Conv. Plasma
Nigella Sativa
Vitamin A
Vitamin C
Vitamin D

Home   COVID-19 treatment studies for Probiotics  COVID-19 treatment studies for Probiotics  C19 studies: Probiotics  Probiotics   Select treatmentSelect treatmentTreatmentsTreatments
Aspirin Metformin
Bamlanivimab Molnupiravir
Bromhexine Nigella Sativa
Budesonide Nitazoxanide
Casirivimab/i.. Povidone-Iod..
Colchicine Probiotics
Conv. Plasma Proxalutamide
Curcumin Quercetin
Favipiravir Remdesivir
Fluvoxamine Sotrovimab
Hydroxychloro.. Vitamin A
Iota-carragee.. Vitamin C
Ivermectin Vitamin D
Melatonin Zinc

Other Adoptionérre.. (DB RCT)35%0.65 [0.53-0.80]no recov.69/147105/146Improvement, RR [CI]TreatmentControlVeterini29%0.71 [0.41-1.22]viral time15 (n)15 (n)Tau​2 = 0.00; I​2 = 0.0%Early treatment34%0.66 [0.55-0.80]69/162105/16134% improvementd'Ettorre87%0.13 [0.01-2.33]death0/284/42Improvement, RR [CI]TreatmentControlCeccarelli64%0.36 [0.18-0.68]death10/8834/112Shah (RCT)11%0.89 [0.75-1.06]recov. time30 (n)30 (n)CT​1Li-12%1.12 [0.74-1.69]no disch.30/12341/188Zhang14%0.86 [0.77-0.96]hosp. time150 (n)150 (n)Ceccarelli70%0.30 [0.01-7.02]death0/401/29Ivashkin (RCT)-2%1.02 [0.26-3.97]death4/994/101Tau​2 = 0.02; I​2 = 44.9%Late treatment16%0.84 [0.69-1.02]44/55884/65216% improvementLouca8%0.92 [0.85-0.99]casesImprovement, RR [CI]TreatmentControlDi Pierro (RCT)98%0.02 [0.00-0.33]cases0/6424/64Ahanchian (DB RCT)73%0.27 [0.03-2.25]symp. case1/294/31Tau​2 = 2.41; I​2 = 76.4%PrEP75%0.25 [0.03-1.91]1/9328/9575% improvementAll studies20%0.80 [0.69-0.93]114/813217/90820% improvement12 probiotics COVID-19 Oct 24, 20211 CT: study uses combined treatmentTau​2 = 0.02; I​2 = 62.2%; Z = 2.97Effect extraction pre-specifiedFavors probioticsFavors control
Database of all probiotics COVID-19 studies. The immune effects of probiotics are strain-specific and studies use different strains. Submit updates/corrections.
Restrict:    All    Early    Late    PrEP    PEP
Oct 13
Late Ivashkin et al., Probiotics Antimicrob Proteins, doi:10.1007/s12602-021-09858-5 (Peer Reviewed) death, ↑2.0%, p=1.00 Efficacy of a Probiotic Consisting of Lacticaseibacillus rhamnosus PDV 1705, Bifidobacterium bifidum PDV 0903, Bifidobacterium longum subsp. infantis PDV 1911, and Bifidobacterium longum subsp. longum PDV 2301 in the Treatment of Hospitalized Patients with COVID-19: a Randomized Controlled Trial
Details   RCT 200 patients, 99 treated with a probiotic (Lacticaseibacillus rhamnosus PDV 1705, Bifidobacterium bifidum PDV 0903, Bifidobacterium longum subsp. infantis PDV 1911, and Bifidobacterium longum subsp. longum PDV 2301). There was no sign..
Aug 30
Late Rathi et al., Medicines, doi:10.3390/medicines8090047 (Peer Reviewed) A Randomized Controlled Trial of the Efficacy of Systemic Enzymes and Probiotics in the Resolution of Post-COVID Fatigue
Details   RCT 200 long-COVID patients in India, 100 treated with ImmunoSEB and ProbioSEB CSC3, showing improved recovery of post-COVID-19 fatigue with treatment. CTRI/2021/05/033576.
Aug 23
Late Ceccarelli et al., Nutrients, doi:10.3390/nu13082898 (Peer Reviewed) death, ↓70.4%, p=0.42 Oxygen Sparing Effect of Bacteriotherapy in COVID-19
Details   Prospective analysis of 69 severe COVID-19 patients requiring non-invasive oxygen therapy, 40 treated with probiotic formulation SLAB51, showing lower oxygen requirements and higher blood levels of pO2, O2Hb and SaO2 with treatment. Autho..
Aug 4
Late Zhang et al., Therapeutic Advances in Gastroenterology, doi:10.1177/17562848211035670 (Peer Reviewed) hosp. time, ↓13.6%, p=0.009 Probiotics use is associated with improved clinical outcomes among hospitalized patients with COVID-19
Details   Retrospective 375 patients in China, 179 treated with probiotics (Bifidobacterium, Lactobacillus, and Enterococcus), showing improved clinical outcomes with treatment.
Jun 30
Early Veterini et al., Indian Journal of Forensic Medicine & Toxicology, 15:2 (Peer Reviewed) viral- time, ↓29.0%, p=0.22 Probiotics Intake as Adjunct Therapy for Infected Health-Care with SARS COV-2
Details   Small case control analysis with 15 probiotics patients and 15 contol patients, showing no significant differences. PCR tests were only done weekly. Dosage is unknown. 115/LOE/301.4.2/IX/2020.
Jun 24
PrEP Wang et al., Front. Bioeng. Biotechnol., doi:10.3389/fbioe.2021.646184 (Peer Reviewed) Oropharyngeal Probiotic ENT-K12 Prevents Respiratory Tract Infections Among Frontline Medical Staff Fighting Against COVID-19: A Pilot Study
Details   Prophylaxis RCT in China with 98 healthcare workes in close contact with COVID-19 patients treated with Bactoblis oropharyngeal probiotic containing S. thermophilus ENT-K12, and 95 control patients, showing lower incidence of respiratory ..
Jun 1
Late Meskina et al., Therapeutic Archive, doi:10.26442/00403660.2021.04.200835 (Peer Reviewed) Efficiency of application of sorbed probiotics in complex therapy of pneumonia caused by SARS-CoV-2
Details   RCT 100 pneumonia patients in Russia, showing faster symptom resolution with probiotic treatment (B. bifidum 1).
May 31
PrEP Ahanchian et al., Open Journal of Nursing, doi:10.4236/ojn.2021.115025 (Peer Reviewed) symp. case, ↓73.3%, p=0.35 Synbiotic for Prevention of SARS-Cov2 Infection in High Risk Hospital Staffs: A Randomized Controlled Trial
Details   Small RCT 60 healthcare workers in Iran, showing lower cases with treatment but without statistical significance. Once daily oral synbiotic capsule (Lactocare®) containing 1 billion CFU L. (Lactobacillus) casei, L. rhamnosus, Streptococcu..
May 24
Early Gutiérrez-Castrellón et al., medRxiv, doi:10.1101/2021.05.20.21256954 (Preprint) no recov., ↓34.7%, p<0.0001 Efficacy and safety of novel probiotic formulation in adult Covid19 outpatients: a randomized, placebo-controlled clinical trial
Details   RCT 293 outpatients in Mexico, 147 treated with a probiotic composed of three L. plantarum strains (KABP022, KABP023 and KABP033) and one P. acidilacti strain (KABP021), showing improved recovery with treatment. There were no hospitalizat..
Apr 7
Review Di Pierro, F., Minerva Medica, doi:10.23736/S0026-4806.20.06570-2 (Review) (Peer Reviewed) review A possible probiotic (S. salivarius K12) approach to improve oral and lung microbiotas and raise defenses against SARS-CoV-2
Details   Review of the potential use of S. salivarius K12 for COVID-19. Author notes that strain K12 of Streptococcus salivarius may reduce occurrence of viral upper respiratory tract infections, possibly due to its ability to stimulate IFN-γ rele..
Mar 19
Review Kurian et al., Archives of Medical Research, doi:10.1016/j.arcmed.2021.03.002 (Review) (Peer Reviewed) review Probiotics in Prevention and Treatment of COVID-19: Current Perspective and Future Prospects
Details   Review of probiotics role in regulating the immune system and use in viral infections, and studies on the association of microbiota with COVID-19 patients. Authors suggest that probiotics supplementation could reduce COVID-19 morbidity an..
Mar 12
PrEP Di Pierro et al., Minerva Medica, doi:10.23736/S0026-4806.21.07487-5 (Peer Reviewed) cases, ↓98.0%, p<0.0001 The administration of S. salivarius K12 to children may reduce the rate of SARS-CoV-2 infection
Details   Interim report on an RCT for prophylactic treatment with S. salivarius K12, showing significantly lower cases with treatment. Only patients with symptoms or known positive contacts were tested. Trial identification/registration details ar..
Mar 5
Late Li et al., International Immunopharmacology, doi:10.1016/j.intimp.2021.107531 (Peer Reviewed) no disch., ↑11.8%, p=0.68 The role of probiotics in coronavirus disease-19 infection in Wuhan: A retrospective study of 311 severe patients
Details   Retrospective 311 severe condition hospitalized patients in China, 123 treated with probiotics, showing slower viral clearance and recovery with treatment. Authors note that probiotics were able to moderate immunity and decrease the incid..
Feb 13
Review Singh et al., Nutrition Research, doi:10.1016/j.nutres.2020.12.014 (Review) (Peer Reviewed) review Probiotics: A potential immunomodulator in COVID-19 infection management
Details   Review of studies supporting the use of probiotics for respiratory infections and identification of microbial strains potentially beneficial for COVID-19.
Feb 2
Late Shah et al., Advances in Clinical Toxicology, doi:10.23880/act-16000204 (Peer Reviewed) recov. time, ↓10.8%, p=0.19 Potential of the Combination of a Systemic Enzyme Complex and Probiotics administration to Combat COVID-19: A Randomized Open Label Prospective Analysis
Details   Small RCT 60 patients in India, 30 treated with ImmunoSEB and ProbioSEB CSC3, showing faster recovery with treatment. CTRI/2020/09/027685, CTRI/2020/08/027168.
Jan 11
Late Ceccarelli et al., Frontiers in Medicine, doi:10.3389/fnut.2020.613928 (Peer Reviewed) death, ↓64.2%, p=0.003 Oral Bacteriotherapy in Patients With COVID-19: A Retrospective Cohort Study
Details   Retrospective 200 severe condition hospitalized patients in Italy, 88 treated with probiotic Sivomixx, showing lower mortality with treatment.
Dec 15
Review Stavropoulou et al., Frontiers in Nutrition, doi:10.3389/fnut.2020.614986 (Review) (Peer Reviewed) review Probiotics as a Weapon in the Fight Against COVID-19
Details   Review of the potential benefits of probiotics for COVID-19.
Nov 30
PrEP Louca et al., BMJ Nutrition, Prevention & Health, doi:10.1136/bmjnph-2021-000250 (preprint 11/30/20) (Peer Reviewed) cases, ↓8.5%, p=0.03 Modest effects of dietary supplements during the COVID-19 pandemic: insights from 445 850 users of the COVID-19 Symptom Study app
Details   Survey analysis of dietary supplements showing probiotic usage associated with lower incidence of COVID-19. These results are for PCR+ cases only, they do not reflect potential benefits for reducing the severity of cases. A number of bias..
Oct 5
Review Olaimat et al., npj Science of Food, doi:10.1038/s41538-020-00078-9 (Review) (Peer Reviewed) review The potential application of probiotics and prebiotics for the prevention and treatment of COVID-19
Details   Review of the immune benefits of probiotics and clinical studies for the preventation and treatment of respiratory infections, recommending trials of probiotics for COVID-19.
Jul 7
Late d'Ettorre et al., Frontiers in Medicine, doi:10.3389/fmed.2020.00389 (Peer Reviewed) death, ↓87.0%, p=0.14 Challenges in the Management of SARS-CoV2 Infection: The Role of Oral Bacteriotherapy as Complementary Therapeutic Strategy to Avoid the Progression of COVID-19
Details   Retrospective 70 hospitalized patients in Italy, 28 treated with probiotic Sivomixx, showing lower risk of respiratory failure and faster recovery with treatment.
May 8
Review Baud et al., Frontiers in Public Health, doi:10.3389/fpubh.2020.00186 (Review) (Peer Reviewed) review Using Probiotics to Flatten the Curve of Coronavirus Disease COVID-2019 Pandemic
Details   Review of data supporting the use of probiotics for COVID-19 and mechanisms of action.
Meta Hao et al., Cochrane Database of Systematic Reviews, doi:10.1002/14651858.CD006895.pub3 (Preprint) (meta analysis) meta-analysis Probiotics for preventing acute upper respiratory tract infections
Details   Meta analysis of 12 RCTs with 3,720 patients showing probiotics reduced acute upper respiratory tract infections.
Please send us corrections, updates, or comments. Vaccines and treatments are both extremely valuable and complementary. All practical, effective, and safe means should be used. Elimination of COVID-19 is a race against viral evolution. No treatment, vaccine, or intervention is 100% available and effective for all current and future variants. Denying the efficacy of any method increases the risk of COVID-19 becoming endemic; and increases mortality, morbidity, and collateral damage. We do not provide medical advice. Before taking any medication, consult a qualified physician who can provide personalized advice and details of risks and benefits based on your medical history and situation. Treatment protocols for physicians are available from the FLCCC.
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Thanks for your feedback! Please search before submitting papers and note that studies are listed under the date they were first available, which may be the date of an earlier preprint.