Special bacteria in infants
No, no human (or any other eukaryote lineage) are able to "create bacteria". The story you were told is wrong.

However and interestingly, female parasitoid wasps seem to "create viruses" (Herniou et al. 2013). The viruses are part of the wasp genome (lysogenic phase) and detach (lytic phase) in the ovaries only. The viruses, then infect the caterpillar in which the mother lay its eggs. The viruses ensure to reduce the immune system of the caterpillar in order to protect the wasp egg (and later larvae) and ensure its development to adulthood.