So my understanding of intestinal bacteria was that when good bacteria is introduced (in the form of probiotics) it makes its way to the colon, and does not remain in the small gut.
Indeed this was what I've been told from a few doctors, including a Gastroenterologist specialising in gut bacterial dysbiosis.
His protocol for fixing said dysbiosis includes (1) targeted antibiotics and (2) a water based probiotic called
Symprove which has rave ratings over here in the UK. He specified it was important to start both at the same time and claimed he had treated several people in his clinic with gut disorders with this very protocol.
I asked about whether I should be worried about the probiotic adding to my SIBO if not all the small intestine bacteria had been wiped out by the antibiotics, he said no as the Symprove probiotic bacteria wouldn't settle in the small intestine, it would go down to the large intestine, and in fact in doing so it would also help to displace any remaining bacteria residing in the small intestine.