From what I know, adding more probiotics would be counterindicated with SIBO. Read Dr. Galland's material on his website mdheal.org where he covers much of this material. You would be triggering more immune reactions by adding probiotics or anything that may be feeding the infection. By stimulating immunity, you will set off all kinds of other issues including neurological, endocrine and other things.
SIBO as you know is an overgrowth of bacteria in the gut, some have indicated that
a deficiency of digestive enzymes can allow the bacteria to grow, I would think that by adding anti bacterial things is what you want.
I would watch the types of foods you are consuming as well as supplements that may be encouraging the growth of the unwanted bacteria. The could be feeding on sugars, or high sulfur content etc, also some supplements may be helping them. The only way to unravel this is by trial and error.