The answer is no! They could only do that if there were locations for them to colonize which under normal circumstances does not happen.
The normal colon is made up of biofilms which means that there are no locations for bacteria to implant. Forget it because it cannot happen. It's wishful thinking by anyone who says otherwise.
Bacteria would have to dismantle other biofilms and destroy the bacteria if they were to be able to implant into the colon. This is extremely difficult to do. Just look at the GAPS diet to see how difficult it is to do it. No magic can get around that. Biofilms exist for a reason, you would die without them.
Certain bacteria can cause the break up of biofilms such as bacillus subtilis but even then it is pretty limited.