The significance of the human gut microbiome, a vast community of microbes in the gastrointestinal tract, has been known for many years. But it is a complex and varied system that can be affected by many things, like the genes and habits of the host. The effect of diet on the microbiome is recognized, for example, but still poorly understood. New research has now explored the relationship between coffee consumption and the gut microbiome. This work has shown that one type of bacteria called Lawsonibacter asaccharolyticus is found ar much higher levels in the gut microbiomes of coffee drinkers compared to people who do not drink coffee. The findings have been reported in Nature Microbiology.
In this work, the researchers focused on how coffee may affect the gut microbiome because so many people consume coffee, and when they do, it is usually every day.
The investigators assessed health data as well as stool samples, which can reveal some of the microbial species in a person's gut microbiome, and blood samples for about 22,800 residents of the UK and US, and 54,200 people in 211 other study groups in various countries around the world. The scientists focused on how the species in the gut microbiomes of self-reported coffee drinkers compared to the gut microbiomes of those who do not consume the drink.
The L. asaccharolyticus level was the major difference; it was about eight times higher in coffee drinkers. This was true for people who lived all over the world.
The study also replicated some previous findings from other studies: Faecalibacterium and two Alistipes bacteria species were linked to coffee consumption. But the research did not agree with previous work that has linked Bacteroides, Porphyromonas, and Prevotella to coffee intake. The authors noted, however, that some connections may also be population-dependent.
The study authors also showed that coffee can stimulate the growth of L. asaccharolyticus in the lab.
Unfortunately, the significance of this findings is unknown. We still don't know what influence higher L. asaccharolyticus levels may have on human biology, and whether those effects depend on other things. However, it has shown that the consistent intake of one type of beverage can have a very significant impact on the human gut microbiome. The research also determined that certain metabolites, like quinic acid, trigonelline, and some other unknown metabolites, were associated with coffee intake.
Sources: Medical Express, Nature Microbiology