In a recent article published in the Journal of Agricultural and Food Chemistryscientists analyzed the effect of alcoholic and non-alcoholic beer ingestion on the gut microbiota.
Study: Impact of beer and non-alcoholic beer consumption on gut microbiota: a randomized, double-blind, controlled trial. Image Credit: MsMaria/Shutterstock
The fermented extract of malted barley grains, beer, is the most consumed alcoholic beverage in the world. Epidemiological studies have shown that low to moderate beer consumption reduces the risk of cardiovascular disease. These protective benefits of beer are equivalent to those demonstrated with moderate wine consumption.
Nevertheless, the link between alcohol consumption and cancer negates the benefits of alcoholic beverages on diabetes and ischemic heart disease. Thus, despite the numerous preclinical and molecular studies demonstrating the health benefits of fermented alcoholic beverages, it is essential to explore and assess the impacts of dealcoholized and alcoholic beer.
Additionally, like other phenolics, polyphenols in beer can enter the gut, where they may regulate bacterial growth. Live fermentation microbes may also be present in some beers.
The Flemish Gut Flora project showed that beer consumption has a significant impact on the overall composition of the microbiota. Given the role of the gut microbiota in the pathogenesis of cardiovascular disease, obesity, and diabetes, regulating the gut microbiota might be another pathway for regulating the health effects of beer.
About the study
The current research was motivated by the lack of randomized clinical studies examining the effects of non-alcoholic and moderate-alcoholic beer consumption on intermediate measures of cardiovascular risk and gut microbiota. The present pilot investigation aimed to assess how beer, with and without alcohol, affected gut microbiota composition and cardiometabolic markers in healthy men.
In the current double-blind, randomized, two-arm parallel study, researchers recruited 22 healthy men to consume 330 ml, or one bottle, of non-alcoholic beer, i.e. 0.0% v/v, or alcoholic, i.e. 5.2% v/v, beer daily for a four-week follow-up period. Blood and fecal samples were collected before and after the intervention period. In addition, 16S ribosomal ribonucleic acid (16S rRNA) gene sequencing was used to examine the gut microbiota.
Healthy subjects from the Lisbon metropolitan area were recruited through social media advertising. Applicants were asked to visit NOVA Medical School for a physical examination and a quick questionnaire regarding their medical history to assess their eligibility to participate in the research.
Inclusion criteria included healthy men, moderate alcoholics, people aged 18-65, without chronic conditions with significant gastrointestinal consequences, and able and willing to give written informed consent. People with documented cardiovascular disease, diabetes or other relevant metabolic disorders, infectious diseases, use of antibiotics in the previous four weeks or use of laxatives in the last two weeks, and those with a history of alcohol, drug, or other substance abuse was all excluded.
The authors found that drinking non-alcoholic or alcoholic beer daily for four weeks did not increase fat mass or weight. They also found that it did not drastically alter serum cardiometabolic indicators. However, both alcoholic and non-alcoholic beer appear to improve fecal alkaline phosphatase (ALP) function, a measure of gut barrier action. Additionally, they improved the variety of the gut microbiome which has been linked to beneficial health effects.
Phenolic compounds in beer, such as phenolic acids and flavonoids, might contribute to the increase in bacterial heterogeneity observed in the gut microbiota of non-alcoholic and alcoholic beer drinkers. These findings were consistent with other recent research that suggests drinking non-alcoholic beer for 30 days boosts gut microbial α diversity.
The team noted that certain substances, such as yeast, polyphenols and yeast components, can be removed during beer making, especially during beer filtration. As a result, beers high in yeast and polyphenols may have a stronger influence on gut flora than the lager beers used in this investigation.
The results also demonstrated that serum ALP levels drop after four weeks of daily beer consumption, regardless of the alcohol concentration of the beer. Because serum ALP activity was frequently used to assess bone, liver, or heart damage when ALP function was increased, observations of serum ALP activity may not have clinical value.
Overall, the study results revealed that alcoholic or non-alcoholic beer consumption increases gut bacterial variety without affecting body fat mass, body weight, or serum cardiometabolic indicators, making these beverages a promising to stimulate the diversity of the microbiota. Indeed, the present results imply that the effects of beer on gut microbiome regulation were independent of alcohol and may be mediated by the polyphenols present in beer.
Various studies show that alcohol consumption reduces bacterial diversity. The use of alcoholic beer, on the other hand, boosted gut bacterial diversity in the current study. As a result, beer polyphenols appear to have overcome the negative impact of alcohol on gut flora.
Furthermore, the scientists stated that the causative factor for the decrease in serum ALP activity and whether it is related to improved bone, heart or liver function warrants further investigation. Moreover, the impacts of beer on gut microbiota modification and ALP function imply a health benefit that should be sought in a cohort with metabolic disorders.
- Cláudia Marques, Liliana Dinis, Inês Barreiros Mota, Juliana Morais, Shámila Ismael, José B. Pereira-Leal, Joana Cardoso, Pedro Ribeiro, Helena Beato, Mafalda Resende, Christophe Espírito Santo, Ana Paula Cortez, André Rosário, Diogo Pestana, Diana Teixeira, Ana Faria and Conceicao Calhau; Impact of beer and non-alcoholic beer consumption on gut microbiota: randomized, double-blind controlled trial. Journal of Agricultural and Food Chemistry ASAP article, DOI: 10.1021/acs.jafc.2c00587, https://pubs.acs.org/doi/10.1021/acs.jafc.2c00587