A new study analysing data from 77,000 people worldwide has strengthened evidence that drinking coffee may be beneficial to the gut microbiome by increasing levels of Lawsonibacter asaccharolyticus bacteria.
Previous studies had reported coffee (from more than 150 foods studied) showed the strongest link to gut microbiome composition, and particularly levels of L. asaccharolyticus.
The latest research by an international team of scientists from Italy, the USA and UK – reported in the journal Nature Microbiology – analysed diet and medical data from 22,800 individuals in the US and UK, plus publicly available information from 54,200 people worldwide.
When comparing data from stool samples collected from coffee drinkers and non-drinkers to identify differences in their gut bacteria, the scientists observed several correlations, with the strongest between coffee intake and L. asaccharolyticus. Coffee drinkers had up to 8 times higher levels of the bacteria than non-drinkers – and this pattern was seen across the globe.
While exact health effects of this bacteria remain unproven, researchers believe they could be linked to benefits such as lowering risk of type 2 diabetes and cardiovascular disease, and helping with weight loss.
When comparing ‘heavy’ coffee drinkers (more than 3 cups a day) with ‘light’ drinkers and ‘never’ drinkers (less than 3 cups a month), they noted even the moderate consumption group exhibited 3.4 to 6.4 times greater levels of L. asaccharolyticus than the ‘never’ group – suggesting increasing coffee intake beyond moderate consumption might not have a strong impact on the microbiome and ‘you may not have to drink large amounts of coffee to see changes in your gut microbiome’, summarised medicalnewstoday.com.
The researchers also conducted in vitro experiments, adding caffeinated and decaffeinated coffee to L. asaccharolyticus cultures; both boosted the bacteria’s growth, suggesting ‘compounds in coffee other than caffeine may be responsible for the growth stimulation’.
They further validated the link between L. asaccharolyticus and coffee consumption by correlating per capita coffee intakes with L. asaccharolyticus prevalence in 25 countries, using a re-analysis of thousands of publicly available data sets – adding ‘to the evidence that coffee alters the gut microbiome’s composition, with L. asaccharolyticus particularly responsive to coffee intake’.
US health dietitian Alyssa Simpson (not involved in the study) told medicalnewstoday.com: ‘While we don’t fully understand the mechanism yet, L. asaccharolyticus might play a role in metabolising coffee’s polyphenols like quinic acid into bioactive compounds that contribute to coffee’s known benefits.’
And Professor Thomas Holland at Chicago’s Rush University (not involved in the study) added L. asaccharolyticus is ‘likely associated with coffee’s known health benefits through its involvement in metabolising coffee-derived compounds, such as quinic acid and explained: ‘These metabolites, and other compounds like the polyphenols chlorogenic acid and the catechins (a flavonoid subclass) may influence gut health, inflammation or metabolic processes, potentially contributing to reduced risks of chronic diseases like cardiovascular disease or improved gut microbiome diversity.’
