Untangling the two-way relationship between red wine polyphenols and gut microbiota 

A study published in the Journal Gastroenterology looks at the current evidence on the relationship between red wine polyphenols and gut microbiota.
The authors state that ‘It is without doubt that modifications of gut microbiota are at the intersection between dietary intake and beneficial health outcomes, and understanding the benefits of red wine polyphenols on gut microbiota remains presented with challenges and controversies. Some of these include the diversity of consumed wines and variation in their polyphenolic content that is influenced by variety of factors. Even with doses that are exceeding physiologically relevant concentrations, evidence of cardiometabolic effects is inconclusive. Therefore, whether moderate to high dosages will exhibit beneficial health effects without negative implications on gut barrier integrity and gut microbiota is still unknown. This might be further elucidated with technological and research advances in the ‘-omics’ areas where red wine polyphenols by-products might be investigated from the population perspective’.
The authors conclude that ‘The influence of red wine polyphenols on gut microbiota is becoming widely recognised; however, further research of low to moderate consumption of red wine polyphenols over more extended periods is necessary to elucidate the impact of various factors, including overall diet composition. Red wine consumption should always be studied in the context of the overall dietary habits of individuals to take into account residual confounding and bias. The majority of observational studies fail to do this adequately; and thus, results from large- scale clinical trials are needed in order to establish a cause and effect relationship between red wine polyphenols and gut microbiota. As high consumption of alcohol is still associated with multiple adverse health effects, it remains to be seen whether long-term trials of red wine can be safely managed in an ethically responsible manner’.