Most medications and supplements including probiotics have both desired clinical outcomes and undesired side effects, which play a role when considering them as a modality for treatment. This review is an update about the advantages and disadvantages associated with the use of probiotics as part of a therapeutic armamentarium in health and in disease. Advantages of probiotics run across multiple organ systems and a wide age spectrum. They promote cardiovascular health, accelerate recovery from diarrhea, decrease risk of necrotizing enterocolitis, limit inflammation in IBD, and promote wound healing. Additionally, probiotics serve in combating chronic diseases for patients with type 2 diabetes and HIV/AIDS. Moreover, probiotics play a significant role in the treatment and/or prevention of cancers, especially those of the colon and bladder. On the other hand, probiotics pose serious threats to immunocompromised, genetically predisposed individuals, children and infants. Using probiotics can lead to bacteremia, fungemia or septicemia. Also, probiotics can cause pneumonia, abdominal abscesses, increase platelet aggregation and trigger antibiotic resistance among others. In conclusion, in vitro and in vivo data from our laboratory and others support the selective evidence based use of probiotics. Actually, a huge number of organisms inhabit the human gut and consequently cause a complex network of the interactions of those organisms with each other and with the host cells, which stresses on the necessity of extra care in the use of probiotics as therapy
