In America and many other parts of the world, the bacteria in yogurt is killed by pasteurization before it gets to the grocery store. Some manufacturers have begun adding probiotics back into the yogurt after pasteurization because of the health benefits it offers.
There is some evidence that yogurt with probiotics may help strength the immune system. Based on this evidence, several studies have been done on the effect that yogurt with probiotics has on the health of people with HIV/AIDS. The study results have been mixed. At this point it is possible that yogurt with probiotics helps strength the immune system of people with HIV/AIDS, but it is impossible to say for certain.
However the studies did find one side effect of yogurt with probiotics that many people with HIV/AIDS can benefit from.
People with HIV/AIDS who eat yogurt with probiotics everyday for several weeks have better digestion, less diarrhea, and better retention of nutrients. In fact, in most studies, people with moderate diarrhea who ate yogurt with probiotics everyday stopped having diarrhea entirely.
Diarrhea is a major complication of HIV/AIDS that can be life threatening without proper treatment. Severe diarrhea leads to dehydration, loss of important nutrients, and prevents the body from absorbing medication. So a way to prevent diarrhea in people who have HIV/AIDS is a big deal. Diarrhea can be caused by a wide variety of opportunistic infections, HIV damage to the gut, or ARVs.