Probiotic drinks are marketed as helping to improve immunity. Some people who drink them experience side effects which can be life threatening--these people should avoid probiotic drinks. For other people, the side effects they feel can be mild. Probiotics contain beneficial bacteria that repopulates the intestines. These bacteria can do more harm to people with certain kinds of health conditions or those who take certain medications.
Bloating and Gas
Some people using probiotic drinks may experience bloating and/or gas, according to the National Center for Complementary and Alternative Medicine. This side effect is usually mild. NutraLegacy says that probiotics are intended to act as a therapy to get rid of bloating and gas, but the drinks could have a paradoxical effect in those who develop this side effect.
Additional or Intestinal Infections
For people with underlying health conditions or compromised immune systems, the bacteria in probiotic drinks can cause them to develop intestinal infections or other kinds of infections requiring antibiotic treatment, according to both NCAM and the NutraLegacy website.
Symptoms can include a skin rash, bloody stools and fever.
If the patient is taking an immunosuppressive medication, the probiotic drinks can interact with the medication and potentially cause a life-threatening condition. For this reason, people taking these medications should avoid probiotics, according to the NutraLegacy website.
Diarrhea and Abdominal Pain
Probiotic drinks can cause some people to develop abdominal pain and diarrhea, according to the NutraLegacy website. These people need to decide if these side effects are worth the benefits of drinking a probiotic.
Unhealthy Metabolic Activity
Probiotic drinks can trigger what is called "unhealthy metabolic activity." This side effect can include an overstimulated immune system or gene transfer, which means transfer of genetic material into a cell, according to the NutraLegacy website and NCAM.
Some people with compromised or impaired immune systems should consult with their doctors before beginning a diet heavy in probiotics. These drinks, if consumed by a patient with an impaired immune system, can cause severe fungal infection. For these patients, the probiotic drinks do more harm than good, according to the NutraLegacy website.