Exactly! Our microbiomes are the new frontier of health for all sorts of things, obesity being number one for the general western population.
It's only a matter of time, and IP law, that engineered bacteria will be sold as designer probiotics to counter all sorts of maladies. Could we easily create a grassroots organization to distribute colon flora? Sure! But the fat, sterile westerners will say "Ew, gross!", but happily pay for Monsanto Microbiome Enhancement Plus for a premium. (it's a fictional drug to counter the bacterial imbalance created by eating processed, industrialized food.)
Just as the finding of lead in our environment is bad for humans, perhaps so will antibiotics from medicines to soaps, along with polymers such as BPA (commonly found in most thermal paper receipts that people handle on a daily basis), be found to cause harm to our microbiome.
If you count cells in the human body, there are more bacterial cells than human cells; of course the human cells are much larger, but human individuals are complex organisms living with lots of other living "things".