54 results found
Frampton J, Murphy K, Frost G, et al., 2021, Higher dietary fibre intake is associated with increased skeletal muscle mass and strength in adults aged 40 years and older, Journal of Cachexia, Sarcopenia and Muscle, ISSN: 2190-6009
BackgroundSkeletal muscle mass begins to decline from 40 years of age. Limited data suggest that dietary fibre may modify lean body mass, of which, skeletal muscle is the largest and most malleable component. We investigated the relationship between dietary fibre intake, skeletal muscle mass, and associated metabolic and functional parameters in adults aged 40 years and older. MethodsWe analysed cross-sectional data from the US National Health and Nutrition Examination Survey between 2011 and 2018 from adults aged 40 years and older. Covariate-adjusted multiple linear regression analyses were used to evaluate the association between dietary fibre intake and body mass components (body mass, BMI, total lean mass, appendicular lean mass, bone mineral content, total fat, trunk fat; n = 6454), glucose homeostasis (fasting glucose, fasting insulin, HOMA2-IR; n = 5032), and skeletal muscle strength (combined grip strength; n = 5326). Body mass components and skeletal muscle strength were expressed relative to body mass (per kg of body mass [BM]). ResultsHigher intakes of dietary fibre were significantly associated with increased relative total lean mass (β: 0.69 g/kg BM; 95% CI, 0.48 to 0.89 g/kg BM; P<0.001), relative appendicular lean mass (β: 0.34 g/kg BM; 95% CI, 0.23 to 0.45 g/kg BM; P<0.001), relative bone mineral content (β: 0.05 g/kg BM; 95% CI, 0.02 to 0.07 g/kg BM; P<0.001), and relative combined grip strength (β: 0.002 kg/kg BM; 95% CI, 0.001 to 0.003 kg/kg BM; P<0.001).Conversely, higher dietary fibre intakes were significantly associated with a lower body mass (β: -0.20; 95% CI, -0.28 to -0.11 kg; P<0.001), BMI (β: -0.08 kg/m2; 95%CI, -0.10 to -0.05 kg/m2), relative total fat (β: -0.68 g/kg BM; 95% CI, -0.89 to -0.47 g/kg BM; P<0.001), relative trunk fat (β: -0.48 g/kg BM; 95%CI, -0.63 to -0.33 g/kg; P<0.001), fasting glucose (β: -0.01 mmol/L; 95% CI, -0.02 to -0.00 mmol/L; P=0.017), fasting ins
Frampton J, Cobbold B, Nozdrin M, et al., 2021, The effect of a single bout of continuous aerobic exercise on glucose, insulin and glucagon concentrations compared to resting conditions in healthy adults: a systematic review, meta-analysis and meta-regression, Sports Medicine, Vol: 51, Pages: 1949-1966, ISSN: 0112-1642
Background:Elevated glucose and insulin levels are major risk factors in the development of cardiometabolic disease. Aerobic exercise is widely recommended to improve glycaemic control, yet its acute effect on glycaemia and glucoregulatory hormones has not been systematically reviewed and analysed in healthy adults.Objective:To determine the effect of a single bout of continuous aerobic exercise on circulating glucose, insulin, and glucagon concentrations in healthy adults.Methods:CENTRAL, CINAHL, Embase, Global Health, HMIC, Medline, PubMed, PsycINFO, ScienceDirect, Scopus and Web of Science databases were searched from inception to May 2020. Papers were included if they reported a randomised, crossover study measuring glucose and/or insulin and/or glucagon concentrations before and immediately after a single bout of continuous aerobic exercise (≥ 30 min) compared to a time-matched, resting control arm in healthy adults. The risk of bias and quality of evidence were assessed using the Cochrane Risk of Bias Tool and GRADE approach, respectively. Random-effects meta-analyses were performed for glucose, insulin, and glucagon. Sub-group meta-analyses and meta-regression were performed for categorical (metabolic state [postprandial or fasted], exercise mode [cycle ergometer or treadmill]) and continuous (age, body mass index, % males, maximal aerobic capacity, exercise duration, exercise intensity) covariates, respectively.Results42 papers (51 studies) were considered eligible: glucose (45 studies, 391 participants), insulin (38 studies, 377 participants) and glucagon (5 studies, 47 participants). Acute aerobic exercise had no significant effect on glucose concentrations (mean difference: − 0.05 mmol/L; 95% CI, − 0.22 to 0.13 mmol/L; P = 0.589; I2: 91.08%, large heterogeneity; moderate-quality evidence). Acute aerobic exercise significantly decreased insulin concentrations (mean difference: − 18.07 pmol/L; 95% CI, − 30.47
Wu Y, Posma JM, Holmes E, et al., 2021, Odd chain fatty acids are not robust biomarkers for dietary intake of fiber, Molecular Nutrition and Food Research, ISSN: 1613-4125
Prior investigation has suggested a positive association between increased colonic propionate production and circulating odd-chain fatty acids [(OCFAs; pentadecanoic acid (C15:0), heptadecanoic acid (C17:0)]. As the major source of propionate in humans is the microbial fermentation of dietary fiber, OCFAs have been proposed as candidate biomarkers of dietary fiber. The objective of this study is to critically assess the plausibility, robustness, reliability, dose-response, time-response aspects of OCFAs as potential biomarkers of fermentable fibers in two independent studies using a validated analytical method. OCFAs were first assessed in a fiber supplementation study, where 21 participants received 10g dietary fiber supplementation for 7 days with blood samples collected on the final day at a 420 minute study visit. OCFAs were then assessed in a highly controlled inpatient setting, which 19 participants consumed a high fiber (45.1g/day) and a low fiber diet (13.6g/day) for 4 days. Collectively in both studies, dietary intakes of fiber as fiber supplementations or having consumed a high fiber diet did not increase circulating levels of OCFAs. The dose and temporal relations were not observed. Current study has generated new insight on the utility of OCFAs as fiber biomarkers and highlighted the importance of critical assessment of candidate dietary biomarkers before application.
Wallis GA, Chambers ES, 2021, UK Nutrition Research Partnership (NRP) workshop: Improving our understanding of the metabolic interplay between nutrition and physical activity (IN-PACT), NUTRITION BULLETIN, ISSN: 1471-9827
Brignardello J, Fountana S, Posma JM, et al., 2021, Characterization of diet-dependent temporal changes in circulating short-chain fatty acid concentrations: A randomized crossover dietary trial, The American Journal of Clinical Nutrition, ISSN: 0002-9165
Background: Production of Short-chain fatty acids (SCFAs) from food is a complex and dynamic saccharolytic fermentation process mediated by both human and gut microbial factors. SCFA production and knowledge of the relationship between SCFA profiles and dietary patterns is lacking. Objective: Temporal changes in SCFA levels in response to two contrasting diets were investigated using a novel GC-MS method.Design: Samples were obtained from a randomized, controlled, crossover trial designed to characterize the metabolic response to four diets. Participants (n=19) undertook these diets during an inpatient stay (of 72-h). Serum samples were collected 2-h after breakfast (AB), lunch (AL) and dinner (AD) on day 3 and a fasting sample (FA) was obtained on day 4. 24-h urine samples were collected on day 3. In this sub-study, samples from the two extreme diets representing a diet with high adherence to WHO healthy eating recommendations and a typical Western diet were analyzed using a bespoke GC-MS method developed to detect and quantify 10 SCFAs and precursors in serum and urine samples. Results: Considerable inter-individual variation in serum SCFA concentrations was observed across all time points and temporal fluctuations were observed for both diets. Although the sample collection timing exerted a greater magnitude of effect on circulating SCFA concentrations, the unhealthy diet was associated with a lower concentration of acetic acid (FA: coefficient=-17.0; standard error (SE)=5.8; p-trend=0.00615), 2-methylbutyric acid (AL: coefficient=-0.1; SE=0.028; p-trend=4.13x10-4 and AD: coefficient =-0.1; SE:=0.028; p-trend=2.28x10-3) and 2-hydroxybutyric acid (FA: coefficient=-15.8; standard error=5.11; p-trend: 4.09x10-3). In contrast lactic acid was significantly higher in the unhealthy diet (AL: coefficient=750.2; standard error=315.2; p-trend=0.024 and AD: coefficient=1219.3; standard error=322.6; p-trend: 8.28x10-4). Conclusion: The GC-MS method allowed robust mapping of
Petropoulou K, Salt LJ, Edwards CH, et al., 2020, A natural mutation in Pisum sativum L. (pea) alters starch assembly and improves glucose homeostasis in humans, Nature Food
Willis ND, Lloyd AJ, Xie L, et al., 2020, Design and characterisation of a randomized food intervention that mimics exposure to a typical UK diet to provide urine samples for identification and validation of metabolite biomarkers of food intake, Frontiers in Nutrition, Vol: 7, Pages: 1-16, ISSN: 2296-861X
Poor dietary choices are major risk factors for obesity and non-communicable diseases, which places an increasing burden on healthcare systems worldwide. To monitor the effectiveness of healthy eating guidelines and strategies, there is a need for objective measures of dietary intake in community settings. Metabolites derived from specific foods present in urine samples can provide objective biomarkers of food intake (BFIs). Whilst the majority of biomarker discovery/validation studies have investigated potential biomarkers for single foods only, this study considered the whole diet by using menus that delivered a wide range of foods in meals that emulated conventional UK eating patterns. Fifty-one healthy participants (range 19–77 years; 57% female) followed a uniquely designed, randomized controlled dietary intervention, and provided spot urine samples suitable for discovery of BFIs within a real-world context. Free-living participants prepared and consumed all foods and drinks in their own homes and were asked to follow the protocols for meal consumption and home urine sample collection. This study also assessed the robustness, and impact on data quality, of a minimally invasive urine collection protocol. Overall the study design was well-accepted by participants and concluded successfully without any drop outs. Compliance for urine collection, adherence to menu plans, and observance of recommended meal timings, was shown to be very high. Metabolome analysis using mass spectrometry coupled with data mining demonstrated that the study protocol was well-suited for BFI discovery and validation. Novel, putative biomarkers for an extended range of foods were identified including legumes, curry, strongly-heated products, and artificially sweetened, low calorie beverages. In conclusion, aspects of this study design would help to overcome several current challenges in the development of BFI technology. One specific attribute was the examination of BFI generalizabil
Frampton J, Murphy KG, Frost G, et al., 2020, Short-chain fatty acids as potential regulators of skeletal muscle metabolism and function, Nature Metabolism, Vol: 2, Pages: 840-848, ISSN: 2522-5812
A key metabolic activity of the gut microbiota is the fermentation of non-digestible carbohydrate, which generates short-chain fatty acids (SCFAs) as the principal end products. SCFAs are absorbed from the gut lumen and modulate host metabolic responses at different organ sites. Evidence suggests that these organ sites include skeletal muscle, the largest organ in humans, which plays a pivotal role in whole-body energy metabolism. In this Review, we evaluate the evidence indicating that SCFAs mediate metabolic cross-talk between the gut microbiota and skeletal muscle. We discuss the effects of three primary SCFAs (acetate, propionate and butyrate) on lipid, carbohydrate and protein metabolism in skeletal muscle, and we consider the potential mechanisms involved. Furthermore, we highlight the emerging roles of these gut-derived metabolites in skeletal muscle function and exercise capacity, present limitations in current knowledge and provide suggestions for future work.
Cherta-Murillo A, Lett AM, Frampton J, et al., 2020, Effects of mycoprotein on glycaemic control and energy intake in humans: a systematic review, British Journal of Nutrition, Vol: 123, Pages: 1321-1332, ISSN: 0007-1145
Mycoprotein is a food high in both dietary fibre and non-animal derived protein. Global mycoprotein consumption is increasing although its effect on human health has not yet been systematically reviewed. This study aims to systematically review the effects of mycoprotein on glycaemic control and energy intake in humans. A literature search of randomised controlled trials was performed in Pubmed, EMBASE, Web of Science, Google Scholar and hand search. A total of 21 studies were identified of which only 5 studies, totalling 122 participants, met the inclusion criteria. All 5 studies were acute studies of which 1 reported outcomes on glycaemia and insulinaemia, 2 reported on energy intake and 2 reported on all of these outcomes. Data were extracted and risk-of-bias assessment was then conducted. The results did not show a clear effect of acute mycoprotein on blood glucose levels but it showed a decrease in insulin levels. Acute mycoprotein intake also showed to decrease energy intake at an <jats:italic>ad libitum</jats:italic> meal and post-24h in healthy lean, overweight and obese humans. In conclusion, the acute ingestion of mycoprotein reduces energy intake and insulinaemia whereas its impact on glycaemia is currently unclear. However, evidence comes from a very limited number of heterogeneous studies. Further well-controlled studies are needed to elucidate the short- and long-term effects of mycoprotein intake on glycaemic control and energy intake, as well as the mechanisms underpinning these effects.
Garcia Perez I, Posma JM, Chambers E, et al., 2020, Dietary metabotype modelling predicts individual responses to dietary interventions, Nature Food, Vol: 1, Pages: 355-364, ISSN: 2662-1355
Habitual consumption of poor quality diets is linked directly to risk factors for many non-communicable disease. This has resulted in the vast majority of countries globally and the World Health Organisation developing policies for healthy eating to reduce the prevalence of non communicable disease in the population. However, there is mounting evidence of variability in individual metabolic responses to any dietary intervention. We have developed a method for applying a pipeline for understanding inter-individual differences in response to diet, based on coupling data from highly-controlled dietary studies with deep metabolic phenotyping. In this feasibility study, we create an individual Dietary Metabotype Score (DMS) that embodies inter-individual variability in dietary response and captures consequent dynamic changes in concentrations of urinary metabolites. We find an inverse relationship between the DMS and blood glucose concentration. There is also a relationship between the DMS and urinary metabolic energy loss. Furthermore we employ a metabolic entropy approach to visualize individual and collective responses to dietary. Potentially, the DMS offers a method to target and to enhance dietary response at an individual level therefore reducing burden of non communicable diseases at a population level.
Malkova D, Polyviou T, Rizou E, et al., 2020, Moderate intensity exercise training combined with inulin-propionate ester supplementation increases whole body resting fat oxidation in overweight women, Metabolism: clinical and experimental, Vol: 104, ISSN: 0026-0495
BACKGROUND: Our previous work has shown that oral supplementation with inulin propionate ester (IPE) reduces intra-abdominal fat and prevents weight gain and that oral propionate intake enhances resting fat oxidation. The effects of IPE combined with exercise training on energy substrate utilisation are unknown. The aim of this study was to investigate the impact of 4-weeks IPE supplementation, in combination with a moderate intensity exercise training programme, on whole body fat oxidation and on plasma GLP-1 and PYY. METHODS: Twenty overweight healthy women participated in randomised parallel study and underwent 4 weeks of supervised exercise training either with IPE (EX/IPE group) or Placebo (EX/Placebo group) supplementation. Before and after the intervention participants conducted an experimental trial, which involved collection of expired gas and blood samples in the fasted state and during 7 h of the postprandial state. RESULTS: Within groups, the EX/IPE group significantly enhanced the amount of fat (Pre, 24.1 ± 1.2 g; Post, 35.9 ± 4.0 g, P < 0.05) oxidised and reduced CHO (Pre, 77.8 ± 6.0 g; Post, 57.8 ± 7.7 g, P < 0.05) oxidised, reduced body weight (Pre, 77.3 ± 4.2 kg; Post, 76.6 ± 4.1 kg, P < 0.05) and body fat mass (Pre, 37.7 ± 1.9%; Post, 36.9 ± 1.9%, P < 0.05). In EX/Placebo group, changes in amount of fat (Pre, 36.8 ± 3.9 g; Post, 37.0 ± 4.0 g) and CHO (Pre, 62.7 ± 6.5 g; Post, 61.5 ± 7.4 g) oxidised, body weight (Pre, 84.2 ± 4.3 kg; Post, 83.6 ± 4.3 kg) and body fat mass (Pre, 40.1 ± 1.9%; Post, 38.7 ± 1.5%) were not significant (P > 0.05). Comparing between groups, changes in the amount of fat oxidised were significantly (P < 0.05) different and a trend for difference was observed for amount of CHO oxidised (P = 0.06) and RER (P = 0.06). The interventions had no impact on fasting or postprandial plasma concentrations of
Corrado M, Cherta-Murillo A, Chambers ES, et al., 2020, Effect of semolina pudding prepared from starch branching enzyme IIa and b mutant wheat on glycaemic response in vitro and in vivo: a randomised controlled pilot study, FOOD & FUNCTION, Vol: 11, Pages: 617-627, ISSN: 2042-6496
Wilson T, Garcia-Perez I, Posma JM, et al., 2019, Spot and cumulative urine samples are suitable replacements for 24-hour urine collections for objective measures of dietary exposure in adults using metabolite biomarkers, Journal of Nutrition, Vol: 149, Pages: 1692-1700, ISSN: 0022-3166
BACKGROUND: Measurement of multiple food intake exposure biomarkers in urine may offer an objective method for monitoring diet. The potential of spot and cumulative urine samples that have reduced burden on participants as replacements for 24-h urine collections has not been evaluated. OBJECTIVE: The aim of this study was to determine the utility of spot and cumulative urine samples for classifying the metabolic profiles of people according to dietary intake when compared with 24-h urine collections in a controlled dietary intervention study. METHODS: Nineteen healthy individuals (10 male, 9 female, aged 21-65 y, BMI 20-35 kg/m2) each consumed 4 distinctly different diets, each for 1 wk. Spot urine samples were collected ∼2 h post meals on 3 intervention days/wk. Cumulative urine samples were collected daily over 3 separate temporal periods. A 24-h urine collection was created by combining the 3 cumulative urine samples. Urine samples were analyzed with metabolite fingerprinting by both high-resolution flow infusion electrospray mass spectrometry (FIE-HRMS) and proton nuclear magnetic resonance spectroscopy (1H-NMR). Concentrations of dietary intake biomarkers were measured with liquid chromatography triple quadrupole mass spectrometry and by integration of 1H-NMR data. RESULTS: Cross-validation modeling with 1H-NMR and FIE-HRMS data demonstrated the power of spot and cumulative urine samples in predicting dietary patterns in 24-h urine collections. Particularly, there was no significant loss of information when post-dinner (PD) spot or overnight cumulative samples were substituted for 24-h urine collections (classification accuracies of 0.891 and 0.938, respectively). Quantitative analysis of urine samples also demonstrated the relation between PD spot samples and 24-h urines for dietary exposure biomarkers. CONCLUSIONS: We conclude that PD spot urine samples are suitable replacements for 24-h urine collections. Alternatively, cumulative samples collected overn
Gibson R, Eriksen R, Chambers E, et al., 2019, Intakes and food sources of dietary fibre and their associations with measures of body composition and inflammation in UK adults: Cross-sectional analysis of the Airwave Health Monitoring Study, Nutrients, Vol: 11, ISSN: 2072-6643
The purpose of this study was to investigate the associations between intakes of fibre from the main food sources of fibre in the UK diet with body mass index (BMI), percentage body fat (%BF), waist circumference (WC) and C-reactive protein (CRP). Participants enrolled in the Airwave Health Monitoring Study (2007–2012) with 7-day food records (n = 6898; 61% men) were included for cross-sectional analyses. General linear models evaluated associations across fifths of fibre intakes (total, vegetable, fruit, potato, whole grain and non-whole grain cereal) with BMI, %BF, WC and CRP. Fully adjusted analyses showed inverse linear trends across fifths of total fibre and fibre from fruit with all outcome measures (ptrend < 0.0001). Vegetable fibre intake showed an inverse association with WC (ptrend 0.0156) and CRP (ptrend 0.0005). Fibre from whole grain sources showed an inverse association with BMI (ptrend 0.0002), %BF (ptrend 0.0007) and WC (ptrend 0.0004). Non-whole grain cereal fibre showed an inverse association with BMI (Ptrend 0.0095). Direct associations observed between potato fibre intake and measures of body composition and inflammation were attenuated in fully adjusted analyses controlling for fried potato intake. Higher fibre intake has a beneficial association on body composition, however, there are differential associations based on the food source.
Chambers E, Byrne C, Rugyendo A, et al., 2019, The effects of dietary supplementation with inulin and inulin-propionate ester on hepatic steatosis in adults with non-alcoholic fatty liver disease, Diabetes, Obesity and Metabolism, Vol: 21, Pages: 372-376, ISSN: 1462-8902
The short chain fatty acid (SCFA) propionate, produced through fermentation of dietary fibre by the gut microbiota, has been shown to alter hepatic metabolic processes that reduce lipid storage. We aimed to investigate the impact of raising colonic propionate production on hepatic steatosis in adults with non‐alcoholic fatty liver disease (NAFLD). Eighteen adults were randomised to receive 20g/day of an inulin‐propionate ester (IPE), designed to deliver propionate to the colon, or an inulin‐control for 42‐days in a parallel design. The change in intrahepatocellular lipid (IHCL) following the supplementation period was not different between groups (P=0.082), however IHCL significantly increased within the inulin‐control group (20.9±2.9 to 26.8±3.9%; P=0.012; n=9), which was not observed within the IPE group (22.6±6.9 to 23.5±6.8%; P=0.635; n=9). The predominant SCFA from colonic fermentation of inulin is acetate, which in a background of NAFLD and a hepatic metabolic profile that promotes fat accretion, may provide surplus lipogenic substrate to the liver. The increased colonic delivery of propionate from IPE appears to attenuate this acetate‐mediated increase in IHCL.
Sukkar A, Lett A, Frost G, et al., 2019, Regulation of energy expenditure and substrate oxidation by short chain fatty acids, Journal of Endocrinology, Vol: 242, Pages: R1-R8, ISSN: 1479-6805
Short-chain fatty acids (SCFAs) are metabolites produced from the fermentation of dietary fibre by the gut microbiota. High-fibre diets have been associated with lower weight gain and a number of reports have therefore investigated if these positive effects of a dietary fibre on body weight can be replicated through the direct administration of SCFAs. Many of these studies have reported that SCFAs can prevent or attenuate long-term body weight gain by increasing energy expenditure through increased lipid oxidation. The aim of the present review is to therefore evaluate the current evidence for an effect of SCFAs on whole-body energy expenditure and to assess the potential underlying mechanisms. The available data highlights that SCFAs can exert multiple effects at various organ and tissue sites that would cumulatively raise energy expenditure via a promotion of lipid oxidation. In conclusion, the present review proposes that dietary interventions and other therapies that augment gut-derived SCFAs and systemic availability may present an effective strategy to improve long-term energy balance and body weight management.
Chambers E, Byrne C, Morrison D, et al., 2019, Dietary supplementation with inulin-propionate ester or inulin improves insulin sensitivity in adults with overweight and obesity with distinct effects on the gut microbiota, plasma metabolome and systemic inflammatory responses: a randomised cross-over trial, Gut, Vol: 68, Pages: 1430-1438, ISSN: 0017-5749
Objective: To investigate the underlying mechanisms behind changes in glucose homeostasis with delivery of propionate to the human colon by comprehensive and coordinated analysis of gut bacterial composition, plasma metabolome and immune responses.Design: Twelve non-diabetic adults with overweight and obesity received 20g/day of inulin-propionate ester (IPE), designed to selectively deliver propionate to the colon, a high-fermentable fibre control (inulin) and a low-fermentable fibre control (cellulose) in a randomised, double-blind, placebo controlled, crossover design. Outcome measurements of metabolic responses, inflammatory markers and gut bacterial composition were analysed at the end of each 42-day supplementation period.Results: Both IPE and inulin supplementation improved insulin resistance compared to cellulose supplementation, measured by homeostatic model assessment (HOMA) 2 (Mean±SEM 1.23±0.17 IPE vs. 1.59±0.17 cellulose, P=0.001; 1.17±0.15 inulin vs. 1.59±0.17 cellulose, P=0.009), with no differences between IPE and inulin (P=0.272). Fasting insulin was only associated positively with plasma tyrosine and negatively with plasma glycine following inulin supplementation. IPE supplementation decreased pro-inflammatory IL-8 levels compared to cellulose, whilst inulin had no impact on the systemic inflammatory markers studied. Inulin promoted changes in gut bacterial populations at the class level (increased Actinobacteria and decreased Clostridia) and order level (decreased Clostridales) compared to cellulose, with small differences at the species level observed between IPE and cellulose. Conclusion: These data demonstrate a distinctive physiological impact of raising colonic propionate delivery in humans, as improvements in insulin sensitivity promoted by IPE and inulin were accompanied with different effects on the plasma metabolome, gut bacterial populations and markers of systemic inflammation.
Lloyd AJ, Willis ND, Wilson T, et al., 2019, Developing a food exposure and urine sampling strategy for dietary exposure biomarker validation in free-living individuals, Molecular Nutrition and Food Research, Vol: 63, Pages: 1-9, ISSN: 1613-4125
SCOPE: Dietary choices modulate the risk of chronic diseases and improving diet is a central component of public health strategies. Food-derived metabolites present in urine could provide objective biomarkers of dietary exposure. To assist biomarker validation we aimed to develop a food intervention strategy mimicking a typical annual diet over a short period of time and assessed urine sampling protocols potentially suitable for future deployment of biomarker technology in free-living populations. METHODS AND RESULTS: Six different menu plans representing comprehensively a typical UK annual diet that were split into two dietary experimental periods. Free-living adult participants (n = 15 and n = 36, respectively) were provided with all their food, as a series of menu plans, over a period of 3 consecutive days. Multiple spot urine samples were collected and stored at home. CONCLUSION: We established a successful food exposure strategy following a conventional UK eating pattern, which was suitable for biomarker validation in free-living individuals. The urine sampling procedure was acceptable for volunteers and delivered samples suitable for biomarker quantification. Our study design provides scope for validation of existing biomarker candidates and potentially for discovery of new biomarker-leads and should help inform the future deployment of biomarker technology for habitual dietary exposure measurement.
Chambers E, 2019, Gut-derived short chain fatty acids: A friend or foe for hepatic lipid metabolism?, Nutrition Bulletin, Vol: 44, Pages: 154-159, ISSN: 1467-3010
This article describes how a British Nutrition Foundation Drummond Pump Priming Award was used to develop in vivo proof of concept for increasing colonic propionate as a therapeutic strategy to reduce liver fat in adults with non‐alcoholic fatty disease (NAFLD). An overview of how the gut‐derived short‐chain fatty acids propionate and acetate are taken up and metabolised by the liver is provided, as well as a summary of how acetate may have contrasting effects on hepatic lipid content depending on the metabolic health of the individual. Finally, the article proposes that raising colonic propionate production could interfere with hepatic acetate metabolism and have positive effects on liver fat accumulation in individuals with NAFLD.
Lloyd AJ, Willis ND, Wilson T, et al., 2019, Addressing the pitfalls when designing intervention studies to discover and validate biomarkers of habitual dietary intake, Metabolomics, Vol: 15, ISSN: 1573-3882
IntroductionDietary exposure monitoring within populations is reliant on self-reported measures such as Food Frequency Questionnaires and diet diaries. These methods often contain inaccurate information due to participant misreporting, non-compliance and bias. Urinary metabolites derived from individual foods could provide additional objective indicators of dietary exposure. For biomarker approaches to have utility it is essential that they cover a wide-range of commonly consumed foods and the methodology works in a real-world environment.ObjectivesTo test that the methodology works in a real-world environment and to consider the impact of the major sources of likely variance; particularly complex meals, different food formulations, processing and cooking methods, as well as the dynamics of biomarker duration in the body.MethodsWe designed and tested a dietary exposure biomarker discovery and validation strategy based on a food intervention study involving free-living individuals preparing meals and collecting urine samples at home. Two experimental periods were built around three consecutive day menu plans where all foods and drinks were provided (n = 15 and n = 36).ResultsThe experimental design was validated by confirming known consumption biomarkers in urinary samples after the first menu plan. We tested biomarker performance with different food formulations and processing methods involving meat, wholegrain, fruits and vegetables.ConclusionIt was demonstrated that spot urine samples, together with robust dietary biomarkers, despite major sources of variance, could be used successfully for dietary exposure monitoring in large epidemiological studies.
Byrne C, Chambers E, Brignardello J, et al., 2019, Effects of inulin propionate ester incorporated into palatable food products on appetite and resting energy expenditure: a randomised crossover study, Nutrients, Vol: 11, ISSN: 2072-6643
Supplementation with inulin-propionate ester (IPE), which delivers propionate to the colon, suppresses ad libitum energy intake and stimulates the release of satiety hormones acutely in humans, and prevents weight gain. In order to determine whether IPE remains effective when incorporated into food products (FP), IPE needs to be added to a widely accepted food system. A bread roll and fruit smoothie were produced. Twenty-one healthy overweight and obese humans participated. Participants attended an acclimatisation visit and a control visit where they consumed un-supplemented food products (FP). Participants then consumed supplemented-FP, containing 10 g/d inulin or IPE for six days followed by a post-supplementation visit in a randomised crossover design. On study visits, supplemented-FP were consumed for the seventh time and ad libitum energy intake was assessed 420 min later. Blood samples were collected to assess hormones and metabolites. Resting energy expenditure (REE) was measured using indirect calorimetry. Taste and appearance ratings were similar between FP. Ad libitum energy intake was significantly different between treatments, due to a decreased intake following IPE-FP. These observations were not related to changes in blood hormones and metabolites. There was an increase in REE following IPE-FP. However, this effect was lost after correcting for changes in fat free mass. Our results suggest that IPE suppresses appetite and may alter REE following its incorporation into palatable food products.
Byrne C, Blunt D, Burn J, et al., 2019, A study protocol for a randomised crossover study evaluating the effect of diets differing in carbohydrate quality on ileal content and appetite regulation in healthy humans, F1000Research, Vol: 8, ISSN: 2046-1402
Introduction: A major component of the digesta reaching the colon from the distal ileum is carbohydrate. This carbohydrate is subject to microbial fermentation and can radically change bacterial populations in the colon and the metabolites they produce, particularly short-chain fatty acids (SCFA). However, very little is currently known about the forms and levels of carbohydrate in the ileum and the composition of the ileal microbiota in humans. Most of our current understanding of carbohydrate that is not absorbed by the small intestine comes from ileostomy models, which may not reflect the physiology of an intact gastrointestinal tract. Methods: We will investigate how ileal content changes depending on diet using a randomised crossover study in healthy humans. Participants will be inpatients at the research facility for three separate 4-day visits. During each visit, participants will consume one of three diets, which differ in carbohydrate quality: 1) low-fibre refined diet; 2) high-fibre diet with intact cellular structures; 3) high-fibre diet where the cellular structures have been disrupted (e.g. milling, blending). On day 1, a nasoenteric tube will be placed into the distal ileum and its position confirmed under fluoroscopy. Ileal samples will be collected via the nasoenteric tube and metabolically profiled, which will determine the amount and type of carbohydrate present, and the composition of the ileal microbiota will be measured. Blood samples will be collected to assess circulating hormones and metabolites. Stool samples will be collected to assess faecal microbiota composition. Subjective appetite measures will be collected using visual analogue scales. Breath hydrogen will be measured in real-time as a marker of intestinal fermentation. Finally, an in vitro continuous fermentation model will be inoculated with ileal fluid in order to understand the shift in microbial composition and SCFA produced in the colon following the different diets. Registratio
Chambers ES, Byrne CS, Frost G, 2019, Carbohydrate and human health: is it all about quality?, LANCET, Vol: 393, Pages: 384-386, ISSN: 0140-6736
Chambers ES, Preston T, Frost G, et al., 2018, Role of Gut Microbiota-Generated Short-Chain Fatty Acids in Metabolic and Cardiovascular Health., Curr Nutr Rep, Vol: 7, Pages: 198-206
PURPOSE OF THIS REVIEW: This review assesses the latest evidence linking short-chain fatty acids (SCFA) with host metabolic health and cardiovascular disease (CVD) risk and presents the latest evidence on possible biological mechanisms. RECENT FINDINGS: SCFA have a range of effects locally in the gut and at both splanchnic and peripheral tissues which together appear to induce improved metabolic regulation and have direct and indirect effects on markers of CVD risk. SCFA produced primarily from the microbial fermentation of dietary fibre appear to be key mediators of the beneficial effects elicited by the gut microbiome. Not only does dietary fibre fermentation regulate microbial activity in the gut, SCFA also directly modulate host health through a range of tissue-specific mechanisms related to gut barrier function, glucose homeostasis, immunomodulation, appetite regulation and obesity. With the increasing burden of obesity worldwide, the role for gut microbiota-generated SCFA in protecting against the effects of energy dense diets offers an intriguing new avenue for regulating metabolic health and CVD risk.
Chambers E, Frost G, Byrne C, et al., 2017, Acute oral sodium propionate supplementation raises resting energy expenditure and lipid oxidation in fasted humans, Diabetes, Obesity and Metabolism, Vol: 20, Pages: 1034-1039, ISSN: 1462-8902
Short‐chain fatty acids (SCFAs), produced from fermentation of dietary fibre by the gut microbiota, have been suggested to modulate energy metabolism. Previous work using rodent models has demonstrated that oral supplementation of the SCFA propionate raises resting energy expenditure (REE) by promoting lipid oxidation. The objective of the present study was to investigate the effects of oral sodium propionate on REE and substrate metabolism in humans. Eighteen healthy volunteers (9 women and 9 men; age 25 ± 1 years; body mass index 24.1 ± 1.2 kg/m2) completed 2 study visits following an overnight fast. Tablets containing a total of 6845 mg sodium propionate or 4164 mg sodium chloride were provided over the 180‐minute study period in random order. REE and substrate oxidation were assessed by indirect calorimetry. Oral sodium propionate administration increased REE (0.045 ± 0.020 kcal/min; P = .036); this was accompanied by elevated rates of whole‐body lipid oxidation (0.012 ± 0.006 g/min; P = .048) and was independent of changes in glucose and insulin concentrations. Future studies are warranted to determine whether the acute effects of oral sodium propionate on REE translate into positive improvements in long‐term energy balance in humans.
Garcia Perez I, Posma JM, Gibson R, et al., 2017, Objective assessment of dietary patterns using metabolic phenotyping: a randomized, controlled, crossover trial, The Lancet Diabetes & Endocrinology, Vol: 5, Pages: 184-195, ISSN: 2213-8587
Background: The burden of non-communicable diseases, such as obesity, diabetes, coronary heart disease and cancer, can be reduced by the consumption of healthy diets. Accurate monitoring of changes in dietary patterns in response to food policy implementation is challenging. Metabolic profiling allows simultaneous measurement of hundreds of metabolites in urine, many of them influenced by food intake. We aim to classify people according to dietary behaviour and enhance dietary reporting using metabolic profiling of urine.Methods: To develop metabolite models from 19 healthy volunteers who attended a clinical research unit for four day periods on four occasions. We used the World Health Organisation’s healthy eating guidelines (increase fruits, vegetables, wholegrains, dietary fibre and decrease fats, sugars, and salt) to develop four dietary interventions lasting for four days each that ranged from a diet associated with a low to high risk of developing non-communicable disease. Urine samples were measured by 1H-NMR spectroscopy. This study is registered as an International Standard Randomized Controlled Trial, number ISRCTN 43087333. INTERMAP U.K. (n=225) and a healthy-eating Danish cohort (n=66) were used as free-living validation datasets.Findings: There was clear separation between the urinary metabolite profiles of the four diets. We also demonstrated significant stepwise differences in metabolite levels between the lowest and highest metabolic risk diets and developed metabolite models for each diet. Application of the derived metabolite models to independent cohorts confirmed the association between urinary metabolic and dietary profiles in INTERMAP (P<0•001) and the Danish cohort (P<0•001).Interpretation: Urinary metabolite models, developed in a highly controlled environment, can classify groups of free-living people into consumers of dietary profiles associated with lower or higher non-communicable disease risk based on multivariate m
Lloyd AJ, Zubair H, Willis ND, et al., 2016, Quantification of dietary biomarkers in spot urine samples reflects the intake of foods of UK high public health importance, Publisher: Cambridge University Press (CUP), Pages: E248-E248, ISSN: 0029-6651
An understanding of causal relations between diet and health is hindered by the lack of robust biological markers of food exposure (1).The rapid development of metabolomics technology offers opportunity for the identification of urine biomarkers for the intake of arange of foods of high public health importance (2), (3). Using high mass resolution mass spectrometry and machine learning data analysis,we have discovered potential urinary biomarkers in controlled clinical studies with a range of analytical techniques (2). To haveutility for population monitoring, we aim to validate biomarker performance in free-living individuals using urine samples collected inthe home with a minimal impact on normal daily activities.Two complementary multiple reaction monitoring (MRM) routines using triple quadrupole mass spectrometry (QQQ-MS) havebeen developed to quantify concurrently dietary exposure biomarkers of more than 20 foods of high public health importance inthe UK. MRM quantification of metabolite levels in spot urines collected either before bed time or a first morning void identifieda sub-set of potential biomarkers that demonstrated robust linkage with reported dietary intake (examples in Table 1). Figure 1demonstrates the ability of selected biomarkers to report exposure in relation to muscle meat intake from lunch time to bedtime(Beefburger; 106gm, Chicken breast; 130gm; Processed Ham; 40·5 gm) in 6 free-living individuals. Anserine was strongly, and specifically,associated with poultry intake, whilst the urinary outputs of 3-methyl histidine and carnosine reflect striated muscle intake,with levels substantially reduced when meals contain lower quality, and processed, meats with reduced levels of striated musclecontent.
Petropoulou K, Chambers ES, Morrison DJ, et al., 2016, Identifying crop variants with high resistant starch content to maintain healthy glucose homeostasis, Nutrition Bulletin, Vol: 41, Pages: 372-377, ISSN: 1467-3010
Identifying dietary tools that prevent disordered insulin secretion from pancreatic β-cells is an attractive strategy to combat the increasing prevalence of type 2 diabetes. Dietary resistant starch has been linked to improvements in the function of β-cells, possibly via increased colonic fermentation and production of short-chain fatty acids (SCFAs). Increasing the resistant starch content of commonly consumed foods could therefore maintain glucose homeostasis at the population level. As part of Biotechnology and Biological Sciences Research Council (BBSRC) Diet and Health Research Industry Club (DRINC) initiative, variants of Pisum sativum L. (pea) are being investigated to identify the features of pea starch that make it resistant to digestion and available for colonic fermentation and SCFA production. Parallel in vitro and in vivo studies are being conducted using both whole pea seeds and pea flour to facilitate a better understanding of how cells in the pea cotyledons are affected by processing and, in turn, how this influences starch digestibility. Trials in human volunteers are being used to monitor a full spectrum of short- and long-term physiological responses relevant to pancreatic β-cell function and glucose homeostasis. This project is providing new insights into variants of crops that are associated with the specific types of resistant starch that provide the best protection against defects in insulin secretion and function.
Pingitore A, Chambers ES, Hill T, et al., 2016, The diet-derived short chain fatty acid propionate improves beta-cell function in humans and stimulates insulin secretion from human islets in vitro, DIABETES OBESITY & METABOLISM, Vol: 19, Pages: 257-265, ISSN: 1462-8902
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