherwise healthy individuals. Its beneficial effects on sleep and pain perception need further investigation.

Reduced Self-Perception of Fatigue after Intake of Panax ginseng Root Extract (G115®) Formulated with Vitamins and Minerals-An Open-Label Study.

BACKGROUND: Unexplained fatigue is a common complaint. When underlying disease causes have been eliminated, lifestyle measures and supplementation can be indicated. Elaborating on clinical findings that G115®, a dry extract from the root of Panax ginseng, combined with vitamins and minerals could alleviate fatigue, this open label study aimed at assessing its effect on perceived fatigue and energy. METHODS: Healthy adults self-reporting fatigue (n = 103) completed the Multidimensional Fatigue Inventory questionnaire. They rated their perceptions of mental and physical fatigue, energy, performance, and stress at baseline and 15, 30, 60 and 90 days after a daily intake of 40 mg G115® formulated with vitamins and minerals. RESULTS: Compared with baseline values, mean self-perception of general fatigue was reduced by -7.55 units [95% CI: -8.44; -6.66] (-41.8%, p < 0.0001) at 90 days. All assessed perception ratings (mental and physical fatigue, reduced activity and motivation, performance, and stress) were significantly and steadily improved from two weeks after supplementation up to study's end. Overall satisfaction with the ability of the product to reduce fatigue reached 85% at Day 90. CONCLUSION: Daily intake with G115® extract formulated with vitamins and minerals suggests an improvement of self-perception of fatigue and energy in a fatigued adult population.

Effect of magnesium and vitamin B6 supplementation on mental health and quality of life in stressed healthy adults: Post-hoc analysis of a randomised controlled trial.

Magnesium status and vitamin B6 intake have been linked to mental health and/or quality of life (QoL). In an 8-week Phase IV randomised controlled study in individuals with low magnesemia and severe/extremely severe stress but who were otherwise healthy, greater stress reduction was achieved with magnesium combined with vitamin B6 than with magnesium alone. We present a previously unreported secondary analysis of the effect of magnesium, with and without vitamin B6, on depression, anxiety, and QoL. Adults with Depression Anxiety Stress Scales (DASS-42) stress subscale score >18 were randomised 1:1 to magnesium + vitamin B6 combination (Magne B6® ; daily dose 300 and 30 mg, respectively) or magnesium alone (Magnespasmyl® ; daily dose 300 mg). Outcomes included changes from baseline in DASS-42 depression and anxiety scores, and QoL (Short Form-36 Health Survey). DASS-42 anxiety and depression scores significantly improved from baseline to week 8 with both treatments, particularly during the first 4 weeks. Improvement in QoL continued over 8 weeks. Participants' perceived capacity for physical activity in daily life showed greater improvement with magnesium + vitamin B6 than magnesium alone (Week 4). In conclusion, magnesium supplementation, with or without vitamin B6, could provide a meaningful clinical benefit in daily life for individuals with stress and low magnesemia.

Magnesium Status and Stress: The Vicious Circle Concept Revisited.

Magnesium deficiency and stress are both common conditions among the general population, which, over time, can increase the risk of health consequences. Numerous studies, both in pre-clinical and clinical settings, have investigated the interaction of magnesium with key mediators of the physiological stress response, and demonstrated that magnesium plays an inhibitory key role in the regulation and neurotransmission of the normal stress response. Furthermore, low magnesium status has been reported in several studies assessing nutritional aspects in subjects suffering from psychological stress or associated symptoms. This overlap in the results suggests that stress could increase magnesium loss, causing a deficiency; and in turn, magnesium deficiency could enhance the body's susceptibility to stress, resulting in a magnesium and stress vicious circle. This review revisits the magnesium and stress vicious circle concept, first introduced in the early 1990s, in light of recent available data.

Impact of magnesium supplementation, in combination with vitamin B6, on stress and magnesium status: secondary data from a randomized controlled trial.

Primary findings from a recent study reported that magnesium supplementation significantly reduced stress in severely stressed subjects with low magnesemia, and additional vitamin B6 enhanced this effect. The mechanism by which combining magnesium and vitamin B6 leads to reduced stress in these subjects remains to be elucidated. This secondary analysis investigated the impact of magnesium and vitamin B6 supplementation and perceived stress on erythrocyte magnesium levels, as a marker of body magnesium status. This was a secondary analysis from an 8-week randomized controlled trial comparing oral magnesium (300 mg) and magnesium-vitamin B6 (300 mg + 30 mg) supplementation. Stress level and erythrocyte magnesium level at baseline, and change in erythrocyte magnesium and serum vitamin B6 levels at weeks 4 and 8, were analyzed. Overall, 264 subjects were randomized to treatment and had evaluable Depression Anxiety Stress Scale scores (132 in each treatment arm). At baseline, stress scores, and mean serum magnesium, erythrocyte magnesium, and serum vitamin B6 concentrations were similar between arms. Although not significant between groups, a significant increase over time in erythrocyte magnesium levels was observed in the subgroup of subjects with low baseline erythrocyte magnesium levels (<1.6 mmol/L) following treatment with magnesium and magnesium-vitamin B6 (week 4:0.21 mmol/L [95% confidence interval (CI), 0.10 to 0.31], p = 0.0003; and 0.13 mmol/L [95% CI, 0.02 to 0.23], p = 0.0233, respectively). Change from baseline in circulating vitamin B6 levels at weeks 4 and 8 in the magnesium-vitamin B6 supplemented group (314.96 nmol/L [95%CI, 294.61 to 335.31]) was significantly different (p < 0.0001) compared with the magnesium supplemented group (-0.39 nmol/L [95% CI, -20.73 to 19.94]). Magnesium alone and magnesium-vitamin B6 provided statistically significant increases in erythrocyte magnesium in subjects with low magnesium status (<1.6mmol/L). Vitamin B6 supplementation did not further increase magnesium levels.

Relative bioavailability and pharmacokinetic comparison of calcium glucoheptonate with calcium carbonate.

Adequate calcium intake is important for the prevention of bone loss and osteoporosis. For some populations such as those of Southeast Asia where calcium intake is very low, supplements represent a suitable dietary source of calcium. The objective of this study was to compare the relative oral bioavailability of calcium from calcium glucoheptonate, a highly soluble calcium salt containing 8.2% of elemental calcium, to that of calcium carbonate. A single-dose, randomized-sequence, open-label, two-period crossover study, with a 7-day washout period, was conducted in 24 Indonesian healthy adult volunteers. After a 12-hour (overnight) fast, subjects received either two oral ampoules of 250 mg/10 mL of calcium glucoheptonate each or one effervescent tablet of calcium carbonate containing 500 mg of elemental calcium. The relative oral bioavailability of calcium from calcium glucoheptonate as compared to calcium carbonate was 92% within 6 hours and 89% within 12 hours after study drug administration. The 90% confidence intervals for the mean test/reference ratios of the maximum plasma concentration and the area under the concentration-time curve at 12 hours post-administration were 77.09%-120.31% and 60.58%-122.30%, respectively. Five subjects experienced a total of eight adverse events which were all mild and transient; no serious adverse events or deaths were reported. These results indicate that calcium glucoheptonate is associated with a high relative bioavailability of calcium compared to calcium carbonate, and is well-tolerated. Calcium glucoheptonate might thus be a potential choice for calcium supplementation in Southeast Asian populations.

Vitamins and Minerals for Energy, Fatigue and Cognition: A Narrative Review of the Biochemical and Clinical Evidence.

Vitamins and minerals are essential to humans as they play essential roles in a variety of basic metabolic pathways that support fundamental cellular functions. In particular, their involvement in energy-yielding metabolism, DNA synthesis, oxygen transport, and neuronal functions makes them critical for brain and muscular function. These, in turn, translate into effects on cognitive and psychological processes, including mental and physical fatigue. This review is focused on B vitamins (B1, B2, B3, B5, B6, B8, B9 and B12), vitamin C, iron, magnesium and zinc, which have recognized roles in these outcomes. It summarizes the biochemical bases and actions of these micronutrients at both the molecular and cellular levels and connects them with cognitive and psychological symptoms, as well as manifestations of fatigue that may occur when status or supplies of these micronutrients are not adequate.

Superiority of magnesium and vitamin B6 over magnesium alone on severe stress in healthy adults with low magnesemia: A randomized, single-blind clinical trial.

INTRODUCTION: Animal and clinical studies suggest complementary effects of magnesium and high-dose pyridoxine (vitamin B6) on stress reduction. This is the first randomized trial evaluating the effects of combined magnesium and vitamin B6 supplementation on stress in a stressed population with low magnesemia using a validated measure of perceived stress. METHODS: In this Phase IV, investigator-blinded trial (EudraCT: 2015-003749-24), healthy adults with Depression Anxiety Stress Scales (DASS-42) stress subscale score >18 and serum magnesium concentration 0.45 mmol/L-0.85 mmol/L, were randomized 1:1 to magnesium-vitamin B6 combination (Magne B6 [Mg-vitamin B6]; daily dose 300 mg and 30 mg, respectively) or magnesium alone (Magnespasmyl [Mg]; daily dose 300 mg). Outcomes included change in DASS-42 stress subscale score from baseline to Week 8 (primary endpoint) and Week 4, and incidence of adverse events (AEs). RESULTS: In the modified intention-to-treat analysis (N = 264 subjects), both treatment arms substantially reduced DASS-42 stress subscale score from baseline to Week 8 (Mg-vitamin B6, 44.9%; Mg 42.4%); no statistical difference between arms was observed (p>0.05). An interaction (p = 0.0097) between baseline stress level and treatment warranted subgroup analysis (as per statistical plan); adults with severe/extremely severe stress (DASS-42 stress subscale score ≥25; N = 162) had a 24% greater improvement with Mg-vitamin B6 versus Mg at Week 8 (3.16 points, 95% CI 0.50 to 5.82, p = 0.0203). Consistent results were observed in the per protocol analysis and at Week 4. Overall, 12.1% of Mg-vitamin B6 treated and 17.4% of Mg-treated subjects experienced AEs potentially treatment related. CONCLUSIONS: These findings suggest oral Mg supplementation alleviated stress in healthy adults with low magnesemia and the addition of vitamin B6 to Mg was not superior to Mg supplementation alone. With regard to subjects with severe/extremely severe stress, this study provides clinical support for greater benefit of Mg combined with vitamin B6.

Natural carbon isotope abundance of plasma metabolites and liver tissue differs between diabetic and non-diabetic Zucker diabetic fatty rats.

BACKGROUND: 'You are what you eat' is an accurate summary for humans and animals when it comes to carbon isotope abundance. In biological material, natural(13)C/(12)C ratio is subject to minute variations due to diet composition (mainly from ingestion of C3 and C4 metabolism plants) and to the discrimination between 'light' and 'heavy' isotopes during biochemical reactions (isotope effects and isotopic fractionation). METHODOLOGY/PRINCIPAL FINDINGS: Carbon isotopic abundance was measured in ZDF (fa/+) and ZDF (fa/fa), (lean and obese-diabetic rats respectively) fed the same diet. By analysing plasma metabolites (glucose and non-esterified fatty acids), breath and liver tissue by high-precision isotope ratio mass spectrometry, we demonstrate for the first time statistically distinguishable metabolic carbon isotope abundance between ZDF (fa/+) and ZDF (fa/fa) rats based on plasma glucose, palmitic, oleic, linoleic, arachidonic acids and bulk analysis of liver tissue (P<0.005) resulting into clear isotopic fingerprints using principal component analysis. We studied the variation of isotopic abundance between both groups for each metabolite and through the metabolic pathways using the precursor/product approach. We confirmed that lipids were depleted in (13)C compared to glucose in both genotypes. We found that isotopic abundance of linoleic acid (C18: 2n-6), even though both groups had the same feed, differed significantly between both groups. The likely reason for these changes between ZDF (fa/+) and ZDF (fa/fa) are metabolic dysregulation associated with various routing and fluxes of metabolites. CONCLUSION/SIGNIFICANCE: This work provides evidence that measurement of natural abundance isotope ratio of both bulk tissue and individual metabolites can provide meaningful information about metabolic changes either associated to phenotype or to genetic effects; irrespective of concentration. In the future measuring the natural abundance δ(13)C of key metabolites could be used as endpoints for studying in vivo metabolism, especially with regards to metabolic dysregulation, and development and progression of metabolic diseases.

The guinea pig as a model for metabolic programming of adiposity.

BACKGROUND: The human infant accumulates body fat during intrauterine life. The guinea pig shares this characteristic and is born with similar adiposity; thus, it may be a relevant model to study obesity programming. OBJECTIVE: The objective of this study was to evaluate guinea pig adipose tissue (AT) development and the effect of a maternal high-fat diet on the offspring's body composition. DESIGN: In experiment 1, adipogenesis dynamics were evaluated at 3, 10, 21, and 136 d in epididymal and retroperitoneal AT with the use of (2)H(2)O labeling. In experiment 2, dams received a control or high-fat diet from mating to 21 d after delivery. The offspring received a high-fat diet from 22 to 105 d; adiposity was measured at 2, 21, 54, and 97 d. RESULTS: The fractional proliferation rate (FPR) of cells in epididymal AT was 25.2% of cells synthesized in 5 d at 3 d of age and decreased over time (P < 0.001). Age had no effect on retroperitoneal FPR (P = 0.179). In both depots, the fractional synthesis rate (FSR) of palmitate decreased extensively from day 3 to day 10, increasing by day 21 and declining by day 136 (P < 0.001). The FSR of triglycerides decreased with age (P < 0.001). A maternal high-fat diet increased the offspring's adiposity at 2 d and 21 d (P < 0.05) but had no effect on body composition later in life. CONCLUSIONS: Adipogenesis in the guinea pig is very active during early life and was altered by a maternal high-fat diet; thus, it is an adequate model for intrauterine fat deposition. However, there were no effects of maternal diet later in life.

Fasting plasma chenodeoxycholic acid and cholic acid concentrations are inversely correlated with insulin sensitivity in adults.

BACKGROUND: Accumulating data suggest a novel role for bile acids (BAs) in modulating metabolic homeostasis. BA treatment has been shown to improve glucose tolerance and to increase energy expenditure in mice. Here, we investigated the relationship between fasting plasma BAs concentrations and metabolic parameters in humans. FINDINGS: Fasting plasma glucose, insulin and lipid profile were measured in 14 healthy volunteers, 20 patients with type 2 diabetes (T2D), and 22 non-diabetic abdominally obese subjects. Insulin sensitivity was also assessed by the determination of the glucose infusion rate (GIR) during a hyperinsulinemic-euglycemic clamp in a subgroup of patients (9 healthy and 16 T2D subjects). Energy expenditure was measured by indirect calorimetry. Plasma cholic acid (CA), chenodeoxycholic acid (CDCA) and deoxycholic acid (DCA) concentrations were analyzed by gas chromatograph-mass spectrometry. In univariable analysis, a positive association was found between HOMA-IR and plasma CDCA (ß = 0.09, p = 0.001), CA (ß = 0.03, p = 0.09) and DCA concentrations (ß = 0.07, p < 0.0001). Spearman analysis retrieved an inverse relationship between plasma CDCA (r = -0.44, p = 0.03), CA (r = -0.65, p = 0.001) and the GIR. HOMA-IR remained positively associated with CDCA (ß = 0.11, p = 0.01), CA (ß = 0.04, p = 0.01) and DCA (ß = 0.06, p = 0.007) in multivariable analysis, after adjustment for age, gender, BMI, HbA1C and plasma lipid parameters. In contrast, HbA1c, energy expenditure and plasma lipid concentrations were not correlated with plasma BAs levels in multivariable analysis. CONCLUSIONS: Both plasma CDCA, CA and DCA concentrations were negatively associated with insulin sensitivity in a wide range of subjects.

Acetogenic fibers reduce fasting glucose turnover but not peripheral insulin resistance in metabolic syndrome patients.

BACKGROUND & AIMS: The acute ingestion of an acetogenic indigestible carbohydrate (lactulose) increased acetate turnover associated with decreased lipolysis (glycerol turnover) in insulin-resistant patients. It is not known whether a decreased lipolysis by chronic ingestion of acetogenic indigestible carbohydrates or fibers improves glucose turnover and insulin sensitivity. METHODS: Twenty-one men with metabolic syndrome ingested daily standardized drinks, with or without 28 g acetogenic fibers (acacia gum and pectin), for 5 weeks in a randomized double-blind crossover controlled study design. Euglycaemic-hyperinsulinaemic (EH) clamps coupled with kinetic studies were performed in the fasting state after treatments. RESULTS: Flatulence was more frequent with fiber treatment. Body weight, lipids as well as acetate and glycerol turnovers were unchanged. Fasting endogenous glucose turnover was improved after fiber treatment (7.9 ± 1.3 µmol kg(-1) min(-1)) compared with control (8.6 ± 1.6 µmol kg(-1) min(-1), P < 0.05). But insulin sensitivity (glucose infusion rate) during the EH clamp was not different at the end of fiber and control treatments, 3.7 ± 1.8 and 3.8 ± 1.5 mg kg(-1) min(-1), respectively, nor fasting plasma glucose and insulin. CONCLUSIONS: The chronic ingestion of acacia gum and pectin fibers did not decrease lipolysis but improved fasting endogenous glucose turnover with no effect on peripheral insulin resistance in metabolic syndrome patients.

A low alpha-linolenic intake during early life increases adiposity in the adult guinea pig.

BACKGROUND: The composition of dietary fatty acids (FA) during early life may impact adult adipose tissue (AT) development. We investigated the effects of alpha-linolenic acid (ALA) intake during the suckling/weaning period on AT development and metabolic markers in the guinea pig (GP). METHODS: Newborn GP were fed a 27%-fat diet (w/w %) with high (10%-ALA group), moderate (2.4%-ALA group) or low (0.8%-ALA group) ALA content (w/w % as total FA) until they were 21 days old (d21). Then all animals were switched to a 15%-fat diet containing 2% ALA (as total FA) until 136 days of age (d136). RESULTS: ALA and docosapentaenoic acid measured in plasma triglycerides (TG) at d21 decreased with decreasing ALA intake. Total body fat mass was not different between groups at d21. Adipose tissue TG synthesis rates and proliferation rate of total adipose cells, as assessed by 2H2O labelling, were unchanged between groups at d21, while hepatic de novo lipogenesis was significantly 2-fold increased in the 0.8%-ALA group. In older GP, the 0.8%-ALA group showed a significant 15-%-increased total fat mass (d79 and d107, p < 0.01) and epididymal AT weight (d136) and tended to show higher insulinemia compared to the 10%-ALA group. In addition, proliferation rate of cells in the subcutaneous AT was higher in the 0.8%-ALA (15.2 +/- 1.3% new cells/5d) than in the 10%-ALA group (8.6 +/- 1.7% new cells/5d, p = 0.021) at d136. AT eicosanoid profiles were not associated with the increase of AT cell proliferation. CONCLUSION: A low ALA intake during early postnatal life promotes an increased adiposity in the adult GP.

Isotopomics: a top-down systems biology approach for understanding dynamic metabolism in rats using [1,2-(13)C(2)] acetate.

Isotope labeled tracers are commonly used to quantify the turnover rates of various metabolic intermediates and yield information regarding physiological regulation. Studies often only consider either one nutritional state (fasted or fed) and/or one question (e.g., measure of lipid or protein turnover). In this article, we consider a novel application combining the global approach of metabonomics with widespread stable isotope labeling as a way of being able to map metabolism in open mammalian systems, an approach we call "isotopomics". A total of 45 15-week-old male Zucker rats were administrated different amounts (from 0.5 to 8 mmol/kg) of sodium [1,2-(13)C(2)] acetate. Plasma samples taken at 1, 4, and 24 h were analyzed with (13)C nuclear magnetic resonance (NMR) and gas chromatography/mass spectrometry (GC/MS) to measure (13)C isotopic enrichment of 39 plasma metabolites across a wide range of compound classes (amino acids, short-chain fatty acids, lactate, glucose, and free fatty acids). Isotopic enrichment from 0.1-7.1 mole percent excess (MPE) for the highest dose could be reliably measured in 16 metabolites, and the kinetics of their (13)C isotopic enrichment are reported. Clustering metabolites based on (13)C kinetic curves enabled highlighting of time dependent patterns of (13)C distribution through the key metabolic pathways. These kinetic and quantitative data were reported into a biochemical map. This type of isotopomic approach for mapping dynamic metabolism in an open system has great potential for advancing our mechanistic knowledge of how different interventions and diseases can impact the metabolic response of animals and humans.

Dynamics of adipose tissue development by 2H2O labeling.

Adipose tissue development undergoes remodeling in terms of newly synthesized cells (hyperplasia) and newly synthesized lipids that accumulate in adipocytes (hypertrophy). Synthesis and/or breakdown rates of adipose cells and lipids follow a continuous and dynamic pattern, e.g., during obesity development. This chapter describes a unique in vivo method to measure the dynamics of adipose tissue growth using 2H2O labeling and mass spectrometry analyses. The approach uses 2H2O as a metabolic tracer to label the adipose tissue components such as the triglycerides (TG), the fatty acids, and the genomic DNA. Deuterium from 2H2O incorporates in the C-H bonds of glycerol moiety of TG through glyceroneogenesis as well as in palmitate moiety through de novo lipogenesis (DNL). Deuterium also incorporates into DNA through the de novo nucleoside synthesis pathway. The labeled water, 2H2O, is administrated intraperitoneally and/or orally in rodents or in humans for a defined duration and biopsies are collected at the end of the labeling period. We describe the procedure to extract, isolate, and purify the adipose components (TG-glycerol, TG-palmitate, and genomic DNA) and the derivation procedure to analyze the isotopic 2H-enrichment of these components by gas chromatography/mass spectrometry. The calculation principles are described to obtain the fractional and absolute synthesis rates of TG, of DNL, and of DNA measured in the adipose tissues. The method is nonradioactive, nonhazardous, accurate, reproducible, and very sensitive. We present recent in vivo data on the ontogeny of adipose tissue growth dynamics in young and adult obese Zucker rats compared with lean Zucker rats.

Chicory increases acetate turnover, but not propionate and butyrate peripheral turnovers in rats.

Chicory roots are rich in inulin that is degraded into SCFA in the caecum and colon. Whole-body SCFA metabolism was investigated in rats during food deprivation and postprandial states. After 22 h of food deprivation, sixteen rats received an IV injection of radioactive 14C-labelled SCFA. The volume of distribution and the fractional clearance rate of SCFA were 0.25-0.27 litres/kg and 5.4-5.9 %/min, respectively. The half-life in the first extracellular rapidly decaying compartment was between 0.9 and 1.4 min. After 22 h of food deprivation, another seventeen rats received a primed continuous IV infusion of 13C-labelled SCFA for 2 h. Isotope enrichment (13C) of SCFA was determined in peripheral arterial blood by MS. Peripheral acetate, propionate and butyrate turnover rates were 29, 4 and 0.3 micromol/kg per min respectively. Following 4 weeks of treatment with chicory root or control diets, eighteen fed rats received a primed continuous IV infusion of 13C-labelled SCFA for 2 h. Intestinal degradation of dietary chicory lowered caecal pH, enhanced caecal and colonic weights, caecal SCFA concentrations and breath H2. The diet with chicory supplementation enhanced peripheral acetate turnover by 25 % (P = 0.017) concomitant with an increase in plasma acetate concentration. There were no changes in propionate or butyrate turnovers. In conclusion, by setting up a multi-tracer approach to simultaneously assess the turnovers of acetate, propionate and butyrate it was demonstrated that a chronic chicory-rich diet significantly increases peripheral acetate turnover but not that of propionate or butyrate in rats.

Intramyocellular lipid stores increase markedly in athletes after 1.5 days lipid supplementation and are utilized during exercise in proportion to their content.

Intramyocellular lipids (IMCL) and muscle glycogen provide local energy during exercise (EX). The objective of this study was to clarify the role of high versus low IMCL levels at equal initial muscle glycogen on fuel selection during EX. After 3 h of depleting exercise, 11 endurance-trained males consumed in a crossover design a high-carbohydrate (7 g kg(-1) day(-1)) low-fat (0.5 g kg(-1) day(-1)) diet (HC) for 2.5 days or the same diet with 3 g kg(-1) day(-1) more fat provided during the last 1.5 days of diet (four meals; HCF). Respiratory exchange, thigh muscle substrate breakdown by magnetic resonance spectroscopy, and plasma FFA oxidation ([1-(13)C]palmitate) were measured during EX (3 h, 50% W (max)). Pre-EX IMCL concentrations were 55% higher after HCF. IMCL utilization during EX in HCF was threefold greater compared with HC (P < 0.001) and was correlated with aerobic power and highly correlated (P < 0.001) with initial content. Glycogen values and decrements during EX were similar. Whole-body fat oxidation (Fat(ox)) was similar overall and plasma FFA oxidation smaller (P < 0.05) during the first EX hour after HCF. Myocellular fuels contributed 8% more to whole-body energy demands after HCF (P < 0.05) due to IMCL breakdown (27% Fat(ox)). After EX, when both IMCL and glycogen concentrations were again similar across trials, a simulated 20-km time-trial showed no difference in performance between diets. In conclusion, IMCL concentrations can be increased during a glycogen loading diet by consuming additional fat for the last 1.5 days. During subsequent exercise, IMCL decrease in proportion to their initial content, partly in exchange for peripheral fatty acids.

Selective uptake of high density lipoproteins cholesteryl ester in the dog, a species lacking in cholesteryl ester transfer protein activity; An in vivo approach using stable isotopes.

Amongst the processes involved in the reverse cholesterol transport (RCT) from organs to liver, including high density lipoproteins-apolipoprotein AI (HDL-apoAI) dependent tissue uptake and cholesteryl ester transfer protein (CETP)-mediated transfers, the selective uptake of cholesteryl ester (CE) is of increasing interest through its antiatherogenic role. The purpose of this report is to develop a simple protocol allowing study of this process in an animal model with easier quantification of CE selective uptake. The dog was chosen essentially because this animal has a low CETP activity and an appropriate size to conduce a kinetic study. Tracer kinetics were performed to estimate in vivo the contributions of the pathways involved in HDL-CE turnover in dogs. Stable isotopes, 13C-acetate and D3-leucine as labeled precursors of CE and apoAI, were infused to fasting dogs. Isotopic enrichments were monitored in plasma unesterified cholesterol and in HDL-CE and apoAI by mass spectrometry. Kinetics were analyzed using compartmental modeling. Results concerned the measurement of the activity of cholesterol esterification (0.13+/-0.032 h(-1)), rate of HDL-apoAI catabolism (0.024+/-0.012 h(-1)), HDL-CE turnover (0.062+/-0.010 h(-1)) and CE selective uptake (0.038+/-0.014 h(-1)). Our results show that CE in dogs is mainly eliminated by selective uptake of HDL-CE (60% of HDL-CE turnover), unlike in other species studied by similar methods in our laboratory. This study shows that among species used to analyze cholesterol metabolism, the dog appears to be the animal in whom HDL-CE selective uptake represents the largest part of HDL-CE turnover.

Non-esterified plant sterols solubilized in low fat milks inhibit cholesterol absorption--a stable isotope double-blind crossover study.

BACKGROUND: The cholesterol absorption inhibiting properties of plant sterols in milks are unknown. The milk fat globule membrane components may enhance the absorption of cholesterol and could make plant sterols less efficient in this complex matrix. AIM OF THE STUDY: To evaluate in hypercholesterolemic men the cholesterol absorption inhibiting properties of verified properly solubilized, non-esterified plant sterols in partly vegetable oil containing milks. METHODS: The plant sterols in milk were determined to be properly solubilized, and to have effective in vitro functionality. Sixteen hypercholesterolemic adult men (initial total cholesterol 5.8-8.6 mM) then consumed milk containing sterols (1.8 g of non-esterified pure plant sterols/d) and control milk, alternatively, during two 6-day periods in a double blind cross over design. During the trial, cholesterol absorption was evaluated from the ratio of plasma isotopic enrichment of [26, 26, 26, 27, 27, 27-(2)H(6)]cholesterol from oral intake (35.6 +/- 0.2 micromol, +/- SEM) over enrichment of [23, 24, 25, 26, 27-(13)C(5)]cholesterol from intravenous injection (77.9 +/- 0.5 micromol). RESULTS: Plant sterols in low fat milks contained very few crystals > 11 microm in the presence and absence of bile salts and lysophospholipids, and inhibited cholesterol uptake in Caco-2 cell. This assured that the sterols were properly solubilized prior to the clinical trial. In the clinical study, compliance of volunteers was excellent. After tracer injections (72 h), the plasma [(2)H] and [(13)C] isotopic enrichments changed from 0.024 +/- 0.001 and 0.072 +/- 0.003 MPE (control) to 0.015 +/- 0.001 and 0.074 +/- 0.002 MPE during sterol treatment, respectively. Cholesterol absorption was reduced from 70.1 +/- 4.2 % with control to 41.1 +/- 4.0 % with milks containing plant sterol (P < 0.001). CONCLUSIONS: These results demonstrate that properly solubilized non-esterified plant sterols in milks significantly inhibit cholesterol absorption in mildly hypercholesterolemic men.