Yes, stomach acids may kill most resident strains of probiotics taken orally because they are supposed to reside in the colon and should not have to go through the stomach and digestive process. Also, Lactobacillus acidophilus can only function in an acid medium. Acidophilus literally means 'acid-loving'. Many of us have alkaline colons, so this is often a major factor in the failure of acidophilus products. The colon should ideally be slightly acidic to support the proliferation of lactobacillus bacteria. The process of fermentation as in Dr Ohhira's Probiotic OMX 12+ overcomes this limitation.
There are also other manufacturer's that produce probiotics that overcome this limitation--just need to read labels. And once in the gut, these probiotics do implant.