This study investigated the impact of ACTAZIN™ green (2400 and 600 mg) and Livaux™ (2400 mg) gold kiwifruit supplements on faecal microbial composition and metabolites in healthy and functionally constipated (FC) participants. The participants were recruited into the healthy group (n 20; one of whom did not complete the study) and the FC group (n 9), each of whom consumed all the treatments and a placebo (isomalt) for 4 weeks in a randomised cross-over design interspersed with 2-week washout periods. Modification of faecal microbiota composition and metabolism was determined by 16S rRNA gene sequencing and GC, and colonic pH was calculated using SmartPill® wireless motility capsules. A total of thirty-two taxa were measured at greater than 1 % abundance in at least one sample, ten of which differed significantly between the baseline healthy and FC groups. Specifically, Bacteroidales and Roseburia spp. were significantly more abundant (P < 0·05) in the healthy group and taxa including Ruminococcaceae, Dorea spp. and Akkermansia spp. were significantly more abundant (P < 0·05) in the FC group. In the FC group, Faecalibacterium prausnitzii abundance significantly increased (P = 0·024) from 3·4 to 7·0 % following Livaux™ supplementation, with eight of the nine participants showing a net increase. Lower proportions of F. prausnitzii are often associated with gastrointestinal disorders. The discovery that Livaux™ supplementation increased F. prausnitzii abundance offers a potential strategy for improving gut microbiota composition, as F. prausnitzii is a butyrate producer and has also been shown to exert anti-inflammatory effects in many studies.

Vitamin A equivalency of β-carotene (VEB) is defined as the amount of ingested β-carotene in μg that is absorbed and converted into 1 μg retinol (vitamin A) in the human body. The objective of the present review was to discuss the different estimates for VEB in various types of dietary food matrices. Different methods are discussed such as mass balance, dose–response and isotopic labelling. The VEB is currently estimated by the US Institute of Medicine (IOM) as 12:1 in a mixed diet and 2:1 in oil. For humans consuming β-carotene dissolved in oil, a VEB between 2:1 and 4:1 is feasible. A VEB of approximately 4:1 is applicable for biofortified cassava, yellow maize and Golden Rice, which are specially bred for human consumption in developing countries. We propose a range of 9:1–16:1 for VEB in a mixed diet that encompasses the IOM VEB of 12:1 and is realistic for a Western diet under Western conditions. For a ‘prudent’ (i.e. non-Western) diet including a variety of commonly consumed vegetables, a VEB could range from 9:1 to 28:1 in a mixed diet.

Many clinical and epidemiological studies have shown that the polyunsaturated n-3 fatty acids EPA and DHA from fish and fish oils, provide cardiovascular protection, particularly in the setting of secondary prevention. n-3 Fatty acids beneficially influence a number of cardiometabolic risk factors including blood pressure, cardiac function, vascular reactivity and lipids, as well as having anti-platelet, anti-inflammatory and anti-oxidative actions. They do not appear to adversely interact with other medications such as statins and other lipid-lowering drugs or antihypertensive medications. n-3 Fatty acids have gained widespread usage by general practitioners and clinicians in a number of clinical settings such as pregnancy and infant development, secondary prevention in CHD patients, treatment of dyslipidaemias and haemodialysis patients. Small doses are achievable with consumption of two to three oily fish meals per week or via purified encapsulated preparations now readily available. n-3 Fatty acids, particularly when consumed as fish, should be considered an important component of a healthy diet. The present paper reviews the effects of n-3 fatty acids on cardiometabolic risk factors, concentrating particularly on the evidence from randomised controlled studies in human subjects.

Gastrointestinal hormones and Ca are associated with bone metabolism. The objective of the present human study was to determine the effect of calcium phosphate on the postprandial circulation of gastrointestinal hormones. A total of ten men participated in the present double-blind, placebo-controlled, cross-over study. The participants were divided into two groups. Of these, one group consumed bread enriched with 1 g Ca (pentacalcium hydroxy-triphosphate, CaP) daily for 3 weeks. The other group consumed placebo bread. After 2 weeks of washout, the intervention was changed between the groups for another 3 weeks. The subjects consumed a defined diet at the beginning (single administration) and at the end (repeated administration) of the intervention periods, and blood samples were drawn at 0, 30, 60, 120, 180 and 240 min. Between 0 and 30 min, the participants consumed a test meal, with or without CaP. The concentrations of gastrointestinal hormones (glucose-dependent insulinotropic polypeptide, glucagon-like peptide (GLP) 1 and GLP2), insulin and glucose were determined. The AUC of GLP1 (total and active) and GLP2 increased significantly after the repeated CaP administrations compared with that after placebo administration. The AUC of insulin and glucose showed no differences between the CaP and placebo administrations. CaP affects the postprandial plasma concentrations of gastrointestinal hormones through the modulation of the intestinal environment, e.g. bile acids and microbiota.

Vitamin A (VA) deficiency causes disability and mortality. Cassava can be crossbred to improve its β-carotene (BC) content; typical white cassava contains negligible amounts of BC. However, cassava contains cyanide and its continued consumption may lead to chronic disability. Our objective was to estimate the risk–benefit of consuming BC-enhanced cassava to increase VA intake. A total of ten American women were fed white and BC-enhanced cassava. BC and cyanide data from the feeding study were combined with African cassava consumption data to model the potential daily BC, VA and cyanide intakes of African women. If BC-enhanced cassava replaced white cassava in the diets, it could theoretically meet recommended VA intakes for the following percentages of individuals from six African countries that consume cassava as a staple crop: Angola (95 %), Central African Republic (95 %), Congo (about 100 %), Ghana (99 %), Mozambique (99 %) and Nigeria (92 %). Cyanide intake after minimal preparation of cassava could be thirteen to thirty-two times the reference dose (RfD), a toxicological exposure reference, but could be completely removed by extensive soaking. This study demonstrates that consumption of BC-enhanced cassava, processed to maintain BC and remove cyanide, theoretically increases VA intakes for African populations and other areas of the world where cassava is a staple crop.

Biofortification of cassava with the provitamin A carotenoid β-carotene is a potential mechanism for alleviating vitamin A deficiency. Cassava is a staple food in the African diet, but data regarding the human bioavailability of β-carotene from this food are scarce. The objective of the present study was to evaluate provitamin A-enhanced cassava as a source of β-carotene and vitamin A for healthy adult women. The study was a randomised, cross-over trial of ten American women. The subjects consumed three different porridges separated by 2 week washout periods. Treatment meals (containing 100 g cassava) included: biofortified cassava (2 mg β-carotene) porridge with added oil (15 ml peanut or rapeseed oil, 20 g total fat); biofortified cassava porridge without added oil (6 g total fat); unfortified white cassava porridge with a 0·3 mg retinyl palmitate reference dose and added oil (20 g total fat). Blood was collected six times from − 0·5 to 9·5 h post-feeding. TAG-rich lipoprotein (TRL) plasma was separated by ultracentrifugation and analysed using HPLC with coulometric array electrochemical detection. The AUC for retinyl palmitate increased after the biofortified cassava meals were fed (P< 0·05). Vitamin A conversion was 4·2 (sd 3·1) and 4·5 (sd 3·1) μg β-carotene:1 μg retinol, with and without added oil, respectively. These results show that biofortified cassava increases β-carotene and retinyl palmitate TRL plasma concentrations in healthy well-nourished adult women, suggesting that it is a viable intervention food for preventing vitamin A deficiency.

We conducted a double-blind, placebo-controlled trial to evaluate the effect of heat-killed cells of Lactococcus lactis strain H61 on various skin properties of Japanese women. Volunteers (age 31–62 years) were randomly assigned to receive test food with or without 60 mg of heat-killed strain H61 (fifteen women in each group; H61 and control groups, respectively) daily for 8 weeks. Results were analysed for three age categories (30s, 40s and 50–60s). Compared with that at week 0, skin hydration at the inner forearm at weeks 4 and 8 decreased in all volunteers (except those in their 50–60s) because of the environmental change from autumn to winter. The oldest H61 group maintained skin hydration at the inner forearm throughout the study. Skin elasticity and melanin content in the cheek decreased and sebum content increased throughout the test period due to seasonal environmental change, regardless of age or H61 treatment. Self-evaluation scores for apparent hair follicles and dryness of the throat at week 8 were higher in the overall H61 group than in the combined placebo group. The 30s H61 group noted marked improvements in self-surveyed skin elasticity at week 8 compared with at week 0 and with the placebo group at week 8. The results of the present study indicate that oral intake of heat-killed cells of L. lactis strain H61 can improve some skin properties and body characteristics in women. This strain would probably be useful in increasing the quality of life in an ageing population.

The flavonol quercetin, is one of the major flavonoids found in edible plants. The bioavailability of quercetin in humans may be influenced by the food matrix in which it is consumed as well as by its chemical and physical form. The objective of the present study was to investigate the biokinetics of quercetin from quercetin-enriched cereal bars and quercetin powder-filled hard capsules. In a randomised, single-blinded, diet-controlled cross-over study, six healthy women aged 22–28 years took a single oral dose of approximately 130 mg quercetin equivalents from either quercetin-enriched cereal bars (containing 93·3 % quercetin aglycone plus 6·7 % quercetin-4′-glucoside) or quercetin powder-filled hard capsules (100 % quercetin aglycone). Blood samples were drawn before and after quercetin administration over a 24 h period. The concentrations of quercetin and its monomethylated derivatives, isorhamnetin (3′-O-methyl quercetin) and tamarixetin (4′-O-methyl quercetin), were measured by HPLC with fluorescence detection after plasma enzymatic treatment. The systemic availability as determined by comparing the plasma concentration–time curves of quercetin was found to be five times and the cmax values six times higher after ingestion of 130 mg quercetin by quercetin-enriched cereal bars than after ingestion by quercetin capsules. In contrast, tmax did not differ significantly between the two treatments. The cmax values for isorhamnetin and tamarixetin were four and nine times higher after ingestion of quercetin by quercetin-enriched cereal bars than after ingestion by quercetin capsules. In conclusion, quercetin from quercetin-enriched cereal bars is significantly more bioavailable than from quercetin powder-filled hard capsules.

Moderate wine consumption has been shown to lower cardiovascular risk. One of the mechanisms could involve the control of postprandial hyperlipaemia, a well-defined risk factor for atherosclerosis, reasonably by reducing the absorption of lipid oxidised species from the meal. The objective of the present study was to investigate whether wine consumption with the meal is able to reduce the postprandial increase in plasma lipid hydroperoxides and cholesterol oxidation products, in human subjects. In two different study sessions, twelve healthy volunteers consumed the same test meal rich in oxidised and oxidisable lipids (a double cheeseburger), with 300 ml of water (control) or with 300 ml of red wine (wine). The postprandial plasma concentration of cholesterol oxidation products was measured by GC–MS. The control meal induced a significant increase in the plasma concentration of lipid hydroperoxides and of two cholesterol oxidation products, 7-β-hydroxycholesterol and 7-ketocholesterol. The postprandial increase in lipid hydroperoxides and cholesterol oxidation products was fully prevented by wine when consumed with the meal. In conclusion, the present study provides evidence that consumption of wine with the meal could prevent the postprandial increase in plasma cholesterol oxidation products.

Purinergic receptors are important for the regulation of inflammation, muscle contraction, neurotransmission and nociception. Extracellular ATP and its metabolites are the main ligands for these receptors. Occasional reports on beneficial results of ATP administration in human and animal studies have suggested the bioavailability of oral ATP supplements. We investigated whether prolonged daily intake of oral ATP is indeed bioavailable. Thirty-two healthy subjects were randomised to receive 0, 250, 1250 or 5000 mg ATP per d for 28 d by means of enteric-coated pellets. In addition, on days 0 and 28, all thirty-two subjects received 5000 mg ATP to determine whether prolonged administration would induce adaptations in the bioavailability of ATP. ATP supplementation for 4 weeks did not lead to changes in blood or plasma ATP concentrations. Of all ATP metabolites, only plasma uric acid levels increased significantly after the administration of 5000 mg of ATP. Prolonged administration of ATP was safe as evidenced from liver and kidney parameters. We conclude that oral administration of ATP only resulted in increased uric acid concentrations. On the basis of these findings, we seriously question the claimed efficacy of oral ATP at dosages even lower than that used in the present study.

Animal studies and one large cross-sectional study of 752 healthy Chinese men and women suggest that monosodium glutamate (MSG) may be associated with overweight/obesity, and these findings raise public concern over the use of MSG as a flavour enhancer in many commercial foods. The aim of this analysis was to investigate a possible association between MSG intake and obesity, and determine whether a greater MSG intake is associated with a clinically significant weight gain over 5 years. Data from 1282 Chinese men and women who participated in the Jiangsu Nutrition Study were analysed. In the present study, MSG intake and body weight were quantitatively assessed in 2002 and followed up in 2007. MSG intake was not associated with significant weight gain after adjusting for age, sex, multiple lifestyle factors and energy intake. When total glutamate intake was added to the model, an inverse association between MSG intake and 5 % weight gain was found (P = 0·028), but when the model was adjusted for either rice intake or food patterns, this association was abolished. These findings indicate that when other food items or dietary patterns are accounted for, no association exists between MSG intake and weight gain.

High cereal fibre intake is associated with reduced risk for type 2 diabetes, but wheat fibre had little or no effect on glycaemic control or oral glucose tolerance in clinical trials lasting 4–12 weeks. To explain this discrepancy, we hypothesised that colonic adaptation to increased wheat fibre intake takes many months but eventually results in increased SCFA production and glucagon-like peptide-1 (GLP-1) secretion. Thus, the primary objective was to determine the time-course of the effects of increased wheat fibre intake on plasma acetate, butyrate and GLP-1 concentrations in hyperinsulinaemic human subjects over 1 year. Subjects with fasting plasma insulin ≥ 40 pmol/l were randomly assigned by computer to receive either a high-wheat fibre cereal (fibre group; 24 g fibre/d; twenty assigned; six dropped out, fourteen included) or a low-fibre cereal (control group; twenty assigned; six dropped-out, fourteen included) daily for 1 year. Acetate, butyrate and GLP-1 were measured during 8 h metabolic profiles performed every 3 months. There were no differences in body weight in the fibre group compared with the control group. After 9 months baseline-adjusted mean 8 h acetate and butyrate concentrations were higher on the high-fibre than the control cereal (P < 0·05). After 12 months on the high-fibre cereal, baseline-adjusted mean plasma GLP-1 was 1·3 (95 % CI 0·4, 2·2) pmol/l (P < 0·05) higher than at baseline (about 25 % increase) and 1·4 (95 % CI 0·1, 2·7) pmol/l (P < 0·05) higher than after 12 months on control. It is concluded that wheat fibre increased SCFA production and GLP-1 secretion in hyperinsulinaemic humans, but these effects took 9–12 months to develop. Since GLP-1 may increase insulin sensitivity and secretion, these results may provide a mechanism for the epidemiological association between high cereal fibre intake and reduced risk for diabetes.

Re´sume´

Jusqu'il y a 15 ou 20 ans, des nombreux nutritionnistes étaient intéressés principalement dans les effets de l'alimentation sur des paramètres de santé comme la pression sanguine et les concentrations de cholestérol dans le sérum. Ces études ont signifié sans doute une contribution très important à la compréhension actuelle de la relation entre l'alimentation et la santé. Cependant, et pour de nombreuses raisons, il n'y a pas eu beaucoup de monde qui a essayé d'expliquer ces effets au niveau moléculaire. Toutefois, il paraîtra qu'aujourd'hui la tendance a était renversé; un grand nombre de travaux de recherche sont dédié a l'exploration des effets des components de l'alimentation à niveau moléculaire. Ce type de recherche a était fait possible grâce, entre autres facteurs, à l'implémentation de techniques des sciences plus fundamentaux à la recherche dans la nutrition. Ce aussi la disponibilité des séquences du génome qui a accéléré ce changement d'intéret. Les objectives de ce projet sont l'obtention d'une information précis sur les réponses métaboliques et moléculaires des cellules et des tissues (ou même de l'organisme entier) aux components diététiques. Dans ces études, les interactions entre l'alimentation et l'héritage génétique, ainsi qu'entre l'alimentation et des conditions physiologiques et psychologiques doivent aussi etre adressées. Cependant, il n'est pas seulement important l'obtention d'information sur les mécanismes, mais aussi sur les conséquences fonctionnelles pour l'organisme. Une dernière question se pose sur l'usage de cette information pour le développement de tests capable de prescrire des conseils diététiques aux subpopulations spécifiques. Ces questions stimulantes peuvent juste etre abordées à travers d'une approximation intégrée combinant l'expertise de plusieurs disciplines.

The effects of incremental exercise on appetite, energy intake (EI), expenditure (EE) and balance (EB) in lean men and women were examined. Six men (age 29·7 (sd 5·9) years, weight 75·2 (sd 15·3) kg, height 1·75 (sd 0·11) m) and six women (age 24·7 (sd 5·9) years, weight 66·7 (sd 9·10) kg, height 1·70 (sd 0·09) m) were each studied three times during a 16 d protocol, corresponding to no additional exercise (Nex), moderate-intensity exercise (Mex; 1·5–2·0 MJ/d) and high-intensity exercise (Hex; 3·0–4·0 MJ/d) regimens. Subjects were fed to EB during days 1–2, and during days 3–16 they fed ad libitum from a medium-fat diet of constant composition. Daily EE, assessed using the doubly labelled water method, was 9·2, 11·6 and 13·7 MJ/d (P < 0·001; sed 0·45) for the women and 12·2, 14·0 and 16·7 MJ/d (P = 0·007; sed 1·11) for the men on the Nex, Mex and Hex treatments, respectively. EI was 8·3, 8·6 and 9·9 MJ/d (P = 0·118; sed 0·72) for the women and 10·6, 11·6 and 12·0 MJ/d (P = 0·031; sed 0·47) for the men, respectively. On average, subjects compensated for about 30 % of the exercise-induced energy deficit. However, the degree of compensation varied considerably among individuals. The present study captured the initial compensation in EI for exercise-induced energy deficits. Total compensation would take a matter of weeks.

Ingestion of selected nutrients modulates dermal properties. In the present study, two groups of women ingested flaxseed or borage oil for 12 weeks. The control group received a placebo containing medium-chain fatty acids. Dose was 2·2 g total fatty acids/d with α-linolenic acid and linoleic acid as major constituents in the flaxseed oil group; in the borage oil group linoleic and γ-linolenic acid were predominant. In the flaxseed oil group, the contribution of α-linolenic acid to total fatty acids in plasma was significantly increased on weeks 6 and 12, whereas there was an increase in γ-linolenic acid in the borage oil group (P < 0·05). Skin irritation was performed by nicotinate treatment, and changes in skin reddening and blood flow were monitored. Compared to week 0, skin reddening was diminished in both groups; blood flow was also lowered. Skin hydration was significantly increased after 12 weeks of treatment compared to week 0, with flaxseed or borage oil (P < 0·05). Transepidermal water loss was decreased in both oil groups by about 10 % after 6 weeks of supplementation. A further decrease was determined after 12 weeks in the flaxseed oil group. Surface evaluation of living skin revealed that roughness and scaling of the skin were significantly decreased with flaxseed and borage oil comparing week 0 and week 12 (P < 0·05). Except for hydration, none of the parameters was affected in the placebo group. The present data provide evidence that skin properties can be modulated by an intervention with dietary lipids.

Fat is often included in common foods as an emulsion of dispersed oil droplets to enhance the organoleptic quality and stability. The intragastric acid stability of emulsified fat may impact on gastric emptying, satiety and plasma lipid absorption. The aim of the present study was to investigate whether, compared with an acid-unstable emulsion, an acid-stable fat emulsion would empty from the stomach more slowly, cause more rapid plasma lipid absorption and cause greater satiety. Eleven healthy male volunteers received on two separate occasions 500 ml of 15 % (w/w) [13C]palmitate-enriched olive oil-in-water emulsion meals which were either stable or unstable in the acid gastric environment. MRI was used to measure gastric emptying and the intragastric oil fraction of the meals. Blood sampling was used to measure plasma lipids and visual analogue scales were used to assess satiety. The acid-unstable fat emulsion broke and rapidly layered in the stomach. Gastric emptying of meal volume was slower for the acid-stable fat emulsion (P < 0·0001; two-way ANOVA). The rate of energy delivery of fat from the stomach to the duodenum was not different up to t = 110 min. The acid-stable emulsion induced increased fullness (P < 0·05), decreased hunger (P < 0·0002), decreased appetite (P < 0·0001) and increased the concentration of palmitic acid tracer in the chylomicron fraction (P < 0·04). This shows that it is possible to delay gastric emptying and increase satiety by stabilising the intragastric distribution of fat emulsions against the gastric acid environment. This could have implications for the design of novel foods.

The usefulness of the glycaemic index (GI) of a food for practical advice for individuals with diabetes or the general population depends on its reliability, as estimated by intra-class coefficient (ICC), a measure having values between 0 and 1, with values closer to 1 indicating better reliability. We aimed to estimate the ICC of the postprandial blood glucose response to glucose and white bread, instant mashed potato and chickpeas using the incremental area under the curve (iAUC) and the GI of these foods. The iAUC values were determined in twenty healthy individuals on three and four occasions for white bread and glucose, respectively, and for potato and chickpeas on a single occasion. The ICC of the iAUC for white bread and glucose were 0·50 (95 % CI 0·27, 0·73) and 0·49 (95 % CI 0·22, 0·75), respectively. The mean GI of white bread was 81 (95 % CI 74, 90) with a reliability of 0·27 indicating substantial within-person variability. The GI of mashed potato and chickpeas were 87 (95 % CI 76, 101) and 28 (95 % CI 22, 37) respectively with ICC of 0·02 and 0·40.The ICC of the iAUC were moderate and those of the GI fair or poor, indicating the heterogeneous nature of individuals' responses. The unpredictability of individual responses even if they are the result of day-to-day variation places limitations on the clinical usefulness of GI. If the very different GI of potato and chickpeas are estimates of an individual's every-day response to different foods, then the GI of foods may provide an indication of the GI of a long-term diet.

The food industry is playing an increasing role in the development and marketing of new products although little is known regarding the bioavailability of the phytochemicals they contain. Our aim was to assess the effect of the presence of absorption modifiers (milk and iron) on the in vitro bioaccessibility and the serum response in vivo of carotenoids and α-tocopherol from fruit juices. Thirty-two young women participated in a three-period (21 d each) supplementation study with a 2-week wash-out in between. Subjects consumed consecutively 2 × 250 ml/d vitamin C-fortified juices supplied as fruit juice, fruit juice containing milk and fruit juice containing milk and iron. Fasting blood samples were collected before and after each supplementation period. In vitro bioaccessibility of carotenoids and α-tocopherol was assessed by a static digestion model. Vitamin E and carotenoids from both studies were determined by HPLC. In vitro, xanthophyll ester hydrolysis and transference of free xanthophylls and α-tocopherol into the micellar phase were higher in the presence of absorption modifiers. In vivo, consumption of the fruit juices provoked significant increments (within-subject) of α-tocopherol and some carotenoids in serum. Dose-adjusted increments in serum of some carotenoids were higher when subjects consumed juices with milk and milk plus iron, although differences did not reach statistical significance. In conclusion, the presence of milk and milk plus iron do not influence the bioavailability of carotenoids and α-tocopherol from fruit juices in vivo. Our results support the use of in vitro models to assess food-related factors affecting bioavailability of carotenoids and tocopherols from foods.