Imperial College London

ProfessorGaryFrost

Faculty of MedicineDepartment of Metabolism, Digestion and Reproduction

Chair in Nutrition and Dietetics
 
 
 
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Contact

 

+44 (0)20 7594 0959g.frost Website

 
 
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Location

 

Commonwealth BiuldingHammersmith HospitalHammersmith Campus

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Summary

 

Publications

Publication Type
Year
to

394 results found

Byrne CS, Blunt D, Burn J, Chambers E, Dagbasi A, Franco Becker G, Gibson G, Mendoza L, Murphy K, Poveda C, Ramgulam A, Tashkova M, Walton G, Washirasaksiri C, Frost Get al., 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, Pages: 258-258

<ns4:p><ns4:bold>Introduction:</ns4:bold> 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.</ns4:p><ns4:p> <ns4:bold>Methods:</ns4:bold> 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 <ns4:italic>in vitro</ns4:italic> continuous fermentation model will be inoculated with

Journal article

Wilson T, Garcia-Perez I, Posma JM, Lloyd AJ, Chambers ES, Tailliart K, Zubair H, Beckmann M, Mathers JC, Holmes E, Frost G, Draper Jet 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

Journal article

Greenwood DC, Hardie LJ, Frost GS, Alwan NA, Bradbury KE, Carter M, Elliott P, Evans CEL, Ford HE, Hancock N, Key TJ, Liu B, Morris MA, Mulla UZ, Petropoulou K, Potter GDM, Riboli E, Young H, Wark PA, Cade JEet al., 2019, Validation of the Oxford WebQ Online 24-hour dietary questionnaire using biomarkers, American Journal of Epidemiology, Vol: 188, Pages: 1858-1867, ISSN: 1476-6256

Oxford WebQ is an online dietary questionnaire covering 24 hours, appropriate for repeated administration in large-scale prospective studies including UK Biobank and the Million Women Study. We compared performance of the Oxford WebQ and a traditional interviewer-administered multi-pass 24-hour recall against biomarkers for protein, potassium and total sugar intake, and total energy expenditure estimated by accelerometry. 160 participants were recruited between 2014 and 2016 in London, UK, and measured at 3 non-consecutive time-points. The measurement error model simultaneously compared all 3 methods. Attenuation factors for protein, potassium, sugars and total energy intake estimated by the mean of 2 Oxford WebQs were 0.37, 0.42, 0.45, and 0.31 respectively, with performance improving incrementally for the mean of more measures. Correlation between the mean of 2 Oxford WebQs and estimated true intakes, reflecting attenuation when intake is categorised or ranked, was 0.47, 0.39, 0.40, and 0.38 respectively, also improving with repeated administration. These were similar to the more administratively burdensome interviewer-based recall. Using objective biomarkers as the standard, Oxford WebQ performs well across key nutrients in comparison with more administratively burdensome interviewer-based 24-hour recalls. Attenuation improves when the average is taken over repeated administration, reducing measurement error bias in assessment of diet-disease associations.

Journal article

Eriksen R, Gibson R, Aresu M, Heard A, Chan Q, Evangelou E, Gao H, Elliott P, Frost Get al., 2019, Gene-diet quality interactions on HbA1c and type 2 diabetes risk: The Airwave Health Monitoring Study, Endocrinology, Diabetes & Metabolism, Vol: 2, Pages: 1-7, ISSN: 2398-9238

Introduction: Type 2 Diabetes (T2D) is multi-factorial involving lifestyle, environmental and genetic risk factors. This study aims to investigate the impact of genetic interactions with alcohol and diet quality on glycated haemoglobin A1c (HbA1c) independent of obesity, in a British population.Methods: Cross-sectional study of 14,089 white British participants from Airwave Health Monitoring Study, and a sub-sample of 3,733 participants with dietary data. A T2D genetic risk score (GRS) was constructed and its interactions with diet on HbA1c were assessed.Results: GRS was associated with a higher HbA1c% ( 0.03, p<0.0001) and a higher risk of pre-diabetes (OR 1.09, p<0.0001) and T2D (OR 1.14, p 0.006). The genetic effect on HbA1c% was significantly higher in obese participants ( 1.88, pinteraction 0.03). A high intake of wholegrain attenuated the effect on HbA1c% in high-risk individuals pinteraction 0.04. Conclusion: The genetic effect on HbA1c was almost doubled in obese individuals, compared with those with a healthy weight, and independent of weight there was a modest offset on HbA1c in high-genetic risk individuals consuming a diet high in wholegrain. This supports the importance of a healthy diet high in wholegrains and along with maintaining a healthy weight in controlling HbA1c amongst high genetic risk groups.

Journal article

Maitland K, Olupot-Olupot P, Kiguli S, Chagaluka G, Alaroker F, Opoka RO, Mpoya A, Walsh K, Engoru C, Nteziyaremye J, Mallewa M, Kennedy N, Nakuya M, Namayanja C, Kayaga J, Nabawanuka E, Sennyondo T, Aromut D, Kumwenda F, Musika CW, Thomason MJ, Bates I, von Hensbroek MB, Evans JA, Uyoga S, Williams TN, Frost G, George EC, Gibb DM, Walker ASet al., 2019, Co-trimoxazole or multivitamin multimineral supplement for post-discharge outcomes after severe anaemia in African children: a randomised controlled trial, The Lancet Global Health, Vol: 7, Pages: e1435-e1447, ISSN: 2214-109X

BackgroundSevere anaemia is a leading cause of paediatric admission to hospital in Africa; post-discharge outcomes remain poor, with high 6-month mortality (8%) and re-admission (17%). We aimed to investigate post-discharge interventions that might improve outcomes.MethodsWithin the two-stratum, open-label, multicentre, factorial randomised TRACT trial, children aged 2 months to 12 years with severe anaemia, defined as haemoglobin of less than 6 g/dL, at admission to hospital (three in Uganda, one in Malawi) were randomly assigned, using sequentially numbered envelopes linked to a second non-sequentially numbered set of allocations stratified by centre and severity, to enhanced nutritional supplementation with iron and folate-containing multivitamin multimineral supplements versus iron and folate alone at treatment doses (usual care), and to co-trimoxazole versus no co-trimoxazole. All interventions were administered orally and were given for 3 months after discharge from hospital. Separately reported randomisations investigated transfusion management. The primary outcome was 180-day mortality. All analyses were done in the intention-to-treat population; follow-up was 180 days. This trial is registered with the International Standard Randomised Controlled Trial registry, ISRCTN84086586, and follow-up is complete.FindingsFrom Sept 17, 2014, to May 15, 2017, 3983 eligible children were randomly assigned to treatment, and followed up for 180 days. 164 (4%) were lost to follow-up. 1901 (95%) of 1997 assigned multivitamin multimineral supplement, 1911 (96%) of 1986 assigned iron and folate, and 1922 (96%) of 1994 assigned co-trimoxazole started treatment. By day 180, 166 (8%) children in the multivitamin multimineral supplement group versus 169 (9%) children in the iron and folate group had died (hazard ratio [HR] 0·97, 95% CI 0·79–1·21; p=0·81) and 172 (9%) who received co-trimoxazole versus 163 (8%) who did not receive co-trimoxazole h

Journal article

Wandrag L, Brett SJ, Frost G, To M, Loubo E, Jackson N, Umpleby M, Bountziouka V, Hickson Met al., 2019, Leucine-enriched essential amino acid supplementation in mechanically ventilated trauma patients – a feasibility study, Trials, Vol: 20, ISSN: 1745-6215

Background: Critically ill patients lose up to 2% muscle mass per day. We assessed the feasibility of administering a leucine-enriched essential amino acid (L-EAA) supplement to mechanically ventilated trauma patients with the aim of assessing the effect on skeletal muscle mass and function. Methods: A randomised feasibility study was performed over 6 months in intensive care (ICU), patients received 5g L-EAA five times per day in addition to standard feed (L-EAA group) or standard feed only (control group) up to 14 days. CRP, albumin, IL-6, IL-10, urinary 3-MH, nitrogen balance, protein turnover ([1-13C] leucine infusion), muscle depth change (ultrasound), functional change (Katz & Barthel indices) and muscle strength Medical Research Council (MRC) sum score to assess ICU Acquired Weakness, were measured sequentially.Results: Eight patients (9.5% of screened patients) were recruited over 6 months. L-EAA doses were provided on 91/124 (73%) occasions. Inflammatory and urinary marker data were collected; serial muscle depth measurements were lacking due to short length of stay. Protein turnover studies were performed on five occasions. MRC-sum score could not be performed as patients were not able to respond to the screening questions. The Katz & Barthel indices did not change. L-EAA delivery was achievable, but meaningful functional and muscle mass outcome measures require careful consideration in the design of a future RCT. Conclusion: L-EAA was practical to provide, but we found significant barriers to recruitment and measurement of the chosen outcomes which would need to be addressed in the design of a future, large randomised controlled trial.

Journal article

Wilman HR, Parisinos CA, Atabaki-Pasdar N, Kelly M, Thomas EL, Neubauer S, IMI DIRECT Consortium, Mahajan A, Hingorani AD, Patel RS, Hemingway H, Franks PW, Bell JD, Banerjee R, Yaghootkar Het al., 2019, Genetic studies of abdominal MRI data identify genes regulating hepcidin as major determinants of liver iron concentration, Journal of Hepatology, Vol: 71, Pages: 594-602, ISSN: 0168-8278

BACKGROUND & AIMS: Excess liver iron content is common and is linked to the risk of hepatic and extrahepatic diseases. We aimed to identify genetic variants influencing liver iron content and use genetics to understand its link to other traits and diseases. METHODS: First, we performed a genome-wide association study (GWAS) in 8,289 individuals from UK Biobank, whose liver iron level had been quantified by magnetic resonance imaging, before validating our findings in an independent cohort (n = 1,513 from IMI DIRECT). Second, we used Mendelian randomisation to test the causal effects of 25 predominantly metabolic traits on liver iron content. Third, we tested phenome-wide associations between liver iron variants and 770 traits and disease outcomes. RESULTS: We identified 3 independent genetic variants (rs1800562 [C282Y] and rs1799945 [H63D] in HFE and rs855791 [V736A] in TMPRSS6) associated with liver iron content that reached the GWAS significance threshold (p <5 × 10-8). The 2 HFE variants account for ∼85% of all cases of hereditary haemochromatosis. Mendelian randomisation analysis provided evidence that higher central obesity plays a causal role in increased liver iron content. Phenome-wide association analysis demonstrated shared aetiopathogenic mechanisms for elevated liver iron, high blood pressure, cirrhosis, malignancies, neuropsychiatric and rheumatological conditions, while also highlighting inverse associations with anaemias, lipidaemias and ischaemic heart disease. CONCLUSION: Our study provides genetic evidence that mechanisms underlying higher liver iron content are likely systemic rather than organ specific, that higher central obesity is causally associated with higher liver iron, and that liver iron shares common aetiology with multiple metabolic and non-metabolic diseases. LAY SUMMARY: Excess liver iron content is common and is associated with liver diseases and metabolic diseases including diabetes, high blood pressure, and heart

Journal article

Koivula RW, Forgie IM, Kurbasic A, Viñuela A, Heggie A, Giordano GN, Hansen TH, Hudson M, Koopman ADM, Rutters F, Siloaho M, Allin KH, Brage S, Brorsson CA, Dawed AY, De Masi F, Groves CJ, Kokkola T, Mahajan A, Perry MH, Rauh SP, Ridderstråle M, Teare HJA, Thomas EL, Tura A, Vestergaard H, White T, Adamski J, Bell JD, Beulens JW, Brunak S, Dermitzakis ET, Froguel P, Frost G, Gupta R, Hansen T, Hattersley A, Jablonka B, Kaye J, Laakso M, McDonald TJ, Pedersen O, Schwenk JM, Pavo I, Mari A, McCarthy MI, Ruetten H, Walker M, Pearson E, Franks PW, IMI DIRECT Consortiumet al., 2019, Discovery of biomarkers for glycaemic deterioration before and after the onset of type 2 diabetes: descriptive characteristics of the epidemiological studies within the IMI DIRECT Consortium., Diabetologia, Vol: 62, Pages: 1601-1615, ISSN: 0012-186X

AIMS/HYPOTHESIS: Here, we describe the characteristics of the Innovative Medicines Initiative (IMI) Diabetes Research on Patient Stratification (DIRECT) epidemiological cohorts at baseline and follow-up examinations (18, 36 and 48 months of follow-up). METHODS: From a sampling frame of 24,682 adults of European ancestry enrolled in population-based cohorts across Europe, participants at varying risk of glycaemic deterioration were identified using a risk prediction algorithm (based on age, BMI, waist circumference, use of antihypertensive medication, smoking status and parental history of type 2 diabetes) and enrolled into a prospective cohort study (n = 2127) (cohort 1, prediabetes risk). We also recruited people from clinical registries with type 2 diabetes diagnosed 6-24 months previously (n = 789) into a second cohort study (cohort 2, diabetes). Follow-up examinations took place at ~18 months (both cohorts) and at ~48 months (cohort 1) or ~36 months (cohort 2) after baseline examinations. The cohorts were studied in parallel using matched protocols across seven clinical centres in northern Europe. RESULTS: Using ADA 2011 glycaemic categories, 33% (n = 693) of cohort 1 (prediabetes risk) had normal glucose regulation and 67% (n = 1419) had impaired glucose regulation. Seventy-six per cent of participants in cohort 1 was male. Cohort 1 participants had the following characteristics (mean ± SD) at baseline: age 62 (6.2) years; BMI 27.9 (4.0) kg/m2; fasting glucose 5.7 (0.6) mmol/l; 2 h glucose 5.9 (1.6) mmol/l. At the final follow-up examination the participants' clinical characteristics were as follows: fasting glucose 6.0 (0.6) mmol/l; 2 h OGTT glucose 6.5 (2.0) mmol/l. In cohort 2 (diabetes), 66% (n = 517) were treated by lifestyle modification and 34% (n = 272) were treated with metformin plus lifestyle modification at enro

Journal article

Gibson R, Eriksen R, Chambers E, Gao H, Aresu M, Heard A, Chan Q, Elliott P, Frost Get 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.

Journal article

Sukkar A, Lett A, Frost G, Chambers Eet 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.

Journal article

Maitland K, Kiguli S, Olupot-Olupot P, Engoru C, Mallewa M, Goncalves PS, Opoka RO, Mpoya A, Alaroker F, Nteziyaremye J, Chagaluka G, Kennedy N, Nabawanuka E, Nakuya M, Namayanja C, Uyoga S, Byabazaire DK, M'baya B, Wabwire B, Frost G, Bates I, Evans JA, Williams TN, George EC, Gibb DM, Walker ASet al., 2019, Immediate transfusion in African children with uncomplicated severe anemia, New England Journal of Medicine, Vol: 381, Pages: 407-419, ISSN: 0028-4793

BackgroundThe World Health Organization recommends not performing transfusions in African children hospitalized for uncomplicated severe anemia (hemoglobin level of 4 to 6 g per deciliter and no signs of clinical severity). However, high mortality and readmission rates suggest that less restrictive transfusion strategies might improve outcomes.MethodsIn this factorial, open-label, randomized, controlled trial, we assigned Ugandan and Malawian children 2 months to 12 years of age with uncomplicated severe anemia to immediate transfusion with 20 ml or 30 ml of whole-blood equivalent per kilogram of body weight, as determined in a second simultaneous randomization, or no immediate transfusion (control group), in which transfusion with 20 ml of whole-blood equivalent per kilogram was triggered by new signs of clinical severity or a drop in hemoglobin to below 4 g per deciliter. The primary outcome was 28-day mortality. Three other randomizations investigated transfusion volume, postdischarge supplementation with micronutrients, and postdischarge prophylaxis with trimethoprim–sulfamethoxazole.ResultsA total of 1565 children (median age, 26 months) underwent randomization, with 778 assigned to the immediate-transfusion group and 787 to the control group; 984 children (62.9%) had malaria. The children were followed for 180 days, and 71 (4.5%) were lost to follow-up. During the primary hospitalization, transfusion was performed in all the children in the immediate-transfusion group and in 386 (49.0%) in the control group (median time to transfusion, 1.3 hours vs. 24.9 hours after randomization). The mean (±SD) total blood volume transfused per child was 314±228 ml in the immediate-transfusion group and 142±224 ml in the control group. Death had occurred by 28 days in 7 children (0.9%) in the immediate-transfusion group and in 13 (1.7%) in the control group (hazard ratio, 0.54; 95% confidence interval [CI], 0.22 to 1.36; P=0.19) and by 180 days in

Journal article

Chambers E, Byrne C, Rugyendo A, Morrison D, Preston T, Tedford C, Bell J, Thomas L, Akbar A, Riddell N, Sharma R, Thursz M, Manousou P, Frost Get 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.

Journal article

Maitland K, Olupot-Olupot P, Kiguli S, Chagaluka G, Alaroker F, Opoka RO, Mpoya A, Engoru C, Nteziyaremye J, Mallewa M, Kennedy N, Nakuya M, Namayanja C, Kayaga J, Uyoga S, Byabazaire DK, M'baya B, Wabwire B, Frost G, Bates I, Evans JA, Williams TN, Goncalves PS, George EC, Gibb DM, Walker ASet al., 2019, Transfusion Volume for Children with Severe Anemia in Africa, New England Journal of Medicine, Vol: 381, Pages: 420-431, ISSN: 0028-4793

BackgroundSevere anemia (hemoglobin level, <6 g per deciliter) is a leading cause of hospital admission and death in children in sub-Saharan Africa. The World Health Organization recommends transfusion of 20 ml of whole-blood equivalent per kilogram of body weight for anemia, regardless of hemoglobin level.MethodsIn this factorial, open-label trial, we randomly assigned Ugandan and Malawian children 2 months to 12 years of age with a hemoglobin level of less than 6 g per deciliter and severity features (e.g., respiratory distress or reduced consciousness) to receive immediate blood transfusion with 20 ml per kilogram or 30 ml per kilogram. Three other randomized analyses investigated immediate as compared with no immediate transfusion, the administration of postdischarge micronutrients, and postdischarge prophylaxis with trimethoprim–sulfamethoxazole. The primary outcome was 28-day mortality.ResultsA total of 3196 eligible children (median age, 37 months; 2050 [64.1%] with malaria) were assigned to receive a transfusion of 30 ml per kilogram (1598 children) or 20 ml per kilogram (1598 children) and were followed for 180 days. A total of 1592 children (99.6%) in the higher-volume group and 1596 (99.9%) in the lower-volume group started transfusion (median, 1.2 hours after randomization). The mean (±SD) volume of total blood transfused per child was 475±385 ml and 353±348 ml, respectively; 197 children (12.3%) and 300 children (18.8%) in the respective groups received additional transfusions. Overall, 55 children (3.4%) in the higher-volume group and 72 (4.5%) in the lower-volume group died before 28 days (hazard ratio, 0.76; 95% confidence interval [CI], 0.54 to 1.08; P=0.12 by log-rank test). This finding masked significant heterogeneity in 28-day mortality according to the presence or absence of fever (>37.5°C) at screening (P=0.001 after Sidak correction). Among the 1943 children (60.8%) without fever, mortality was lower with

Journal article

Maitland K, Olupot-Olupot P, Kiguli S, Chagaluka G, Alaroker F, Opoka RO, Mpoya A, Walsh K, Engoru C, Nteziyaremye J, Mallewa M, Kennedy N, Nakuya M, Namayanja C, Kayaga J, Nabawanuka E, Sennyondo T, Aromut D, Williams Musika C, Kumwenda F, Thomason M, Bates I, Boele von Hensbroek M, Evans JA, Uyoga S, Williams TN, Frost G, George EC, Gibb DM, Walker ASet al., Cotrimoxazole or multi-mineral multi-vitamins to improve post-discharge outcomes following severe anaemia in African children: a randomised controlled trial, The Lancet Global Health, ISSN: 2214-109X

Background: Severe anaemia (haemoglobin<6g/dl) is a leading cause of paediatric admission inAfrica; post-discharge outcomes remain poor with high 6-month mortality (8%) and re-admission(17%). This trial aimed to investigate pragmatic post-discharge interventions that might improveoutcomes.Methods: Within the factorial open-label TRACT trial, Ugandan and Malawian children aged 2months-12 years with severe anaemia (haemoglobin <6g/dl) at hospital admission wererandomised (using sequentially-numbered envelopes linked to a second set of non-sequentiallynumbered allocations, stratified by centre and severity) to enhanced nutritional supplementationwith iron and folate-containing multi-vitamin multi-mineral supplements (MVMM) or iron/folateat treatment doses (usual care), and to cotrimoxazole versus no cotrimoxazole, both given for 3months post-discharge. Separately-reported randomisations investigated transfusionmanagement. The primary outcome was 180-day mortality analysed by intention-to-treat; followup was to 180-days (completed).Findings: 3983 eligible children were randomised and followed for 180-days [164(4%) lost-tofollow-up]. Treatment was initiated in 1901(95%) MVMM, 1911(96%) iron/folate and 1922(96%)cotrimoxazole. By day-180, 166(8%) MVMM vs 169(9%) iron/folate had died (hazardratio(HR)=0.97 (95% CI 0.79-1.21); p=0.81) and 172(9%) cotrimoxazole vs 163(8%) nocotrimoxazole had died (HR=1.07 (95% CI 0.86-1.32); p=0.56). No evidence was seen ofinteractions between these randomisations or with transfusion randomisations (p>0.2). By day180, 489(24%) MVMM vs 509(26%) iron/folate had experienced one or more SAEs (HR=0.95 (0.84-1.07), p=0.40) and 500(25%) cotrimoxazole vs 498(25%) no cotrimoxazole (HR=1.01 (0.89,1.15)p=0.85). Most SAEs were readmissions, occurring in 692(17%) children (175(4%) with ≥2 readmissions).Interpretation: Neither enhanced supplementation with MVMM versus iron/folate treatment orcotrimoxazole prophylaxis improved 6-month survival. H

Journal article

Ek A, Nystrom CD, Chirita-Emandi A, Tur JA, Nordin K, Bouzas C, Argelich E, Alfredo Martinez J, Frost G, Garcia-Perez I, Saez M, Paul C, Lof M, Nowicka Pet al., 2019, A randomized controlled trial for overweight and obesity in preschoolers: the More and Less Europe study- an intervention within the STOP project, BMC PUBLIC HEALTH, Vol: 19, ISSN: 1471-2458

Journal article

Chambers E, Byrne C, Morrison D, Murphy K, Preston T, Tedford MC, Garcia Perez I, Fountana S, Serrano Contreras J, Holmes E, Roberts J, Reynolds C, Boyton R, Altmann D, McDonald J, Marchesi J, Akbar A, Riddell N, Wallis G, Frost Get 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.

Journal article

van Bussel IPG, Fazelzadeh P, Frost GS, Rundle M, Afman LAet al., Measuring phenotypic flexibility by transcriptome time-course analyses during challenge tests before and after energy restriction., FASEB J, Pages: fj201900148R-fj201900148R

Metabolic challenge tests may be a valuable tool to magnify the effects of diet on health. The use of transcriptomics enables a more extensive characterization of the effects of diet. The question remains whether transcriptome time-course analyses during challenge tests will deliver more information on the effect of diet than a static fasting measurement. A dietary intervention known to improve health is energy restriction (ER). Seventy-two healthy, overweight men and women aged 50-65 were subjected to an oral glucose tolerance test (OGTT) and a mixed-meal test (MMT) before and after 12 wk of a 20% ER diet or control diet. Whole-genome gene expression of peripheral blood mononuclear cells was performed before and after the intervention. This was done during fasting, during the OGTT at 30, 60, and 120 min, and during the MMT at 60, 120, 240, and 360 min. Upon ER, the OGTT resulted in a faster and more pronounced down-regulation in gene expression of oxidative phosphorylation, cell adhesion, and DNA replication compared with the control. The MMT showed less-consistent effects. The OGTT combined with transcriptomics can be used to measure dynamic cellular adaptation upon an intervention that cannot be determined with a static fasting measurement.-Van Bussel, I. P. G., Fazelzadeh, P., Frost, G. S., Rundle, M., Afman, L. A., NutriTech Consortium. Measuring phenotypic flexibility by transcriptome time-course analyses during challenge tests before and after energy restriction.

Journal article

Behary P, Tharakan G, Alexiadou K, Johnson N, Wewer Albrechtsen NJ, Kenkre J, Cuenco J, Hope D, Anyiam O, Choudhury S, Alessimii H, Poddar A, Minnion J, Doyle C, Frost G, Le Roux C, Purkayastha S, Moorthy K, Dhillo W, Holst JJ, Ahmed AR, Prevost AT, Bloom SR, Tan TMet al., 2019, Combined GLP-1, oxyntomodulin, and peptide YY improves body weight and glycemia in obesity and prediabetes/type 2 diabetes: a randomized single-blinded placebo controlled study, Diabetes Care, Vol: 42, Pages: 1446-1453, ISSN: 0149-5992

OBJECTIVE: Roux-en-Y gastric bypass (RYGB) augments postprandial secretion of glucagon-like peptide 1 (GLP-1), oxyntomodulin (OXM), and peptide YY (PYY). Subcutaneous infusion of these hormones ("GOP"), mimicking postprandial levels, reduces energy intake. Our objective was to study the effects of GOP on glycemia and body weight when given for 4 weeks to patients with diabetes and obesity. RESEARCH DESIGN AND METHODS: In this single-blinded mechanistic study, obese patients with prediabetes/diabetes were randomized to GOP (n = 15) or saline (n = 11) infusion for 4 weeks. We also studied 21 patients who had undergone RYGB and 22 patients who followed a very low-calorie diet (VLCD) as unblinded comparators. Outcomes measured were 1) body weight, 2) fructosamine levels, 3) glucose and insulin during a mixed meal test (MMT), 4) energy expenditure (EE), 5) energy intake (EI), and 6) mean glucose and measures of glucose variability during continuous glucose monitoring. RESULTS: GOP infusion was well tolerated over the 4-week period. There was a greater weight loss (P = 0.025) with GOP (mean change -4.4 [95% CI -5.3, -3.5] kg) versus saline (-2.5 [-4.1, -0.9] kg). GOP led to a greater improvement (P = 0.0026) in fructosamine (-44.1 [-62.7, -25.5] µmol/L) versus saline (-11.7 [-18.9, -4.5] µmol/L). Despite a smaller weight loss compared with RYGB and VLCD, GOP led to superior glucose tolerance after a mixed-meal stimulus and reduced glycemic variability compared with RYGB and VLCD. CONCLUSIONS: GOP infusion improves glycemia and reduces body weight. It achieves superior glucose tolerance and reduced glucose variability compared with RYGB and VLCD. GOP is a viable alternative for the treatment of diabetes with favorable effects on body weight.

Journal article

Wijeyesekera A, Wagner J, De Goffau M, Thurston S, Rodrigues Sabino A, Zaher S, White D, Ridout J, Peters MJ, Ramnarayan P, Branco RG, Torok ME, Valla F, Meyer R, Klein N, Frost G, Parkhill J, Holmes E, Pathan Net al., 2019, Multi-compartment profiling of bacterial and host metabolites identifies intestinal dysbiosis and its functional consequences in the critically ill child, Critical Care Medicine, Vol: 47, Pages: e727-e734, ISSN: 0090-3493

OBJECTIVES: Adverse physiology and antibiotic exposure devastate the intestinal microbiome in critical illness. Time and cost implications limit the immediate clinical potential of microbial sequencing to identify or treat intestinal dysbiosis. Here, we examined whether metabolic profiling is a feasible method of monitoring intestinal dysbiosis in critically ill children. DESIGN: Prospective multicenter cohort study. SETTING: Three U.K.-based PICUs. PATIENTS: Mechanically ventilated critically ill (n = 60) and age-matched healthy children (n = 55). INTERVENTIONS: Collection of urine and fecal samples in children admitted to the PICU. A single fecal and urine sample was collected in healthy controls. MEASUREMENTS AND MAIN RESULTS: Untargeted and targeted metabolic profiling using 1H-nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry or urine and fecal samples. This was integrated with analysis of fecal bacterial 16S ribosomal RNA profiles and clinical disease severity indicators. We observed separation of global urinary and fecal metabolic profiles in critically ill compared with healthy children. Urinary excretion of mammalian-microbial co-metabolites hippurate, 4-cresol sulphate, and formate were reduced in critical illness compared with healthy children. Reduced fecal excretion of short-chain fatty acids (including butyrate, propionate, and acetate) were observed in the patient cohort, demonstrating that these metabolites also distinguished between critical illness and health. Dysregulation of intestinal bile metabolism was evidenced by increased primary and reduced secondary fecal bile acid excretion. Fecal butyrate correlated with days free of intensive care at 30 days (r = 0.38; p = 0.03), while urinary formate correlated inversely with vasopressor requirement (r = -0.2; p = 0.037). CONCLUSIONS: Disruption to the functional activity of the intestinal microbiome may result in worsening organ failure in the critically ill child. P

Journal article

McCrory M, Sun M, Sazonov E, Frost G, Anderson A, Jia W, Jobarteh ML, Maitland K, Steiner-Asiedu M, Ghosh T, Higgins JA, Baranowski T, Lo Bet al., 2019, Methodology for objective, passive, image- and sensor-based assessment of dietary intake, meal-timing, and food-related activity in Ghana and Kenya (P13-028-19)., Current Developments in Nutrition, Vol: 3, Pages: 1247-1247, ISSN: 2475-2991

Objectives: Herein we describe a new system we have developed for assessment of dietary intake, meal timing, and food-related activities, adapted for use in low- and middle-income countries. Methods: System components include one or more wearable cameras (the Automatic Ingestion Monitor-2 (AIM), an eyeglasses-mounted wearable chewing sensor and micro-camera; ear-worn camera; the eButton, a camera attached to clothes; and eHat, a camera attached to a visor worn by the mother when feeding infants and toddlers), and custom software for evaluation of dietary intake from food-based images and sensor-detected food intake. General protocol: The primary caregiver of the family uses one or more wearable cameras during all waking hours. The cameras aim directly in front of the participant and capture images every few seconds, thereby providing multiple images of all food-related activities throughout the day. The camera may be temporarily removed for short periods to preserve privacy, such as during bathing and personal care. For analysis, images and sensor signals are processed by the study team in custom software. The images are time-stamped, arranged in chronological order, and linked with sensor-detected eating occasions. The software also incorporates food composition databases of choice such as the West African Foods Database, a Kenyan Foods Database, and the USDA Food Composition Database, allowing for image-based dietary assessment by trained nutritionists. Images can be linked with nutritional analysis and tagged with an activity label (e.g., food shopping, child feeding, cooking, eating). Assessment of food-related activities such as food-shopping, food gathering from gardens, cooking, and feeding of other family members by the primary caregiver can help provide context for dietary intake and additional information to increase accuracy of dietary assessment and analysis of eating behavior. Examples of the latter include assessment of specific ingredients in prepared

Journal article

Maitland K, Kiguli S, Olupot-Olupot P, Engoru C, Mellewa M, Goncalves PS, Opoka RO, Mpoya A, Alaroker F, Nteziyaremye J, Chagaluka G, Kennedy N, Nabawanuka E, Nakuya M, Namayanja C, Uyoga S, Byabazaire DK, Mbaya B, Wabwire B, Frost G, Bates I, Evans JA, Williams T, George EC, Gibb DM, Walker ASet al., Transfusion in African Children with Uncomplicated Severe Anemia, New England Journal of Medicine, ISSN: 0028-4793

Journal article

Rahman MS, Vorkas P, Frost G, Morrison D, Haskard D, Woollard KJet al., 2019, OUTLINING THE HUMAN MONOCYTE INFLAMMATORY CYTOKINE RESPONSE TO DIETARY FAT INTAKE, Annual Conference of the British-Cardiovascular-Society (BCS) - Digital Health Revolution, Publisher: BMJ PUBLISHING GROUP, Pages: A159-A160, ISSN: 1355-6037

Conference paper

Byrne C, Chambers E, Brignardello J, Garcia-Perez I, Holmes E, Gareth W, Tom P, Catriona T, Douglas M, Gary S Fet 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.

Journal article

Byrne C, Blunt D, Burn J, Chambers E, Dagbasi A, Franco Becker G, Gibson G, Mendoza L, Murphy K, Poveda C, Ramgulam A, Tashkova M, Walton G, Washirasaksiri C, Frost Get 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

Journal article

Brown AC, Taheri S, Dornhorst A, McGowan B, Leeds AR, Omar O, Frost Get al., 2019, The impact of a formula low energy diet on weight outcomes and insulin use in insulin-treated obese Type 2 diabetes patients, Publisher: WILEY, Pages: 92-93, ISSN: 0742-3071

Conference paper

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

Journal article

Pingitore A, Gonzalez-Abuin N, Ruz-Maldonado I, Huang GC, Frost G, Persaud SJet al., 2019, Short chain fatty acids stimulate insulin secretion and reduce apoptosis in mouse and human islets in vitro: Role of free fatty acid receptor 2, DIABETES OBESITY & METABOLISM, Vol: 21, Pages: 330-339, ISSN: 1462-8902

Journal article

Consortium H, Drake L, Frost G, Holmes E, Lett A, Maitland K, Marchesi J, Swann J, thompson, Thompson A, Walsh Ket al., 2019, Health outcomes in Undernutrition: the role of Nutrients, Gut dysfunction and the gut microbiome (HUNGer), Health outcomes in Undernutrition: the role of Nutrients, Gut dysfunction and the gut microbiome (HUNGer), Publisher: Imperial College London

The HUNGer consortium is comprised of a multi-disciplinary, multi-national consortium of world leading researchers, with expertise in physiology and nutrition, through to clinical research, public health and agriculture in LMIC settings. The HUNGer consortium was awarded the MRC Confidence in Global Nutrition and Health award in 2018.The HUNGer consortium is developing a programme of work that will directly address United Nations Sustainable Development Goal 2 (SDG-2): End hunger, achieve food security and improve nutrition, and promote sustainable agriculture. We believe there are a number of critical unanswered questions regarding the role of the gut in undernutrition, which if answered could significantly improve the effective management and prevention of undernutrition.The following document represents the consensus opinion of the HUNGer consortium concerning the key challenges that currently limit the effective management and prevention of undernutrition and the most promising potential solutions.

Report

Khatib M, Chambers E, Morrison DJ, Frost Get al., 2019, A pilot study to evaluate the effect of increased colonic propionate on glucose homeostasis during a hypocaloric diet, Publisher: CAMBRIDGE UNIV PRESS, Pages: E10-E10, ISSN: 0029-6651

Conference paper

Wandrag L, Brett SJ, Frost GS, Bountziouka V, Hickson Met al., 2019, Exploration of muscle loss and metabolic state during prolonged critical illness: Implications for intervention?, PLoS One, Vol: 14

BACKGROUND: Muscle wasting in the critically ill is up to 2% per day and delays patient recovery and rehabilitation. It is linked to inflammation, organ failure and severity of illness. The aims of this study were to understand the relationship between muscle depth loss, and nutritional and inflammatory markers during prolonged critical illness. Secondly, to identify when during critical illness catabolism might decrease, such that targeted nutritional strategies may logically be initiated. METHODS: This study was conducted in adult intensive care units in two large teaching hospitals. Patients anticipated to be ventilated for >48 hours were included. Serum C-reactive protein (mg/L), urinary urea (mmol/24h), 3-methylhistidine (μmol/24h) and nitrogen balance (g/24h) were measured on days 1, 3, 7 and 14 of the study. Muscle depth (cm) on ultrasound were measured on the same days over the bicep (bicep and brachialis muscle), forearm (flexor compartment of muscle) and thigh (rectus femoris and vastus intermedius). RESULTS: Seventy-eight critically ill patients were included with mean age of 59 years (SD: 16) and median Intensive care unit (ICU) length of stay of 10 days (IQR: 6-16). Starting muscle depth, 8.5cm (SD: 3.2) to end muscle depth, 6.8cm (SD: 2.2) were on average significantly different over 14 days, with mean difference -1.67cm (95%CI: -2.3 to -1cm), p<0.0001. Protein breakdown and inflammation continued over 14 days of the study. CONCLUSION: Our patients demonstrated a continuous muscle depth loss and negative nitrogen balance over the 14 days of the study. Catabolism remained dominant throughout the study period. No obvious 'nutritional tipping point" to identify anabolism or recovery could be identified in our cohort. Our ICU patient cohort is one with a moderately prolonged stay. This group showed little consistency in data, reflecting the individuality of both disease and response. The data are consistent with a conclusion that a time based

Journal article

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