The gut should be acidic to support lactobacteria colonization. What do think L. Acidophilus means? Acid loving bacteria.
Candida hates an acid gut and thrives in an alkaline gut. In fact, when candida overgrowth occurs the ph of the gut changes from acidic to alkaline. That's one of the major reasons that candida can be so hard to cure. That's why candida can rarely be cured by lactobacteria probiotics alone. The swallowed lactobacteria hit the alkaline gut and they, die, die, die.