A scientific study showed thousands of species of bacteria on women's hands: "They discovered that each student, no matter the gender, had an average of 3,200 bacteria on their hands, coming from some 150 different species. The team was puzzled by the results, as they prove that bacterial diversity is 100-fold higher than previously estimated.
However, the impressive number of bacteria doesn't mean that they appear on all hands. On the contrary, the scientists discovered that only five species were common to all test subjects. Compared to the diversity on their hands, this number is infinitely small. Even the same person’s hands don't have too many bacteria in common. Only 17 percent of species were found on both hands."
Our particulate matter is so overwhelmingly bacterial (200:1) I suppose this isn't so surprising, but it is surprising we're all so DIFFERENT, bacterially speaking, even from one hand to the next; the researches say they should be able to 'fingerprint' individuals by the 'timbre' of their bacterial residue.