I'm not actually advocating using the Antibiotics . I'm having good luck getting rid of the SIBO using vitamin C. I'm going to add the Grapefruit-Seed-Extract as well.
I felt the probiotics were causing a problem, and this sort of confirmed it for me.
Also, there's an important distinction he's making between the Small Bowel and Large Bowel. The two are separated by a valve (ileocecal valve) and are very different environments.
SIBO occurs when bacteria that belong in the Large Bowel overgrow in the small and begin to ferment food before it gets to the Large Bowel.
I agree with your observation about diet. He probably wasn't helping himself by eating oats or soy desserts ;-)