You might research how L. Reuteri bacteria can help SIBO. The Lifeway kefir contains this bacteria.
Also, you might look at probiotics that contain Rhodopseudomonas palustris. This bacteria is able to entrain bad bacteria into becoming good bacteria, that is bacteria that normally create toxic metabolites will start creating nutrients and antioxidants instead. Some products that contain R. palustris are SCD Essential Probiotics and TeraGanix Pro EM-1. I recommend the SCD product over the Teraganix, but both will work.