Given the enormous amount of Antibiotics that he has taken it is very likely that he has a wicked infestation of candida, and fruits, fruit juices and any concentrated sugars would make things worse. If candida is not present fruits would be great because they are very cleansing and nutritious. But multiple applications of Antibiotics and a worsening of his condition over the course of time that he was on them strongly suggests that candida is present.