Seriously, the problem is that each individual is different. Most people still manufacture some lactase, even if they are LI, so they only need sufficient additional lactase to balance out what they're missing. And the type of food eaten, how and when it is eaten, and even when the lactase is taken all have effects on what the symptoms might be. The most I can say is, maybe. Different bacteria like lactose to different extents.
Lactobacillus is a genus of bacteria.
They have the property of making their own lactase, the enzyme that digests lactose. So there is some logic in thinking that increasing the concentration of lactobacillus in one's colon would lessen LI symptoms. The big question is whether taking the pills would actually do that. And I just don't know if that's true. There has been much more attention paid to the role of colonic bacteria in LI over the past few years, but I don't know of any solid research that has anything to say about whether lactobacillus or acidophilus actually helps, whether it's acting as a placebo, or whether other factors are involved.