Wait, what is your microbiome? Take a deep breath: It’s the trillions of microbes—think bacteria, fungi, protozoa, and viruses—that live on and in you. (These are the reasons why bacteria is good for you!) Your microbiome’s makeup can shift around based on your diet, environment, or the people in your life. But, much like your fingerprint, your microbiome is one-of-a-kind, and it reveals quite a lot about you.
Your biological sex
In a new study, Canadian researchers swabbed skin samples from 17 different sites on the bodies of 10 couples and discovered that the skin microbiomes on the inner thigh were the most accurate predictors of biological sex. The inner thigh swabs accurately predicted a person’s gender 100 percent of the time, compared to the 80 percent accuracy rate of samples taken from other areas of the body. The research team suspects it may be because the proximity of the genitals influences a person’s microbiome in that area.