Latest scientific news 17 June 2015

Wine’s phenolic substances and health – with a little help from our gut “friends”

It seems that wine with its polyphenolic substances can influence the individual gut bacteria which in turn may be associated with significant positive health implications.

Billions of bacteria inhabiting the large intestine form a very complex ecosystem called ‘intestinal microbiome’. Their metabolic capacity is estimated to be approximately 100-fold greater than the capacity of the liver because of the enormous diversity of bacterial species and the high number of genes they contain. Due to this multitude of direct and indirect interactions with the host organism, the intestinal microbiome is closely linked to the health of the host. The microbiome plays a protective role by occupying the surface of the intestine and creating a milieu that prevents the invasion of pathogens. Evidence is increasing that the composition of the intestinal microbiome needs to be considered when researching the influences of eating and drinking habits.

The composition of the human gut ecosystem is influenced by multiple and diverse factors, such as age, origin, environment, the application of antibiotics and dietary habits. Thus, individuals show their own unique profile of microbial species, which can be compared to a fingerprint. One role, if not the most crucial role, is the influence on the metabolism of chemical compounds found in foods. Plants contain large amounts of secondary plant metabolites. These substances, mainly polyphenols, show important properties such as anti-inflammatory, antimicrobial, anti-oxidant and anti-cancer activity. However, it has become evident that the biological activity and the health effects derived from the consumption of polyphenol-rich foods, such as red wine, are mainly due to the phenolic metabolites formed in the gastrointestinal tract by gut bacteria rather than the original forms present in foods. Wine polyphenols are poorly absorbed in the small intestine, so they can reach the colon. There, the polyphenols are catabolized by the gut microbiome. The impact of these polyphenols on the host’s health greatly depends on the individual’s unique microbial composition and on the ability of the bacteria to transform these specific components via various enzymes (esterase, glucosidase, demethylation, dehydroxylation and decarboxylation activities).

Variations in dietary patterns appear to be a key contributing factor to the diversity of the human gut microbiome. Non-digestible carbohydrates (dietary fiber and resistant starches) are primary substrates that escape digestion in the small intestine in appreciable amounts. These substrates subsequently become available for the gut microbiota for colonic fermentation. Depending on the quality and quantity of ingested fermentable carbohydrates, the diet can alter the composition of the gut microbiome. A diet that is either selective or defective with respect to its nutrient content will cause a disruption of the delicate balance between the host and its intestinal microbiome, leading to diet-related “dysbiosis”. Such a situation may subsequently favor the overgrowth of opportunistic pathogens and weaken the host defense against infection and chronic inflammation, possibly via alterations in mucosal immunity. On the other hand, dietary patterns that favorably alter the gut microbiota, specifically those that emphasize plant-based foods, may have significant positive implications to human health.

Since diet can influence the microbiome, and gut bacteria can influence the fate of polyphenolic substances ingested with food and beverages as well as the wine’s ability to influence the gut microbiota with its phenolic substances, it seems crucial to do much more research in this field to understand the role of wine consumption on our health.

  1. Duda-Chodak A, Tarko T, Satora P, et al. Interaction of dietary compounds, especially polyphenols, with the intestinal microbiota: a review. Eur J Nutr 2015;54(3):325-41.
    For more information about this article, read the scientific abstract here.
  2. Jimenez-Giron A, Munoz-Gonzalez I, Martinlvarez PJ, et al. Towards the fecal metabolome derived from moderate red wine intake. Metabolites 2014;4(4):1101-18.
    For more information about this article, read the scientific abstract here.
  3. Wang D, Ho L, Faith J, et al. Role of intestinal microbiota in the generation of polyphenol-derived phenolic acid mediated attenuation of Alzheimer’s disease beta-amyloid oligomerization. Mol Nutr Food Res 2015.
    For more information about this article, read the scientific abstract here.