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Alpha-Linolenic and Linoleic Fatty Acids in the Vegan Diet: Do They Require Dietary Reference Intake/Adequate Intake Special Consideration?
Burns-Whitmore, B, Froyen, E, Heskey, C, Parker, T, San Pablo, G
Nutrients. 2019;11(10)
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Fish and seafood are good sources of long-chain omega-3 fatty acids, like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). A vegan diet does not include animal-sourced foods and is therefore void of EPA and DHA, unless algae-derived omega-3 supplements are consumed. Thus, vegans rely on the body's own production of long-chain fatty acids from plant-derived alpha-linolenic acid (ALA). However, adequate conversion can have several limitations. Vegan diets are generally rich in linoleic acid (LA), an omega-6 fatty acid, which in high levels can impede the conversion of ALA to EPA and DHA. Furthermore, the efficiency of conversion is influenced by gender, age or health conditions like obesity. This review sought to discuss whether vegans require special dietary recommendations for fatty acids and what these suggestions could be. Most studies assessing biological indicators of fatty acid status showed that vegans had lower levels of EPA and DHA compared to omnivores. Thus, the authors concluded that special consideration should be given to ALA and LA intake in vegan diets. In the absence of a set recommendation for a fatty acid ratio, a ratio of 4:1 (omega-6:omega-3) was proposed for vegans and omnivores. A reduction in LA and an increased intake of ALA of 2.2–4.4 g/day (or 1.1 g/day/1000 Kcals) was suggested to achieve such. This article is a useful guide when considering adequate fatty acid balance and omega-3 conversion for individuals following a vegan diet.
Abstract
Good sources of the long-chain n-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) include cold-water fish and seafood; however, vegan diets (VGNs) do not include animal-origin foods. Typically, US omnivores obtain enough dietary EPA and DHA, but unless VGNs consume algal n-3 supplements, they rely on endogenous production of long-chain fatty acids. VGN diets have several possible concerns: (1) VGNs have high intakes of linoleic acid (LA) as compared to omnivore/non-vegetarian diets. (2) High intakes of LA competitively interfere with the endogenous conversion of alpha-linolenic acid (ALA) to EPA and DHA. (3) High somatic levels of LA/low ALA indicate a decreased ALA conversion to EPA and DHA. (4) Some, not all VGNs meet the Dietary Reference Intake Adequate Intake (DRI-AI) for dietary ALA and (5) VGN diets are high in fiber, which possibly interferes with fat absorption. Consequently, health professionals and Registered Dietitians/Registered Dietitian Nutritionists working with VGNs need specific essential fatty acid diet guidelines. The purpose of this review was: (1) to suggest that VGNs have a DRI-AI Special Consideration requirement for ALA and LA based on VGN dietary and biochemical indicators of status and (2) to provide suggestions to ensure that VGNs receive adequate intakes of LA and ALA.
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2.
The Effects of Vegetarian and Vegan Diets on Gut Microbiota.
Tomova, A, Bukovsky, I, Rembert, E, Yonas, W, Alwarith, J, Barnard, ND, Kahleova, H
Frontiers in nutrition. 2019;6:47
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The difference in gut microbiota composition between individuals following vegan or vegetarian diets and those following omnivorous diets is well documented. A plant-based diet appears to be beneficial for human health by promoting the development of more diverse and stable microbial systems. This diversity appears to have an important association with BMI, obesity, and arterial compliance. This review highlights the effects of different diets, particularly plant-based diets, on the gut microbiota composition and production of microbial metabolites affecting the host health. The ratio between Bacteroidetes and Firmicutes is discussed and how different diets can change it. It explains how diet can affect the three main enterotypes: Prevotella, Bacteroides, and Ruminococcus. The food components proteins, carbohydrates, fats and polyphenols are discussed and how they influence gut microbiota. Up to date knowledge suggests that a plant-based diet may be an effective way to promote a diverse ecosystem of beneficial microbes that support overall health. However, due to the complexity and inter-individual differences, further research is required to fully characterize the interactions between diet, the microbiome, and health outcomes.
Abstract
The difference in gut microbiota composition between individuals following vegan or vegetarian diets and those following omnivorous diets is well documented. A plant-based diet appears to be beneficial for human health by promoting the development of more diverse and stable microbial systems. Additionally, vegans and vegetarians have significantly higher counts of certain Bacteroidetes-related operational taxonomic units compared to omnivores. Fibers (that is, non-digestible carbohydrates, found exclusively in plants) most consistently increase lactic acid bacteria, such as Ruminococcus, E. rectale, and Roseburia, and reduce Clostridium and Enterococcus species. Polyphenols, also abundant in plant foods, increase Bifidobacterium and Lactobacillus, which provide anti-pathogenic and anti-inflammatory effects and cardiovascular protection. High fiber intake also encourages the growth of species that ferment fiber into metabolites as short-chain fatty acids (SCFAs), including acetate, propionate, and butyrate. The positive health effects of SCFAs are myriad, including improved immunity against pathogens, blood-brain barrier integrity, provision of energy substrates, and regulation of critical functions of the intestine. In conclusion, the available literature suggests that a vegetarian/vegan diet is effective in promoting a diverse ecosystem of beneficial bacteria to support both human gut microbiome and overall health. This review will focus on effects of different diets and nutrient contents, particularly plant-based diets, on the gut microbiota composition and production of microbial metabolites affecting the host health.
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A Review of Dietary (Phyto)Nutrients for Glutathione Support.
Minich, DM, Brown, BI
Nutrients. 2019;11(9)
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Glutathione is made up of 3 amino acids (cysteine, glutamic acid and glycine) and plays important roles in the body, including oxidative stress reduction, supporting the immune system and contributing to detoxification processes. Evidence suggests that it is an important marker and target for treatment in many chronic, age-related diseases. This review article explores the evidence of nutritional strategies to improve glutathione status. The authors examine the evidence for supplementation of the precursors of glutathione as well as with various forms of supplemental glutathione itself, and the impacts on glutathione status and clinical impacts. Crucially, the review article provides information on dietary sources of precursors of glutathione and glutathione itself, which will provide Nutrition Practitioners with compelling information for use in clinic. Lean protein, brassica vegetables, polyphenol-rich fruits and vegetables, green tea, herbs and spices and omega-3 rich foods are all discussed in detail.
Abstract
Glutathione is a tripeptide that plays a pivotal role in critical physiological processes resulting in effects relevant to diverse disease pathophysiology such as maintenance of redox balance, reduction of oxidative stress, enhancement of metabolic detoxification, and regulation of immune system function. The diverse roles of glutathione in physiology are relevant to a considerable body of evidence suggesting that glutathione status may be an important biomarker and treatment target in various chronic, age-related diseases. Yet, proper personalized balance in the individual is key as well as a better understanding of antioxidants and redox balance. Optimizing glutathione levels has been proposed as a strategy for health promotion and disease prevention, although clear, causal relationships between glutathione status and disease risk or treatment remain to be clarified. Nonetheless, human clinical research suggests that nutritional interventions, including amino acids, vitamins, minerals, phytochemicals, and foods can have important effects on circulating glutathione which may translate to clinical benefit. Importantly, genetic variation is a modifier of glutathione status and influences response to nutritional factors that impact glutathione levels. This narrative review explores clinical evidence for nutritional strategies that could be used to improve glutathione status.
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Role of Probiotics in Non-alcoholic Fatty Liver Disease: Does Gut Microbiota Matter?
Xie, C, Halegoua-DeMarzio, D
Nutrients. 2019;11(11)
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Non-alcoholic fatty liver disease (NAFLD) is characterised by an excessive accumulation of fat in the liver tissue, without excessive alcohol consumption, and appears to be related to metabolic syndrome. It is thought to have a prevalence of 25% globally and there are no pharmacological treatments available. This review discusses the connection between the gut microbiota (GM) and NAFLD. Various mechanisms by which the GM may be involved in the development of NAFLD are discussed. As probiotics and prebiotics can normalise GM and reverse dysbiosis their use may benefit patients with NAFLD. This has been confirmed in animal models. The authors review 26 randomised controlled trials (RCTs) of probiotics and/or prebiotics in the treatment of NAFLD which evaluate biochemical markers, as well as five meta-analyses, and found that overall there is strong evidence that probiotics and/or prebiotics can lower ALT and AST (markers of NAFLD), although results for other biochemical markers were mixed. They also reviewed RCTs assessing NAFLD by imaging and histological means, and again found benefits from probiotic and/or prebiotic supplementation.
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the hepatic consequence of metabolic syndrome, which often also includes obesity, diabetes, and dyslipidemia. The connection between gut microbiota (GM) and NAFLD has attracted significant attention in recent years. Data has shown that GM affects hepatic lipid metabolism and influences the balance between pro/anti-inflammatory effectors in the liver. Although studies reveal the association between GM dysbiosis and NAFLD, decoding the mechanisms of gut dysbiosis resulting in NAFLD remains challenging. The potential pathophysiology that links GM dysbiosis to NAFLD can be summarized as: (1) disrupting the balance between energy harvest and expenditure, (2) promoting hepatic inflammation (impairing intestinal integrity, facilitating endotoxemia, and initiating inflammatory cascades with cytokines releasing), and (3) altered biochemistry metabolism and GM-related metabolites (i.e., bile acid, short-chain fatty acids, aromatic amino acid derivatives, branched-chain amino acids, choline, ethanol). Due to the hypothesis that probiotics/synbiotics could normalize GM and reverse dysbiosis, there have been efforts to investigate the therapeutic effect of probiotics/synbiotics in patients with NAFLD. Recent randomized clinical trials suggest that probiotics/synbiotics could improve transaminases, hepatic steatosis, and reduce hepatic inflammation. Despite these promising results, future studies are necessary to understand the full role GM plays in NAFLD development and progression. Additionally, further data is needed to unravel probiotics/synbiotics efficacy, safety, and sustainability as a novel pharmacologic approaches to NAFLD.
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Medical and Dietary Uses of N-Acetylcysteine.
Šalamon, Š, Kramar, B, Marolt, TP, Poljšak, B, Milisav, I
Antioxidants (Basel, Switzerland). 2019;8(5)
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N-Acetylcysteine (NAC) is an antioxidant naturally found in plants of the Allium species such as onions. As well as having antioxidant and anti-inflammatory properties, it is also needed to make glutathione which is an important antioxidant in cells. NAC has been used as a drug since the 1960s and is a popular dietary supplement. NAC is considered safe but the results of clinical trials are controversial or incomplete. This aim of this review is to provide a balanced view of further uses of NAC as a dietary supplement. It discusses the antioxidant properties in relation to conditions such as heart disease, diabetes and ageing; its medical uses, in the complementary treatment of cancer, as a sports supplement and as an anti-aging supplement. More information is needed on NAC and further clinical trials looking at its use in neurodegenerative diseases, addiction, and mental health disorders are underway. This may be relevant to the supplement users and may also help people suffering from chronic degenerative conditions.
Abstract
N-acetylcysteine (NAC), a plant antioxidant naturally found in onion, is a precursor to glutathione. It has been used as a drug since the 1960s and is listed on the World Health Organization (WHO) Model List of Essential Medicines as an antidote in poisonings. There are numerous other uses or proposed uses in medicine that are still in preclinical and clinical investigations. NAC is also used in food supplements and cosmetics. Despite its abundant use, there are projections that the NAC global market will grow in the next five years; therefore, the purpose of this work is to provide a balanced view of further uses of NAC as a dietary supplement. Although NAC is considered a safe substance, the results among clinical trials are sometimes controversial or incomplete, like for many other antioxidants. More clinical trials are underway that will improve our understanding of NAC applicability.
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Sorting out the Value of Cruciferous Sprouts as Sources of Bioactive Compounds for Nutrition and Health.
Abellán, Á, Domínguez-Perles, R, Moreno, DA, García-Viguera, C
Nutrients. 2019;11(2)
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Vegetable sprouts are naturally rich in nutrients and other beneficial compounds. The sprouts of cruciferous vegetables, such as broccoli, kale, radish and pak choi, stand out due to their high contents of glucosinolates and phenolic compounds. The aim of this review was to compile and update the available knowledge on the production, nutritional composition, and health benefits of cruciferous sprouts. A number of studies have found that compounds found in cruciferous sprouts have anti-cancer, anti-inflammatory, and antioxidant capacities. Consumption of cruciferous sprouts contributes to healthy glucose, insulin and fat levels in the blood, and may be beneficial for the treatment of some metabolic disorders, such as type 2 diabetes. There is evidence that compounds in cruciferous sprouts are a useful tool for enhancing phase II enzymes in the liver, and benefit levels of interleukine-6, C-reactive protein, and tumour necrosis factor-α, and inhibition of NF-κB, among others. The active compounds in these sprouts have an influence on several cardiovascular processes, potentially reducing the risk of several diseases. The lack of consistency between studies with regard to sampling schedules, doses, sample size, etc. means that it is not possible at this time to state the effective dose of sprouts or their active compounds needed in order to achieve health benefits. Further research is needed in this area.
Abstract
Edible sprouts with germinating seeds of a few days of age are naturally rich in nutrients and other bioactive compounds. Among them, the cruciferous (Brassicaceae) sprouts stand out due to their high contents of glucosinolates (GLSs) and phenolic compounds. In order to obtain sprouts enriched in these phytochemicals, elicitation is being increasing used as a sustainable practice. Besides, the evidence regarding the bioavailability and the biological activity of these compounds after their dietary intake has also attracted growing interest in recent years, supporting the intake of the natural food instead of enriched ingredients or extracts. Also, there is a growing interest regarding their uses, consumption, and applications for health and wellbeing, in different industrial sectors. In this context, the present review aims to compile and update the available knowledge on the fundamental aspects of production, enrichment in composition, and the benefits upon consumption of diverse edible cruciferous sprouts, which are sources of phenolic compounds and glucosinolates, as well as the evidence on their biological actions in diverse pathophysiological situations and the molecular pathways involved.
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Effects of Drugs and Excipients on Hydration Status.
Puga, AM, Lopez-Oliva, S, Trives, C, Partearroyo, T, Varela-Moreiras, G
Nutrients. 2019;11(3)
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A person’s hydration status is determined by water balance, which is inferred as ‘the difference between water input and water output’. Water balance should ideally remain within a tight range allowing for optimal functioning of bodily processes. Many substances as well as those in foods and fluids can affect a person’s hydration status, including several medications and their excipients (an excipient is a substance added to an active ingredient to stabilise the chemicals within the medication, often known as bulking agents or fillers). Fluctuations in hydration status can result from taking certain medications which induce possible side effects, such as diarrhoea/constipation, altered appetite, temperature dysregulation etc. The aim of this review was to analyse previous research carried out investigating the effects of widely prescribed medications and their excipients known to alter hydration status. The authors concluded that several medications and their excipients play a significant role in hydration status and this should be considered by health professionals, especially when prescribing medications to vulnerable patients.
Abstract
Despite being the most essential nutrient, water is commonly forgotten in the fields of pharmacy and nutrition. Hydration status is determined by water balance (the difference between water input and output). Hypohydration or negative water balance is affected by numerous factors, either internal (i.e., a lack of thirst sensation) or external (e.g., polypharmacy or chronic consumption of certain drugs). However, to date, research on the interaction between hydration status and drugs/excipients has been scarce. Drugs may trigger the appearance of hypohydration by means of the increase of water elimination through either diarrhea, urine or sweat; a decrease in thirst sensation or appetite; or the alteration of central thermoregulation. On the other hand, pharmaceutical excipients induce alterations in hydration status by decreasing the gastrointestinal transit time or increasing the gastrointestinal tract rate or intestinal permeability. In the present review, we evaluate studies that focus on the effects of drugs/excipients on hydration status. These studies support the aim of monitoring the hydration status in patients, mainly in those population segments with a higher risk, to avoid complications and associated pathologies, which are key axes in both pharmaceutical care and the field of nutrition.
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Impact of Nutritional Changes on Nonalcoholic Fatty Liver Disease.
Perdomo, CM, Frühbeck, G, Escalada, J
Nutrients. 2019;11(3)
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The major established risk factors for non-alcoholic fatty liver disease (NAFLD) include obesity, insulin resistance and dyslipidaemia. This in-depth review looks at research into the effects of macronutrient composition and dietary patterns on NAFLD. Lifestyle modifications leading to weight reduction and/or increased physical activity consistently showed improvements in NAFLD. Based on the reviewed studies, the authors recommend a diet that includes whole grains, mono-unsaturated fatty acids (in moderation), omega 3 poly-unsaturated fatty acids, vegetable protein and fibre, whilst avoiding simple sugars, trans and saturated fats, and red and processed meats. The effects of these macronutrients were independent of weight loss. There was insufficient evidence for a beneficial role of probiotics, resveratrol, coffee, taurine and choline. The Western dietary pattern, characterised by high intakes of saturated fats and fructose, was associated with an increased risk of NAFLD. The Mediterranean Diet (MD), characterised by a high consumption of plant-based foods (whole grains, cereals, seeds, nuts, legumes, vegetables and fruits), moderate consumption of protein-source foods (fish, seafood, and poultry), low to moderate red wine consumption, low consumption of meat, milk and dairy products, was thought to be beneficial. The “Dietary Approach to Stop Hypertension” (DASH) diet, with an emphasis on low intake of sodium, total fat, saturated fat, cholesterol and added sugars, was also found to be beneficial. The effects of low carbohydrate diets were unclear, as any benefits may be due to the associated weight loss rather than the macronutrient composition per se. The authors point out that much of the research is observational (i.e. epidemiological) and that more prospective clinical trials are needed.
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a major global health threat due to its growing incidence and prevalence. It is becoming the leading cause of liver disease in addition to its strong association with cardio-metabolic disease. Therefore, its prevention and treatment are of strong public interest. Therapeutic approaches emphasize lifestyle modifications including physical activity and the adoption of healthy eating habits that intend to mainly control body weight and cardio-metabolic risk factors associated with the metabolic syndrome. Lifestyle interventions may be reinforced by pharmacological treatment in advanced stages, though there is still no registered drug for the specific treatment of NAFLD. The purpose of this review is to assess the evidence available regarding the impact of dietary recommendations against NAFLD, highlighting the effect of macronutrient diet composition and dietary patterns in the management of NAFLD.
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Metabolic Syndrome Features: Is There a Modulation Role by Mineral Water Consumption? A Review.
Costa-Vieira, D, Monteiro, R, Martins, MJ
Nutrients. 2019;11(5)
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Metabolic syndrome, defined as having high blood pressure, triglycerides, blood glucose and being obese, is becoming an increasing worldwide health problem. It’s considered to be a result of modern-day life styles and there is no effective cure other than diet and life style interventions. This review paper looks at the mineral content and the alkalising effects of mineral water when consumed by participants with metabolic syndrome. The minerals within mineral water are thought to be more readily absorbed in the body than when consumed in foods and since Westernised diets are low in mineral content and high in acidity, consuming mineral water could help counteract mineral deficiencies and help to balance pH in those with metabolic syndrome. 20 studies, both animal and human, were selected for evaluation of the effect of mineral water on blood pressure, lipid profile, blood glucose and waist circumference. The authors conclude that mineral water is indeed beneficial to those with metabolic syndrome and can help counteract mineral deficiencies and balance pH. However, it is unclear whether mineral water in high quantities would be detrimental to a person with adequate mineral status and a pH within optimal range. Further studies are needed.
Abstract
Metabolic syndrome (MetSyn) promotes, among others, the development of atherosclerotic cardiovascular disease and diabetes. Its prevalence increases with age, highlighting the relevance of promoting precocious MetSyn primary prevention and treatment with easy-to-implement lifestyle interventions. MetSyn features modulation through mineral water consumption was reviewed on Pubmed, Scopus and Google Scholar databases, using the following keywords: metabolic syndrome, hypertension, blood pressure (BP), cholesterol, triglycerides, apolipoprotein, chylomicron, very low-density lipoprotein, low-density lipoprotein, high-density lipoprotein (HDL), glucose, insulin, body weight, body mass index, waist circumference (WC), obesity and mineral(-rich) water. Twenty studies were selected: 12 evaluated BP, 13 assessed total-triglycerides and/or HDL-cholesterol, 10 analysed glucose and/or 3 measured WC. Mineral waters were tested in diverse protocols regarding type and composition of water, amount consumed, diet and type and duration of the study. Human and animal studies were performed in populations with different sizes and characteristics. Distinct sets of five studies showed beneficial effects upon BP, total-triglycerides, HDL-cholesterol and glucose. WC modulation was not reported. Minerals/elements and active ions/molecules present in mineral waters (and their pH) are crucial to counterbalance their inadequate intake and body status as well as metabolic dysfunction and increased diet-induced acid-load observed in MetSyn. Study characteristics and molecular/physiologic mechanisms that could explain the different effects observed are discussed. Further studies are warranted for determining the mechanisms involved in the putative protective action of mineral water consumption against MetSyn features.
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Potential Factors Influencing the Effects of Anthocyanins on Blood Pressure Regulation in Humans: A Review.
Vendrame, S, Klimis-Zacas, D
Nutrients. 2019;11(6)
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Anthocyanins (ACNs) are plant compounds belonging to the flavonoid group of polyphenols and are naturally occurring in a number of foods. They are responsible for the red, blue and purple pigmentation within plant foods, such as blueberries and raspberries and are known to contain therapeutic compounds. Several studies have investigated the anti-inflammatory, antioxidant and blood pressure modulation properties within ACNs, however, results for blood pressure modulation, unlike those for anti-inflammatory and antioxidant properties have been mixed and less consistent. This paper reviews 66 human intervention trials exploring the effects of various forms of ACNs, like whole berries, concentrates and freeze-dried powders in order to identify the singular variables related to blood pressure modulation in order to further investigate. Having looked at a number of variables within the trials, researchers concluded that ACNs do in fact contain blood pressure lowering properties, but further research into varying factors including dose effect, synergistic effects, absorption and metabolism and the functionality of the individuals gut microbiota is needed to clarify results further.
Abstract
Dietary intake of anthocyanins (ACNs) is associated with a reduced risk of cardiovascular and coronary heart disease. While the anti-inflammatory, antioxidant, and lipid-lowering effects of ACN consumption have been consistently reported, their effect(s) on blood pressure regulation is less consistent and results from human studies are mixed. The objective of this review is attempting to identify potential patterns which may explain the variability in results related to blood pressure. To do so, we review 66 human intervention trials testing the effects on blood pressure of purified ACN or ACN-rich extracts, or whole berries, berry juices, powders, purees and whole phenolic extracts, from berries that are rich in ACN and have ACNs as predominant bioactives. Several factors appear to be involved on the mixed results reported. In particular, the baseline characteristics of the population in terms of blood pressure and total flavonoid intake, the dose and duration of the intervention, the differential effects of individual ACN and their synergistic effects with other phytochemicals, the ACN content and bioavailability from the food matrix, and individual differences in ACN absorption and metabolism related to genotype and microbiota enterotypes.