COVID-19 is a viral disease caused by the SARS-CoV-2 virus. The name COVID-19 was announced by the World Health Organization (WHO) and means literally “CO” – corona, “VI” – virus, “D” – disease and the number 19 indicates the year of the appearance of the virus – 2019 (Corona-Virus-Disease-2019). The difference between the coronavirus and COVID-19 is that COVID-19 is the disease and the coronavirus is the causative agent of the disease. The purpose of this article is to present the available literature on: What do probiotics have in common with the SARS-CoV-2 virus?


  • mainly affects the lungs and respiratory tract,
  • it can also lead to symptoms and signs related to the digestive tract,
  • the typical clinical symptoms of COVID-19 include: pneumonia, dry cough, fever, fatigue, myalgia and dyspnea, headache, sore throat, rhinorrhoea and gastrointestinal symptoms. Most of these symptoms are related to the lungs,
  • characteristically involves a hyperimmune response, also known as a “cytokine storm”.

Facts about the role of probiotics in the prevention and treatment of COVID-19:

1. Doctors at  Zhejiang University School of Medicine in The COVID-19 Prevention and Treatment Handbook describe (March 2020):

„Some COVID-19 patients have gastrointestinal symptoms (such as abdominal pain and diarrhea) due to direct viral infection of the intestinal mucosa or antiviral and anti-infective drugs. There has been report that the intestinal microecological balance is broken in COVID-19 patients, manifesting a significant reduction of the intestinal probiotics such as lactobacillus and bifidobacterium. Intestinal microecological imbalance may lead to bacterial translocation and secondary infection, so it is important to maintain the balance of intestinal microecology by microecological modulator and nutritional support”.

More information about this publication are in another article on our blog:


2. Italian scientists Luana Conte and Domenico Maurizio Toraldo write (June 2020):

„preventing SARS-CoV-2 infection by maintaining high hygiene by washing our hands, avoiding contact with infected people and reinforcing the immune system are the best strategies. Although there is no clinical evidence that targeting the gut–lung microbiota axis would play a therapeutic role in COVID-19 infection, we believe that the manipulation of microbial patterns through the use of probiotics, prebiotics and a high-fibre diet may help to reduce cell inflammation, maintain a healthy gut microbial diversity and strengthen the immune system”.


3. Scientists Firoz Anwar, Hisham N. Altayb, Fahad A. Al-Abbasi, Abdulrahman L. Al-Malki, Mohammad Amjad Kamal and Vikas Kumar explain (June 2020):

The authors in their publication entitled Antiviral effects of probiotic metabolites on COVID-19 explain the importance of metabolites of probiotic bacteria – bacteriocin (plantaricin) in blocking the SARS-CoV-2 virus. „Assessment of our results on COVID-19 through computational studies (…) can be used as one of the anti-COVID-19 mechanistic approaches through probiotic intake. The present computational representation and molecular dynamics study clearly demonstrates the antiviral activity (Aanouz et al., 2020) of Plantiricin compounds, through multiple mechanistic approach by metabolic product of Lactobacillus plantarum. The blocking of main structural protein S is one of the essential accessory protien, playing a vital role in the life cycle of SARS-CoV-2”.


4. Scientists Aravind Sundararaman, Mousumi Ray, P.V. Ravindra and Prakash M. Halami describe (August 2020):

„Protection from viral infection has shown as a benefit of probiotic action. The probiotics exert their beneficial effects through modulation of host immune responses, maintain gut homeostasis and produce interferon thereby suppressing the virus induced cytokine storm. (…) Immune stimulation through probiotics potentially promote prolonged resistance to virus infections and diseases in humans”.

More information about this publication are in another article on our blog:


5. Scientists from India Debojyoti Dhar, Abhishek Mohanty describe (August 2020):

„Role of the gut microbiota in influencing lung diseases has been well articulated. It is also known that respiratory virus infection causes perturbations in the gut microbiota. Presence of SARS Cov2 RNA in the stool of some patients and diarrhoea in few suggest a subtle link between the lung and the intestine. Although, no faecal-oral transmission is reported, yet it can be assumed that many asymptomatic children and adults may shed infectious virus particles in the stool leading to infection in others. Gut microbiota diversity and the presence of beneficial microorganisms in the gut may play an important role in determining the course of this disease. So, it is quite a possibility that gut dysbiosis may be influencing the clinical manifestation in Covid-19 as well. (…) Another line of action may be to prophylactically provide specialized supplements including prebiotics, probiotics to care givers who are in the front line in tackling this disease”.


6. Scientists from Pasteur Institute of Iran Mehran Mahooti, Seyed Mohammad Miri, Elahe Abdolalipour, Amir Ghaemi explain (August 2020):

„Respiratory virus infections are among the most prevalent diseases in humans and contribute to morbidity and mortality in all age groups. To ensure protection against emerging respiratory tract infections, the development of new strategies based on modulating the immune responses is essential. The use of probiotic components has substantially increased due to their effects on immune responses (…). It has been shown that probiotics can regulate immunomodulatory responses of intestinal epithelial cells. There is a key point that may correlate respiratory virus diseases to each other, the emergence of imbalanced immune responses as a result of virus-host interactions. Employment of probiotics for modulating the inflammatory immune responses upon virus infection has shown promising results. The newly emerged SARS-CoV-2, the agent of COVID-19, has shown to induce inflammatory responses, which is in direct correlation with the severity of symptoms and inpatient time. Based on this observation, and although there are not any available data substantiating the effectiveness of probiotics on SARS-CoV-2 infection, previously proven antiviral properties of probiotics against different respiratory viruses may suggest probiotics as a safe and available complementary medicine against COVID-19 disease”.


7. Scientists Hüseyin S Bozkurt and Eamonn MM Quigley describe (October 2020):

„some strains of Bifidobacteria, for example, possess especially potent immune modulating effects. These bacteria have the potential to ameliorate the ‘cytokine storm’ through a differential effect on pro- and anti-inflammatory cytokines. Given the close relationship that seems to exist between viral replication and gastrointestinal immunity, a probiotic strategy that targets and modulates the immune response might be effective in reducing viral replication. The known anti-inflammatory activity of certain bifidobacteria suggest that these bacteria could play an important role in abrogating the inflammatory response that seems so characteristic of this virus”.


8. Scientists from Cambridge University Gemma E. Walton, Glenn R. Gibson and Kirsty A. Hunter explain (October 2020):

„SARS-CoV-2 most commonly manifests as a URTI (upper respiratory tract infections) but can, in more severe cases, proliferate deeper into the lungs to become a lower respiratory tract infection (LRTI). Whilst evidence is still being collated, recent meta-analyses of randomised control trials have indicated that probiotics can reduce the incidence and severity of ventilator-associated pneumonia. In a study by Mahmoodpoor et al. (53), for example, probiotic supplementation shortened the duration of ventilator use in critically ill patients. As mentioned, there is a body of evidence supporting a prophylactic role of probiotics, prebiotics and synbiotics in reducing symptoms with regard to URTI. Beneficial effects include enhancement of the intestinal epithelial barrier, competition with pathogens for nutrients and adhesion to the intestinal epithelium, production of antimicrobial substances and modulation of the host immune system (both innate and adaptive)”.


9. Scientists Amin N. Olaimat, Iman Aolymat, Murad Al-Holy, Mutamed Ayyash, Mahmoud Abu Ghoush, Anas A. Al-Nabulsi, Tareq Osaili, Vasso Apostolopoulos, Shao-Quan Liu and Nagendra P. Shah describe (October 2020):

„Some anti-viral, anti-inflammatory and anti-malarial drugs have been applied to treat COVID-19; however, none of these medications have been approved as effective curative treatments against COVID-19. Therefore, other safe strategies such as probiotics and prebiotics could be applied to prevent or treat COVID-19. Probiotic bacteria have been shown to have a number of beneficial immune and health effects. They not only enhance the bioavailability of nutrients and moderate health, they are also involved in regulating the bacterial ecosystem and module immune cells”.


10. Gastroenterologist dr Tadeusz Tacikowski explain (December 2020):

„As extensive research has shown, a large number of people with severe COVID-19 had an impaired microbiome. This likely affected the functioning of the entire immune system and could cause an abnormal response to the virus. Improving the gut microbiome can be achieved through the use of probiotics, or “good” bacteria. The most important of them are Lactobacillus and Bifidobacterium. There are currently no strict recommendations regarding the use of probiotics in COVID-19 patients. However, it can be safely assumed that good intestinal microbiota will have a positive effect on the patient’s condition, and the use of probiotics will not cause any side effects ” – emphasizes dr Tacikowski.

(reference (in polish):

A year ago, we did not know anything about the SARS-CoV-2 virus. Today we know more and more. During this year, many research projects on COVID-19 have started. Work is underway not only on the development of a vaccine, but also on the impact of probiotics on the SARS-CoV-2 virus. Research is ongoing, but scientists agree: PROBIOTICS have a number of beneficial immune and health effects. Ensuring the intestinal microbiological balance is essential for the proper functioning of the human body.