There are billions of bacteria all in, around, and all over you. They prevent diseases, regulate digestion, and everything in between. Researcher Alex Zhavoronkov and his colleagues at InSilico Medicine in Maryland c study and examine whether their predictions that “microbiomes are aging clocks” were true.

To start their study, Alex and his team gathered 3600 samples of gut bacteria from 1165 healthy individuals from around the world, ranging from three age samples. A third of the participants were aged 20 to 39, another third were aged 40 to 59, and the last third were from people aged 60 to 90. They then used machine learning. This means they trained a computer program on “95 different species of bacteria from 90% of the samples, along with the ages of the people they had come from. Then, they asked the algorithm to predict the ages of the people who provided the remaining 10%”. Their program ended up being successful in that 39 bacteria of the 95 were successful in predicting someone’s age within four years.

When researching the certain biomes, Eubacterium hallii-which is important for intestines and metabolisms-became more abundant with age. They also noticed bacteria like Bacteroides vulgatus decreased with age. Alex and his team predict that the different bacteria found may help in detecting peoples’ age.

If validated, the “microbiome aging clock” they created can have many positive effects. It could be used to compare healthy people with those who have diseases. It can test how fast someone is aging and test if any antibiotics, probiotics, diet, or alcohol affect aging. It could help test new treatments or medicine and see if it would have any effect on the aging process. However, challenges may arise. One may include distinguishing whether the different microbes come from age or come from “markedly different populations”. Researcher Robin Knight states, “ it’s also not known whether changes in the microbiome cause people to age more rapidly, or whether the changes are simply a side effect of aging”. It is not yet guaranteed how the aging-clock machine will turn out but if it ends up being successful, many would consider for it to be life-changing.