Scientists from the Baylor College of Medicine in the United States have shown that frequent coffee consumption leads to a decrease in the risk of developing cardiovascular diseases, diabetes and liver dysfunctions. A summary of the research is available on the American College of Gastroenterology website.
The study involved 34 people who underwent a screening colonoscopy and did not have pathological changes in the colon. Volunteers completed a questionnaire indicating the frequency of coffee consumption. Experts took 97 samples of the mucous membrane from various segments of the patients' intestines and isolated the DNA of the microorganisms that make up the microflora. Then the DNA encoding 16S ribosomal RNA was expanded during the amplification process, that is, additional copies of the isolated genes were created, which facilitated their identification.
Scientists have established the nucleotide sequence of DNA, determining their belonging to different groups of bacteria. They then compared the microbial diversity and frequency of taxa at high (greater than 82.9 milligrams per day) and low (less than 82.9 milligrams) caffeine intake.
It turned out that those who drank a lot of coffee had higher alpha diversity, that is, the diversity within microbial communities, than the rest. Also, the groups of microorganisms in coffee drinkers were significantly different from those that lived in the intestines of participants who consumed little caffeine. The number of Faecalibacterium and Roseburia, which have an anti-inflammatory effect, increased, and the potentially harmful Erysipelatoclostridium and Lachnospiraceae decreased. This relationship was observed regardless of age and nutritional quality.
16S ribosomal RNA (16S rRNA) is one of the main components of ribosomes (synthesizing proteins of cell organelles) in bacteria and archaea. The genes encoding 16S rRNA are used in phylogenetics to determine the evolutionary relationships between different groups of microorganisms due to the low rate of evolution of this DNA region. At present, databases are being created that contain information on microbes containing one or another variant of the 16S rRNA gene.
