Probiotics as a Treatment for Infectious Diseases

Safety of Probiotics

Microorganisms that are "generally regarded as safe" include species of Lactobacillus and Bifidobacterium and certain yeast strains. Other bacteria, such as Enterococcus and Streptococcus strains, are not generally regarded as safe, but have been used as probiotics. Rarely has a lactic acid– producing bacterium posed a risk to an individual. However, theoretical adverse risks have been raised, including the potential for transmigration, colonization, or transfer of antibiotic resistance. These risks, which are speculative, could occur more often in immunocompromised patients, young children, and elderly patients. As such, caution should be exercised in recommending probiotics to these populations. Studies investigating probiotics have been relatively short in duration, limiting the long-term safety data and potential for serious adverse events. To make firm conclusions, more clinical trials investigating the safety of probiotics must be conducted.