The current study investigated the impact of red wine consumption on the human intestinal microbiota.
The gut microbiota (*) plays a key role in individuals’ physiology and metabolism. A well-balanced gut microbiota composition is essential for a person’s well being. Scientists have recently understood that the make up and overall health of the microbiota as a whole determines whether pathogens in the gut coexist peacefully or can cause disease. Even though specific attention has been paid in recent years to the function of this “biological entity” in the metabolism of polyphenols, less is known about the modulatory capacity of these bioactive compounds on gut microbiota composition.
Recent human studies have shown the importance of diet in shaping the gut microbiota. The human gut microbiota is made up of a collection of cells containing 100 times more genes than the host, it is host-specific and contains heritable components. In general, a high diversity of the fecal microbiota is considered beneficial. Recent studies have shown that by consuming an abundance of „prebiotics“ and „polyphenols“ with the diet, the human gut microbiota can be modulated towards a more health-promoting profile.
Prebiotics represent a specific type of dietary fibre that when fermented, mediates measurable changes within the gut microbiota composition, usually increasing the beneficial bacteria, such as bifidobacteria, in the colon.
The natural phenols and polyphenols in wine include a large group of several hundred chemical compounds that affect the taste, color and mouthfeel of wine. Phenolic acids are largely present in the pulp, anthocyanins and stilbenoids in the skin, and other phenols (catechins, proanthocyanidins and flavonols) in the skin and the seeds. Thus, the proportion of the different phenols in any one wine will vary according to the type of vinification.
Polyphenols have long been studied as the most likely compounds in whole plant foods that are capable of protecting against chronic diet-related diseases. However, such an effect depends on their bioavailability, absorption and metabolism. The gut microbiota is able to transform dietary polyphenols into absorbable biologically active species which can have an impact on health.
Recently, a group of Spanish researchers systematically examined the influence of moderate red wine intake on the colonic microbiota of 15 healthy volunteers. These were classified into high, moderate, and low polyphenol metabolizers (metabotypes) due to their ability to metabolize polyphenols and the results were compared with that of five participants that did not consume any wine. Through DNA sequencing, the composition, diversity and dynamics of their fecal microbiota before and after one month of wine consumption were analysed. After the wine intake, a higher microbial diversity was observed when compared to the control volunteers. However, the inter-individual variability was the strongest and distinguishing feature. The study confirmed the high variability of the microbiota from different individuals and suggested that the responses to the wine intake are influenced by the specific composition of the individual’s intestinal microbiota.
Future studies with a higher number of volunteers are needed to confirm these results.
Barroso E, Muñoz-González I, Jiménez E, et al. Phylogenetic profile of gut microbiota in healthy adults after moderate intake of red wine. Mol Nutr Food Res. 2016 Oct 29. doi: 10.1002/mnfr.201600620. [Epub ahead of print]
For more information about this article, read the scientific abstract here.
(*) Gut microbiota is the name for the microbe population living in the human intestine
The human gut microbiota contains tens of trillions of microorganisms, including at least 1000 different species of known bacteria with more than 3 million genes. Microbiota can, in total, weigh up to 2 kg. One third of our gut microbiota is common to most individuals, while two thirds are specific to each person. The microbiota in each intestine can therefore be considered as an individual’s identity card.
The gut microbiota:
- helps the body to digest certain foods that the stomach and small intestine have not been able to digest;
- helps with the production of some vitamins (B and K);
- helps to combat aggressions from other microorganisms, maintaining the wholeness of the intestinal mucosa;
- plays an important role in the immune system, performing a barrier effect;
- is key to ensuring proper digestive functioning when healthy and balanced
(**) Prebiotics are usually non-digestible carbohydrates, oligosaccharides or short polysaccharides (ie. inulin, oligofructose, galactofructose, etc.). Prebiotics work in partnership with its host’s digestive system to derive energy and carbon from complex plant polysaccharides which would otherwise be lost in faeces.
(***) Polyphenols are mainly phytochemicals found abundantly in natural plant food sources. The most important food sources are fruit and vegetables, green tea, black tea, red wine, coffee, chocolate, olives, and extra virgin olive oil. Herbs and spices, nuts and algae also supply certain polyphenols. Some polyphenols are specific to particular food (ie. flavanones in citrus fruit, isoflavones in soya, phloridzin in apples). Others, such as quercetin, are found in all plant products such as fruit, vegetables, cereals, leguminous plants, tea, and wine.
In general, red wine will be richer in phenols abundant in the skin and seeds, such as anthocyanin, proanthocyanidins and flavonols, whereas the phenols in white wine will essentially originate from the pulp, and these will be the phenolic acids together with lower amounts of catechins and stilbenes. Average total polyphenol content measured by the Folin method is 216 mg/100 ml for red wine and 32 mg/100 ml for white wine. The content of phenols in rosé wine (82 mg/100 ml) is intermediate between that in red and white wines.