There is a growing body of evidence implicating the gut 'microbiome' role in overall human health. Bacterial species belonging to the genera Lactobacillus and Bifidobacterium are generally considered to be beneficial and are commonly used in probiotic applications, whereas increases in some genera including Clostridum, Eubacterium and Bacteroides are implicated in negative health outcomes.Dietary polyphenols are bioactive compounds that have been found to increase the numbers of beneficial bacteria and antimicrobial actions against pathogenic bacteria, however most studies have been conducted in animal models or in-vitro colonic models.
The aim of this systematic review was to provide an overview of recent trials on the effect of dietary grape and red wine polyphenols on the gut microbiota in humans. Following PRISMA guidelines, a systematic review was conducted of electronic databases (PubMed, CINAHL, Cochrane Library, Wed of Science and Scopus) to identify human intervention trials examining the effect of grape or wine polyphenols on gut microbiota. Seven trials met the inclusion criteria. One study looked at changes in gut microbiota following the ingestion of de-alcoholised red wine or red wine, and six studies referred to gut microbiota as intermediates in formation of phenolic metabolites.
All studies confirmed that ingested polyphenols from grape and red wine, were modulated by gut microbiota, increasing numbers of polyphenolic metabolites which were found in blood, urine, ileal fluid and faeces. Intake of polyphenols derived from grape and red wine can modulate gut microbiota and contribute to beneficial microbial ecology that can enhance human health benefits. Additionally, grape and red wine polyphenols were modulated by the gut microbiota and there is a potential for a two-way relationship between the gut microbiota and polyphenolic compounds.
Nevertheless, additional research is required to fully understand the complex relationship between gut microbiota and dietary polyphenols before any health claims can be made in relation to human health
AIMS: To investigate associations of life-time hazardous and binge drinking with biomarkers of cardiometabolic health, liver function, cardiovascular disease (CVD) and mortality.
DESIGN: Prospective cohort study with median follow-up time to CVD incidence of 4.5 years.
SETTING: London, UK: civil servants within the Whitehall II Study.
PARTICIPANTS: A total of 4820 drinkers aged 59-83 years with biological measurements during the 2011-12 survey.
MEASUREMENTS: Hazardous drinking was defined as having an AUDIT-C score >/= 5 calculated at each decade of life, forming the following groups: never hazardous drinker, former early (stopping before age 50), former later (stopping after age 50), current hazardous drinker and consistent hazardous drinker (hazardous drinker at each decade of life).
FINDINGS: More than half the sample had been hazardous drinkers at some point during their life-time, comprising former early (< age 50) (19%), former later (>/= age 50) (11%), current (21%) and consistent hazardous drinker (AUDIT-C >/= 5 across life (5%). After adjusting for covariates, waist circumference was larger with more persistent hazardous drinking (e.g. compared with never hazardous drinkers, former early had increased waist circumference by 1.17 cm [95% confidence interval (CI) = 0.25-2.08]; former later by 1.88 cm (CI = 0.77-2.98); current by 2.44 cm (CI = 1.50-3.34) and consistent hazardous drinker by 3.85 cm (CI = 2.23-5.47). Current hazardous drinkers had higher systolic blood pressure (2.44 mmHg, CI = 1.19-3.68) and fatty liver index scores (4.05 mmHg, CI = 2.92-5.18) than never hazardous drinkers. Current hazardous drinkers [hazard ratio (HR) = 2.75, CI = 1.44-5.22) had an elevated risk of stroke, and former later hazardous drinkers had an elevated risk of non-CVD mortality (HR = 1.93, CI = 1.19-3.14) than never hazardous drinkers. Life-time binge drinking was associated with larger waist circumferences and poorer liver function compared with never binge drinkers.
CONCLUSION: Hazardous drinking may increase cardiometabolic risk factors; this is made worse by persistent hazardous drinking throughout life, particularly in relation to weight gain, suggesting benefits of early intervention.
Low-risk thresholds for alcohol use differ across various national guidelines. To assess the novel WHO risk drinking levels in light of alcohol-sensitive common laboratory tests, we analysed biomarkers of liver status, inflammation and lipid profiles from a population-based survey of individuals classified to abstainers and different WHO risk drinking levels defined in terms of mean alcohol consumption per day. The study included 22,327 participants aged 25-74 years from the National FINRISK Study. Data on alcohol use, health status, diet, body weight and lifestyle (smoking, coffee consumption and physical activity) were recorded from structured interviews. Alcohol data from self-reports covering the past 12 months were used to categorize the participants into subgroups of abstainers and WHO risk drinking categories representing low, moderate, high and very high risk drinkers. Serum liver enzymes (GGT, ALT), C-reactive protein (CRP) and lipid profiles were measured using standard laboratory techniques. Alcohol risk category was roughly linearly related with the occurrence of elevated values for GGT, ALT and CRP. Alcohol drinking also significantly influenced the incidence of abnormalities in serum lipids. Significantly higher odds for abnormal GGT, ALT and altered lipid profiles remained in alcohol drinkers even after adjustment for age, waist circumference, physical inactivity, smoking and coffee consumption. A more systematic use of laboratory tests during treatment of individuals classified to WHO risk drinking categories may improve the assessment of alcohol-related health risks. Follow-ups of biomarker responses may also prove to be useful in health interventions aimed at reducing alcohol consumption.
There is a growing body of evidence implicating the gut 'microbiome' role in overall human health. Bacterial species belonging to the genera Lactobacillus and Bifidobacterium are generally considered to be beneficial and are commonly used in probiotic applications, whereas increases in some genera including Clostridum, Eubacterium and Bacteroides are implicated in negative health outcomes. Dietary polyphenols are bioactive compounds that have been found to increase the numbers of beneficial bacteria and antimicrobial actions against pathogenic bacteria, however most studies have been conducted in animal models or in-vitro colonic models. The aim of this systematic review was to provide an overview of recent trials on the effect of dietary grape and red wine polyphenols on the gut microbiota in humans. Following PRISMA guidelines, a systematic review was conducted of electronic databases (PubMed, CINAHL, Cochrane Library, Wed of Science and Scopus) to identify human intervention trials examining the effect of grape or wine polyphenols on gut microbiota. Seven trials met the inclusion criteria. One study looked at changes in gut microbiota following the ingestion of de-alcoholised red wine or red wine, and six studies referred to gut microbiota as intermediates in formation of phenolic metabolites. All studies confirmed that ingested polyphenols from grape and red wine, were modulated by gut microbiota, increasing numbers of polyphenolic metabolites which were found in blood, urine, ileal fluid and faeces. Intake of polyphenols derived from grape and red wine can modulate gut microbiota and contribute to beneficial microbial ecology that can enhance human health benefits. Additionally, grape and red wine polyphenols were modulated by the gut microbiota and there is a potential for a two-way relationship between the gut microbiota and polyphenolic compounds. Nevertheless, additional research is required to fully understand the complex relationship between gut microbiota and dietary polyphenols before any health claims can be made in relation to human health.