An international team of researchers has identified 940 links between mutations in the DNA of gut bacteria and human health, demonstrating a direct correlation between microbial variants and the carrier's age, infohub.kz reports.
Scientists from the University Medical Center Groningen in the Netherlands, working with colleagues from Italy, the United States, Germany, Romania and Tanzania, conducted a large-scale genetic study of the gut microbiome. The findings, published in the journal Nature, showed that individual genetic differences between bacteria of the same species play a critical role in human metabolism and aging, even when the species composition of the microflora remains unchanged.
The authors analyzed metagenomic data from 11,831 stool samples collected from 10,781 people across six independent cohorts. The researchers identified about 12.7 million single-nucleotide variants (SNVs) in 433 bacterial species and compared them with 244 host characteristics and environmental factors. In total, they found 940 independent association signals. Notably, 65.7% of these links were independent of bacterial abundance, and 86.3% of the associations at the level of individual mutations could not be detected through traditional analysis of microbial abundance.
The largest number of genetic links involved human biological age — 99 signals involving 8,117 variants in 42 bacterial species. In particular, five mutations in the sarA_2 gene of the bacterium Faecalibacterium prausnitzii were closely linked to aging: participants carrying this bacterial allele were on average 4.9 years older. Structural analysis showed that the affected protein is involved in the transport of glutathione, an antioxidant that protects cells from oxidative stress. The mutations were also associated with blood pressure, cholesterol levels and body mass index.