Lying about age might not be helpful if your microbiome gives you away, as a new understanding of how our microbiome changes as we age has set the perfect stage for future research on the role microbes play in speeding up or slowing down aging process and influence age-related diseases.
The importance of our microbiota
A team of American, British and Chinese researchers analyzed microbiota data from 8,959 poop, saliva and skin samples from 10 different studies. In total, they examined 4,434 stool samples, 2,550 saliva samples, and 1,975 foot samples , finding that the skin microbiome provided the best prediction of chronological age. It is the largest study to date on microbiome and age, and the results have been collected by the journal mSystems.
The experts were trying to figure out how different microbiomes throughout the body could predict age through how they change as we age, and whether or not those predictions would be accurate. They found that bacteria on the skin, in particular, change so constantly over time that a sample of them can be used to predict a person’s age with a margin of error of 3.8 years. Skin samples provided the most accurate prediction, and stool samples were found to be the least accurate.
Although it sounds like a fun tool, the truth is that it could be very useful for evaluating general health, says Shi Huang, an engineer at the University of California, San Diego and co-author of the study. “Our guess is that if age is a key factor in certain diseases, then the [microbiome] markers that we can identify can also indicate diseases.”
Differences between men and women?
The researchers found gender-specific differences in gut microbiome results, but there were no differences between men and women when it came to skin and oral microbiome results. Despite the diversity of bacteria that live in different places throughout the human body, it also did not make any notable difference whether the skin samples came from the hands or the forehead.
Study limitations
The experts did not include people with health problems in the data set. To see if microbiomes change with age-related disease, scientists must first find out what the “age” of a microbiome is in people with health problems .
What does “microbial age” imply?
Basically it is a substitute for chronological age, on our physical state and health, so you could be 90 years old, but have a microbiome of 50 because we are very healthy, for example.
Thus, it seems that the bacteria in our skin, mouth and intestines are good predictors of our chronological age. We should pay a little more attention to the millions of bacteria that live with us every day.
Curiosity
The margin of error of the algorithm to predict our real age according to the sample:
If the sample is made of leather, the margin of error is 3.8 years
If the sample is oral, the margin of error is 4.5 years
If the sample is fecal, the margin of error is 11.5 years
Reference: Shi Huang, Niina Haiminen, Anna-Paola Carrieri, Rebecca Hu, Lingjing Jiang, Laxmi Parida, Baylee Russell, Celeste Allaband, Amir Zarrinpar, Yoshiki Vázquez-Baeza, Pedro Belda-Ferre, Hongwei Zhou, Ho-Cheol Kim, Austin D. Swafford, Rob Knight, Zhenjiang Zech Xu. Human Skin, Oral, and Gut Microbiomes Predict Chronological Age. mSystems, 2020; 5 (1) DOI: 10.1128 / mSystems.00630-19
