• The probiotic bacteria can decrease viral infections
  • Mohammad Shayestehpour,1,* Forough Tavakoli,2 Shaghayegh Yazdani,3
    1. Autoimmune Diseases Research Center, Kashan University of Medical Sciences, Kashan, I.R. Iran
    2. Virology Department, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
    3. Department of Microbiology, Faculty of Advanced Science & Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran


  • Introduction: Viral infections of the upper respiratory and gastrointestinal tracts have periodically widespread outbreaks and can cause serious threats to public health. The rhinovirus, respiratory syncytial virus (RSV) and influenza viruses are the most common viral agents in upper respiratory tract infections, while rotavirus and norovirus frequently cause the gastrointestinal diseases. Vaccination has been exploited for the prevention of some viral infections such as influenza viruses. Producing vaccines against viruses is not easy, and there is not an effective vaccine for the majority of viruses. In addition, the antiviral drugs may be not effective enough because of the large number of viral species and their subtypes as well as the high mutation rate of viruses. Probiotics are defined as live microorganisms that confer a health benefit on the host. Recently, many studies have shown that several probiotic bacteria inhibit virus replication, and decrease viral infections. In the present study, we reviewed the effectiveness of several probiotics for the prevention of virally-induced infectious diseases.
  • Methods: We reviewed the literature regarding several probiotic agents with focus on the manuscripts which described a single probiotic to avoid the crosstalk between probiotics.
  • Results: Probiotics affect the innate and acquired immune systems. They can decrease the severity of viral infections in the gastrointestinal and upper respiratory tracts. The yoghurt fermented with Lactobacillus delbrueckii increased NK cell activity and reduced the risk of catching the common cold in older individuals. Lactobacillus paracasei shortened the duration of upper respiratory symptoms in viral infections. Lactobacillus rhamnosus decreased the occurrence and severity of cold symptoms and number of subjects with rhinovirus infection. This probiotic significantly decreased the repeated episodes of rotavirus diarrhea. Oral administration of Saccharomyces boulardii or Bifidobacterium lactis B94 decreased diarrheal duration in children with acute rotavirus gastroenteritis. Bifidobacterium animalis Bb12 significantly increased anti-rotavirus and anti-poliovirus IgA. Lactococcus lactis subsp. Lactis JCM 5805 significantly attenuated common cold symptoms through activation of human plasmacytoid dendritic and producing the large amounts of interferons. It decreased the incidence rate of influenza. Lactobacillus casei (DN-114 001) significantly redeuced the incidence and frequency of the viral diarrhea.
  • Conclusion: Efficacy of probiotics for the prevention and treatment of viral diseases has increased in recent years. Further studies are necessary in the future. Probiotics are expected to be applicable options for the prevention or treatment of viral infections.
  • Keywords: Bacteria, Probiotics, Infection, Virus