It's true that we would die if the bacteria disappeard.
Its's also true that bacteria in general would not suffer if we disappeared.
But what he does is comparing one species to a whole domain of organisms.
Tthe domaion is the highest taxonomic rank of organisms. There are as we see it now 3 domains:
- Bacteria
- Archae
- Eucaryotes (cells with nuclei).
We, togehter with all the other animals, plants and fungi belong to the Eucaryotes, all in all there are (one rough estimate) 10 million species in our domain.
Now, estimates like this vary a lot, but one thing seems certain: There are far more bacteria species than eucaryote species. And their properties vary a lot.
If the bacteria that are part of our normal flora in the gutdied out, we would certainly be in trouble. But that is only a tiny, TINY,
TINY fraction of all the bacteria. Most of them are of no importance to us. OTOH some bacteria species would definitely run into problems if we disappeared, that is those for which humans are the only host. And of course, if all eucaryotes disappeared a huge fraction of the bacteria domaioon would die.
So this is what's wrong with the claim. Comparing one species to a group of millions and millions of very different species does not make sense.
a pibbur
PS. I can't here and now come up with a humans only bacterium, but I'm sure they exist (I will take a look). But I know of some viral examples, for instance the smallpox virus. Humans are the only host for that virus, which made it possible to, unlike for instance Ebola which also live in a few animals, eradicate smallpox (no cases since 1977). DS.
EDIT: Two bacteria species that are human specific:
Neisseria meningitidis (one cause of miningitis)
Neisseria gonorrhoeae (cause of gonorrhoea)