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Probiotics for COVID-19
29 studies with >19,000 patients
Serious outcome risk
Probiotics
Control
Significantly lower risk for mortality, hospitalization, progression, recovery, and cases.
Probiotic efficacy depends on the specific strains used.
COVID-19 Probiotics studies · October 2026
Probiotic efficacy depends on the specific strains used. Specific microbes may decrease or increase COVID-19 risk1. Probiotics were adopted in 1 country. Recent:
Morikawa
Bačić
Soleimani
Andrade-Platas.
Covid Analysis Probiotics reduce COVID-19 risk: real-time meta-analysis of 29 studies (Version 31)
Significantly lower risk is seen for mortality, hospitalization, progression, recovery, and cases. 13 studies from 12 independent teams in 9 countries show significant benefit. Meta-analysis using the most serious outcome reported shows..
May 17
 Morikawa et al., Virulence, doi:10.1080/21505594.2026.2673650 Multicenter retrospective observational study on the clinical effectiveness of butyrate-producing Clostridium butyricum containing probiotics in patients with COVID-19
Retrospective 283 hospitalized COVID-19 patients in Japan showing potential benefit with butyrate-producing Clostridium butyricum (CB)-containing probiotic preparations, however this study has a number of significant issues: Unreproducibl..
May 7
 Soleimani et al., Enzyme and Microbial Technology, doi:10.1016/j.enzmictec.2026.110899 Antiviral activity of postbiotics from Bifidobacterium animalis subsp. lactis BB-12 and Lacticaseibacillus rhamnosus GG against SARS-CoV-2: In-vitro and food model evaluation
In vitro study showing benefit with postbiotics derived from Lacticaseibacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB-12 against SARS-CoV-2. Authors report that these non-viable microbial metabolites, including supern..
Mar 25
 Bačić et al., Microorganisms, doi:10.3390/microorganisms14040734 Multi-Strain Probiotic Intervention Modestly Modulates Microbial Composition and Inflammatory Profile in Individuals with Long COVID
Analysis of 74 participants (34 receiving a 12-week multi-strain probiotic containing Saccharomyces boulardii, Lacticaseibacillus rhamnosus GG, and two Lactiplantibacillus plantarum strains, and 40 non-supplemented controls) showing modes..
Nov 26
2025
 Andrade-Platas et al., European Journal of Pediatrics, doi:10.1007/s00431-025-06587-7 A probiotic containing L. plantarum and P. acidilactici strains for treating upper respiratory infection in children aged 6 months to 5 years: a randomized, double-blind trial
RCT 75 pediatric outpatients (6 months to 5 years) with specialist-diagnosed upper respiratory infections with pharyngitis, showing reduced duration of fever and pain/discomfort with a probiotic formula containing L. plantarum KABP022, KA..
Oct 25
2025
 Yamamoto et al., Infectious Diseases and Therapy, doi:10.1007/s40121-025-01246-8 Efficacy of Lactococcus lactis Strain Plasma in Patients with Mild COVID-19: A Multicenter, Double-Blinded, Randomized-Controlled Trial (PLATEAU Study)
26% improved recovery (p<0.0001) and 62% improved viral clearance (p=0.21). RCT 100 outpatients with mild COVID-19 showing no significant difference in overall symptom severity with Lactococcus lactis strain Plasma (LC-Plasma). However, post hoc analysis revealed a significantly higher proportion of patients with..
Sep 26
2025
 Chau et al., Nutrition and Health, doi:10.1177/02601060251378200 Effectiveness of probiotics on COVID-19 prevention and treatment against mild COVID-19 in outpatient care: A systematic review
Systematic review of 8 randomized controlled trials and 1 pre-post study examining probiotics for COVID-19 prevention and treatment in outpatients with mild symptoms, showing lower COVID-19 cases and improved recovery with treatment.
Sep 11
2025
 Portero et al., Probiotics and Antimicrobial Proteins, doi:10.1007/s12602-025-10758-1 Construction of Synthetic Probiotic Bacteria for In Situ Delivery of Anti-SARS-CoV-2 Nanobodies
In vitro study showing that genetically modified Lactococcus lactis bacteria expressing anti-SARS-CoV-2 nanobodies can inhibit viral infection by blocking spike protein-ACE2 receptor interaction.
Jul 31
2025
 Takada et al., Frontiers in Cellular and Infection Microbiology, doi:10.3389/fcimb.2025.1556344 Heat-killed Lactobacillus acidophilus suppresses SARS-CoV-2 infection in the human intestinal epithelial cell line Caco-2
In vitro study showing that heat-killed Lactobacillus acidophilus (HK-LA) reduces SARS-CoV-2 infection by approximately 30% in Caco-2 human intestinal epithelial cells. Authors found that HK-LA treatment significantly reduced viral genome..
Jul 27
2025
 Bajić et al., Innate Immunity, doi:10.1177/17534259251362023 Immunity's core reset: Synbiotics and gut microbiota in the COVID-19 era
Review of synbiotics and gut microbiota modulation in COVID-19 and long COVID. Authors examine how gut microbiome dysbiosis during COVID-19 infection contributes to immune dysfunction, excessive inflammation, and cytokine storm, while syn..
May 26
2025
 Bigman et al., Nutrients, doi:10.3390/nu17111802 A Comprehensive Scoping Review on Diet and Nutrition in Relation to Long COVID-19 Symptoms and Recovery
Scoping review of 50 studies (27 interventional, 23 observational) examining the role of diet and nutrition in long COVID-19 symptom management and recovery. Approximately 76% of included studies reported significant improvements in sympt..
May 20
2025
 Sanz et al., PLOS One, doi:10.1371/journal.pone.0323910 Hospitalised children with COVID-19 display an aberrant intestinal microbiota and a shift in faecal compounds related with the metabolism of vitamins and lipids
Analysis of 16 children hospitalized with COVID-19 and 20 age-matched healthy controls showing altered gut microbiota and faecal metabolomic profiles in infected children. COVID-19 patients had higher abundance of opportunistic bacteria a..
May 5
2025
 Zhu et al., Elsevier BV, doi:10.2139/ssrn.5239044 Comparative Effectiveness of Oral Nutritional Supplements in Preventing Respiratory Tract Infections Among Adults: A Systematic Review and Network Meta-Analysis
Network meta-analysis of 127 RCTs evaluating the effectiveness of oral nutritional supplements in preventing respiratory tract infections (RTIs), finding that flavonoids, probiotics, multiple micronutrient supplements, and moderate-dose v..
Apr 9
2025
 Martino et al., mBio, doi:10.1128/mbio.04015-24 SARS-CoV-2 infectivity can be modulated through bacterial grooming of the glycocalyx
In vitro study showing that certain gut bacteria can modulate SARS-CoV-2 infection by degrading heparan sulfate (HS) on cell surfaces. Authors found that the abundance of HS-modifying bacteria inversely correlates with age, sex, and COVID..
Nov 18
2024
 Taufer et al., Microorganisms, doi:10.3390/microorganisms12112353 In Silico Analysis of Probiotic Bacteria Changes Across COVID-19 Severity Stages
Reanalysis of publicly available microbiome datasets from 7 studies totaling 581 COVID-19 patients and controls, showing significant differential abundance of beneficial bacterial genera, particularly Bifidobacterium and Bacteroides, acro..
Nov 11
2024
 Fazli et al., Journal of Medical Bacteriology, 12:4 Possible Link between Gut Microbiota, Diet, and COVID-19 Infection
Review of the relationship between gut microbiota, diet, and COVID-19 infection. Authors analyze how SARS-CoV-2 infection affects gut microbiota composition and how dietary factors may influence disease outcomes. Studies show COVID-19 pat..
Nov 8
2024
 Horvath et al., Nutrients, doi:10.3390/nu16223840 Alteration of the Gut–Lung Axis After Severe COVID-19 Infection and Modulation Through Probiotics: A Randomized, Controlled Pilot Study
Randomized controlled trial of 21 patients after severe COVID-19 infection showing improved microbial richness, stool metabolites, innate immune function, and quality of life with a multispecies probiotic compared to placebo over 6 months..
Oct 6
2024
 Santa et al., Frontiers in Nutrition, doi:10.3389/fnut.2024.1465324 Comparative analysis of COVID-19 responses in Japan and Africa: diet, phytochemicals, vitamin D, and gut microbiota in reducing mortality—A systematic review and meta-analysis
Comparative analysis of COVID-19 responses in Japan and Africa, focusing on diet, phytochemicals, vitamin D, and gut microbiota in reducing mortality. Authors conducted a systematic review and meta-analysis to investigate the unexpectedly..
Sep 18
2024
 Kaushal, A., Journal of Translational Medicine, doi:10.1186/s12967-024-05587-9 Nutraceuticals and pharmacological to balance the transitional microbiome to extend immunity during COVID-19 and other viral infections
Review of nutraceuticals and pharmacological interventions to balance the microbiome and boost immunity during COVID-19 and other viral infections. Authors propose that optimal usage of probiotics, dietary fibers, vitamins, minerals, omeg..
Sep 16
2024
 Mu et al., Journal of Agriculture and Food Research, doi:10.1016/j.jafr.2024.101422 Anti-inflammatory and Nutritional Interventions Against SARS-CoV-2: A Comprehensive Review
Review of anti-inflammatory and nutritional interventions against SARS-CoV-2. Authors emphasize the importance of a healthy immune response in reducing the severity of COVID-19, especially in high-risk groups like the elderly and those wi..
Aug 8
2024
 Vaishnani et al., medRxiv, doi:10.1101/2024.08.07.24311606 Hydrogen Sulfide (H₂S)-Producing Oral Bacteria May Protect Against COVID-19
Bioinformatics analysis of oral microbiome data from 244 healthy subjects across 8 countries showing an association between higher levels of hydrogen sulfide-producing oral bacteria and lower COVID-19 mortality rates. Authors hypothesize ..
Aug 5
2024
 Li et al., BMC Microbiology, doi:10.1186/s12866-024-03423-0 Large-scale genetic correlation studies explore the causal relationship and potential mechanism between gut microbiota and COVID-19-associated risks
Mendelian randomization study based on large-scale GWAS data from 18,340 individuals showing a causal relationship between 14 gut microbiota taxa and reduced or increased risk of COVID-19 severity, hospitalization, or susceptibility. The ..
Jul 16
2024
 Giancola et al., Microorganisms, doi:10.3390/microorganisms12071443 Efficacy of a Multistrain Synbiotic Treatment in Acute and Post-Acute COVID-19 Patients: A Double-Blind, Placebo-Controlled Randomized Trial
33% improved recovery (p=0.32). RCT 52 acute COVID-19 inpatients in Italy showing a multistrain synbiotic formula prevented a decrease in gut microbiota diversity and prevented decreases in lymphocyte count and hemoglobin levels compared to placebo. The probiotic group ..
May 10
2024
 Hazan et al., Cureus, doi:10.7759/cureus.60038 Bifidobacterium Against COVID-19: A Mother and Her Newborn’s Gut Microbiome
Case report of a mother and her newborn infected with COVID-19 within two weeks of the baby's birth. Authors propose that the disease course was altered by maternal supplementation of vitamins C and D and zinc starting after exposure on d..
Jan 29
2024
 Taufer et al., Microorganisms, doi:10.3390/microorganisms12020284 Lactobacilli in COVID-19: A Systematic Review Based on Next-Generation Sequencing Studies
Review of nine studies using next generation sequencing to analyze the association between lactobacilli and COVID-19, focusing on the gut and upper respiratory tract microbiota. Studies showed that lactobacilli have reduced abundance in C..
Jan 10
2024
 Shimizu et al., Acute Medicine & Surgery, doi:10.1002/ams2.923 Dysbiosis of gut microbiota in patients with severe COVID‐19
Retrospective 30 mechanically ventilated COVID-19 patients without prior antibiotic use showing dysbiosis of gut microbiota with decreases in commensals like Bacteroides, Faecalibacterium, and Blautia and increases in opportunists like..
Jan 9
2024
 Righi et al., Microorganisms, doi:10.3390/microorganisms12010131 Gut Microbiome Disruption Following SARS-CoV-2: A Review
Review of gut microbiome changes associated with COVID-19 during acute infection and post-acute COVID syndrome (PCS). Authors report increased opportunistic pathogens and reduced beneficial symbionts in acute COVID-19 lead to dysbiosis an..
Jan 5
2024
 Petrariu et al., Frontiers in Microbiology, doi:10.3389/fmicb.2023.1296447 Role of probiotics in managing various human diseases, from oral pathology to cancer and gastrointestinal diseases
Review of the role of probiotics in managing various human diseases including potential benefits for COVID-19. Probiotics may help restore equilibrium in the gut microbiota disrupted by COVID-19. Probiotic consumption can reduce viral loa..
Jan 4
2024
 Kolesnyk et al., BMC Nutrition, doi:10.1186/s40795-023-00816-8 The role of nutritional support with probiotics in outpatients with symptomatic acute respiratory tract infections: a multicenter, randomized, double-blind, placebo-controlled dietary study
60% improved recovery (p=0.02) and 68% lower long COVID (p=0.008). RCT 73 outpatients with mild COVID-19 showing improved recovery and increased RBD/spike antibody response with 28 days of a multi-strain probiotic (Bifidobacterium (B.) lactis BI040, B. longum BL020, Lactobacillus (L) rhamnosus LR110, L. ..
Dec 7
2023
 Lau et al., The Lancet Infectious Diseases, doi:10.1016/S1473-3099(23)00685-0 A synbiotic preparation (SIM01) for post-acute COVID-19 syndrome in Hong Kong (RECOVERY): a randomised, double-blind, placebo-controlled trial
57% improved recovery (p<0.0001). RCT 463 patients with post-acute COVID-19 syndrome (PACS) showing that treatment with a synbiotic preparation (SIM01) containing probiotics and prebiotics was associated with alleviation of multiple PACS symptoms including fatigue, memory..
Nov 8
2023
 Bondareva et al., Cell Host & Microbe, doi:10.1016/j.chom.2023.10.007 Cross-regulation of antibody responses against the SARS-CoV-2 Spike protein and commensal microbiota via molecular mimicry
Analysis of the role of oral microbiota, particularly Streptococcus salivarius, in enhancing immune response against SARS-CoV-2. Authors show that several commensal bacteria express proteins that mimic the receptor binding domain of the s..
Nov 2
2023
 Sarlin et al., JAMA Network Open, doi:10.1001/jamanetworkopen.2023.40608 Streptococcus salivarius Probiotics to Prevent Acute Otitis Media in Children
33% fewer cases (p=1). RCT 827 children aged 1-6 years in daycare in Finland analyzing the effectiveness of daily Streptococcus salivarius K12 oral probiotic use for 6 months in preventing acute otitis media (AOM). The probiotic group did not have a significant..
Oct 31
2023
 Hazan et al., American Journal of Gastroenterology, doi:10.14309/01.ajg.0000950600.34429.5f Probiotics Counterfeit! Study Finds Most Labels Mislead Customers
Analysis of the probiotic content of foods finding that labels were often misleading. Of 26 probiotic foods tested, only 5 contained Bifidobacterium in sufficient concentration for exhibiting a therapeutic effect.
Oct 22
2023
 Hazan et al., ACG 2023 Probiotics Counterfeit! Study Finds Most Labels Mislead Customers
Analysis of 26 commercially available probiotics with labels indicating Bifidibacteria content, showing only five contained Bifidobacterium in sufficient concentration for a therapeutic effect, and showing presence of a pathogen in one pr..
Oct 22
2023
 Hazan et al., ACG 2023 Treatment with Ivermectin Increases the Population of Bifidobacterium in the Gut
Analysis of the effect of ivermectin on the gut microbiome, showing a significant increase in Bifidobacterium. Bifidobacterium plays a key role in the immune system, for example enhancing antibody production, facilitating the induction of..
Oct 20
2023
 Kobatake et al., Nutrients, doi:10.3390/nu15204458 Lactobacillus paragasseri SBT2055 Activates Plasmacytoid Dendritic Cells and Improves Subjective Symptoms of Common Cold in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Parallel-Group Comparative Trial
RCT showing benefits for the common cold with probiotic LG2055. This randomized, double-blind, placebo-controlled trial examined whether Lactobacillus paragasseri SBT2055 (LG2055) could suppress common cold symptoms by activating plasmacy..
Sep 30
2023
 Di Pierro et al., Minerva Medica, doi:10.23736/S0026-4806.23.08920-6 Role of S. salivarius K12 in the prevention of URTI and AGE in nursery-aged children
78% fewer cases (p=0.007). Retrospective study of 287 nursery school children in Italy, 186 treated with S. salivarius K12 probiotic. The probiotic group had significantly lower rates of COVID-19, bronchitis, sinusitis, and laryngitis as well as lower antibiotic us..
Aug 31
2023
 Taufer et al., Life, doi:10.3390/life13091847 The Role of Bifidobacterium in COVID-19: A Systematic Review
Review of studies investigating the relationship between the gut bacteria genus Bifidobacterium and COVID-19. Observational studies found that lower abundance of Bifidobacterium was associated with more severe COVID-19. Interventional stu..
Jul 15
2023
 Graydon et al., Current Research in Immunology, doi:10.1016/j.crimmu.2023.100064 High baseline frequencies of natural killer cells are associated with asymptomatic SARS-CoV-2 infection
Analysis of 88 COVID+ patients in the USA showing that a higher frequency of natural killer (NK) cells was associated with asymptomatic infection. Improved NK cell numbers and functioning has been shown for exercise [Oh], better sleep [Ir..
Jun 13
2023
 Hassan et al., Research Square, doi:10.21203/rs.3.rs-3049708/v1 The effects of probiotic Lactobacillus acidophilus and colchicine on the control of symptoms, duration, and disease progression of mild and moderate cases of COVID-19: A randomized controlled clinical trial
80% lower hospitalization (p=0.2) and 18% improved recovery (p=0.42). RCT 150 patients in Egypt showing no significant difference in outcomes with probiotic lactobacillus acidophilus, although hospitalization was 2% versus 10% for control. SOC included vitamin C, D, and zinc.
May 22
2023
 Tian et al., Frontiers in Nutrition, doi:10.3389/fnut.2023.1179432 Probiotics improve symptoms of patients with COVID-19 through gut-lung axis: a systematic review and meta-analysis
Systematic review and meta-analysis of 10 studies (8 RCTs and 2 retrospective studies) with 1,198 COVID-19 patients showing improved overall symptoms, reduced diarrhea duration, lower C-reactive protein levels, and shorter hospital stays ..
Apr 1
2023
 Reino-Gelardo et al., Nutrients, doi:10.3390/nu15071736 Effect of an Immune-Boosting, Antioxidant and Anti-Inflammatory Food Supplement in Hospitalized COVID-19 Patients: A Prospective Randomized Pilot Study
61% lower mortality (p=0.05). RCT 162 late stage (65% on oxygen) patients in Spain, 78 treated with probiotics, prebiotics, vitamin D, zinc, and selenium, showing lower mortality with treatment, statistically significant only within the patients with high severity at ..
Mar 31
2023
 Zhu et al., PLOS ONE, doi:10.1371/journal.pone.0278356 Safety and efficacy of probiotic supplements as adjunctive therapies in patients with COVID-19: A systematic review and meta-analysis
Systematic review and meta-analysis of 8 RCTs with 1,027 patients showing that early probiotic supplements in COVID-19 patients reduced risk of a composite clinical endpoint of escalation or mortality (ow certainty), diarrhea, and cough/d..
Jan 17
2023
 Catinean et al., Nutrients, doi:10.3390/nu15030488 Ongoing Treatment with a Spore-Based Probiotic Containing Five Strains of Bacillus Improves Outcomes of Mild COVID-19
40% improved recovery (p=0.008). Retrospective 60 patients in Romania taking probiotics and 60 matched controls, showing faster symptom resolution with the use of probiotics. Spore-based probiotic containing five strains of Bacillus.
Oct 6
2022
 Su et al., Gut Microbes, doi:10.1080/19490976.2022.2128603 Antibiotics and probiotics impact gut antimicrobial resistance gene reservoir in COVID-19 patients
Analysis of 142 hospitalized COVID-19 patients showing antibiotics further expanded the gut antimicrobial resistance gene (AMR) reservoir while probiotics (synbiotic formula SIM01) reduced AMR genes. At admission, antibiotic-naive COVID-1..
Sep 30
2022
 Neris Almeida Viana et al., Critical Reviews in Food Science and Nutrition, doi:10.1080/10408398.2022.2128713 Benefits of probiotic use on COVID-19: A systematic review and meta-analysis
51% improved recovery (p<0.0001). Systematic review and meta analysis showing significant improvement in symptoms with priobiotic treatment.
Sep 28
2022
 Di Pierro et al., Microorganisms, doi:10.3390/microorganisms10101926 Clinical Effects of Streptococcus salivarius K12 in Hospitalized COVID-19 Patients: Results of a Preliminary Study
62% lower mortality (p=0.17) and no change in ICU admission (p=1). RCT 50 hospitalized patients in Pakistan, 25 treated with S. salivarius K12, showing lower mortality with treatment, without statistical significance. There were more patients with higher oxygen requirements at baseline in the control gro..
Aug 24
2022
 Navarro-López et al., Medicine in Microecology, doi:10.1016/j.medmic.2022.100061 Oral intake of Kluyveromyces marxianus B0399 plus lactobacillus rhamnosus CECT 30579 to mitigate symptoms in COVID-19 patients: A randomized open label clinical trial
33% improved recovery (p=0.08). RCT with 24 probiotics and 15 control patients in Spain, showing lower overall symptoms and lower digestive symptoms with treatment. Kluyveromyces marxianus B0399 plus lactobacillus rhamnosus CECT 30579.
Aug 3
2022
 Rodriguez-Blanque et al., Frontiers in Nutrition, doi:10.3389/fnut.2022.962566 Evaluation of the effect of Loigolactobacillus coryniformis K8 CECT 5711 consumption in health care workers exposed to COVID-19
9% fewer cases (p=0.92). Prophylaxis RCT with 127 probiotics and 128 control healthcare workers in Spain, showing no significant difference in cases. There were only 4 cases. Severity information by arm is not provided. L. coryniformis K8 CECT 5711. Treatment may..
Aug 1
2022
 Trinchieri et al., Biomedicines, doi:10.3390/biomedicines10081851 Exploiting Bacteria for Improving Hypoxemia of COVID-19 Patients
78% lower mortality (p=0.28) and 78% improvement (p=0.0001). Retrospective COVID-19 patients requiring CPAP, 21 treated with SLAB51 probiotics and 15 control patients, showing improved outcomes with treatment, despite significantly lower blood oxygenation at baseline in the treatment group.
Jun 28
2022
 Saviano et al., Journal of Clinical Medicine, doi:10.3390/jcm11133758 COVID-19 Pneumonia and Gut Inflammation: The Role of a Mix of Three Probiotic Strains in Reducing Inflammatory Markers and Need for Oxygen Support
86% lower ICU admission (p=0.24) and 26% shorter hospitalization (p=0.52). RCT 80 COVID-19 interstitial pneumonia patients in Italy, 40 treated with probiotics, showing significantly reduced gut inflammatory markers with treatment, and lower ICU admission and mortality, without statistical significance. Bifidoba..
Mar 2
2022
 Zhang et al., Journal of Gastroenterology and Hepatology, doi:10.1111/jgh.15796 Gut microbiota-derived synbiotic formula (SIM01) as a novel adjuvant therapy for COVID-19: An open-label pilot study
67% improvement (p=0.06). Pilot study of probiotic SIM01 with 25 consecutive COVID-19 patients in Hong Kong and 30 control patients treated by a different team during the same time period, showing improved antibody formation, reduced viral load and pro-inflammator..
Jan 12
2022
 Santinelli et al., Frontiers in Nutrition, doi:10.3389/fnut.2021.756177 Oral Bacteriotherapy Reduces the Occurrence of Chronic Fatigue in COVID-19 Patients
54% improved recovery (p<0.0001). Retrospective 58 hospitalized patients, 24 receiving probiotics during hospitalization, showing significantly lower fatigue six months post discharge with treatment.
Jan 5
2022
 Wischmeyer et al., medRxiv, doi:10.1101/2022.01.04.21268275 Daily Lactobacillus Probiotic versus Placebo in COVID-19-Exposed Household Contacts (PROTECT-EHC): A Randomized Clinical Trial
33% fewer moderate/severe cases (p=0.15), 38% fewer symptomatic cases (p=0.02), 27% faster recovery (p=0.37), and 43% fewer cases (p=0.17). RCT 182 COVID-19 exposed patients, 91 treated with daily probiotic Lactobacillus rhamnosus GG starting a median of 3 days from exposure, showing lower symptomatic COVID-19 with treatment. There were no hospitalizations or deaths.
Jan 5
2022
 Fernández-Ferreiro et al., Nutrients, doi:10.3390/nu14010228 Effects of Loigolactobacillus coryniformis K8 CECT 5711 on the Immune Response of Elderly Subjects to COVID-19 Vaccination: A Randomized Controlled Trial
2% higher mortality (p=1), 38% slower recovery (p=0.56), 28% higher severe cases (p=0.75), and 2% more symptomatic cases (p=1). RCT 200 nursing home residents over 60 years old in Spain showing Loigolactobacillus coryniformis K8 probiotic administration enhanced IgG antibody response in subjects previously infected with SARS-CoV-2 and tended to improve IgA antibod..
Dec 31
2021
 Wang et al., Annals of Palliative Medicine, doi:10.21037/apm-21-3373 The efficacy of probiotics in patients with severe COVID-19
Retrospective 156 COVID-19 patients in China, showing that diarrhea was significantly more common in severe/critical cases, and for severe/critical patients experiencing diarrhea, the duration of diarrhea was shorter with probiotic treatm..
Nov 25
2021
 Bozkurt et al., International Journal of Immunopathology and Pharmacology, doi:10.1177/20587384211059677 Oral booster probiotic bifidobacteria in SARS-COV-2 patients
Small retrospective 44 hospitalized patients in Turkey, showing improved outcomes with probiotic bifidobacterium, however minimal group details are provided (for example, the age of the control patients is unknown), and no adjustments wer..
Oct 25
2021
 Leal-Martínez et al., International Journal of Environmental Research and Public Health, doi:10.3390/ijerph19031172 (date from preprint) Effect of a Nutritional Support System to Increase Survival and Reduce Mortality in Patients with COVID-19 in Stage III and Comorbidities: A Blinded Randomized Controlled Clinical Trial
86% lower mortality (p=0.03) and 57% lower ventilation (p=0.31). 80 patient RCT with 40 patients treated with a comprehensive regimen of nutritional support, showing significantly lower mortality with treatment. Treatment contained cholecalciferol, vitamin C, zinc, spirulina maxima, folic acid, glutami..
Oct 13
2021
 Ivashkin et al., Probiotics Antimicrob Proteins, doi:10.1007/s12602-021-09858-5 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
2% higher mortality (p=1), 18% lower ventilation (p=1), 27% lower ICU admission (p=0.77), and 5% faster recovery (p=0.47). 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
2021
 Rathi et al., Medicines, doi:10.3390/medicines8090047 A Randomized Controlled Trial of the Efficacy of Systemic Enzymes and Probiotics in the Resolution of Post-COVID Fatigue
89% improved recovery (p<0.0001). 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
2021
 Ceccarelli et al., Nutrients, doi:10.3390/nu13082898 Oxygen Sparing Effect of Bacteriotherapy in COVID-19
82% lower ICU admission (p=0.15). 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
2021
 Zhang et al., Therapeutic Advances in Gastroenterology, doi:10.1177/17562848211035670 Probiotics use is associated with improved clinical outcomes among hospitalized patients with COVID-19
14% shorter hospitalization (p=0.009), 14% faster recovery (p=0.02), and 17% faster viral clearance (p=0.001). Retrospective 375 patients in China, 179 treated with probiotics (Bifidobacterium, Lactobacillus, and Enterococcus), showing improved clinical outcomes with treatment.
Jun 30
2021
 Veterini et al., Indian Journal of Forensic Medicine & Toxicology, 15:2 Probiotics Intake as Adjunct Therapy for Infected Health-Care with SARS COV-2
29% faster viral clearance (p=0.22). 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
2021
 Wang et al., Front. Bioeng. Biotechnol., doi:10.3389/fbioe.2021.646184 Oropharyngeal Probiotic ENT-K12 Prevents Respiratory Tract Infections Among Frontline Medical Staff Fighting Against COVID-19: A Pilot Study
Prophylaxis RCT in China with 98 healthcare workers 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 7
2021
 Hegazy et al., British Journal of Nutrition, doi:10.1017/S0007114521001926 Beyond probiotic legend: ESSAP gut microbiota health score to delineate SARS-COV-2 infection severity
Analysis of 200 mild and moderate COVID-19 outpatients showing an association between higher ESSAP scores (measuring exercise, sugar and prebiotic consumption, sleep, and antibiotic use) and milder COVID-19 disease. Authors find increased..
Jun 1
2021
 Meskina et al., Therapeutic Archive, doi:10.26442/00403660.2021.04.200835 Efficiency of application of sorbed probiotics in complex therapy of pneumonia caused by SARS-CoV-2
RCT 100 pneumonia patients in Russia, showing faster symptom resolution with probiotic treatment (B. bifidum 1).
May 31
2021
 Ahanchian et al., Open Journal of Nursing, doi:10.4236/ojn.2021.115025 Synbiotic for Prevention of SARS-Cov2 Infection in High Risk Hospital Staffs: A Randomized Controlled Trial
73% fewer symptomatic cases (p=0.35) and 85% fewer cases (p=0.24). 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
2021
 Gutiérrez-Castrellón et al., Gut Microbes, doi:10.1080/19490976.2021.2018899 (date from preprint) Probiotic improves symptomatic and viral clearance in Covid19 outpatients: a randomized, quadruple-blinded, placebo-controlled trial
35% improved recovery (p<0.0001). 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
2021
 Di Pierro, F., Minerva Medica, doi:10.23736/S0026-4806.20.06570-2 A possible probiotic (S. salivarius K12) approach to improve oral and lung microbiotas and raise defenses against SARS-CoV-2
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 30
2021
 Holt et al., Thorax, doi:10.1136/thoraxjnl-2021-217487 Risk factors for developing COVID-19: a population-based longitudinal study (COVIDENCE UK)
30% fewer cases (p=0.11). Prospective survey-based study with 15,227 people in the UK, showing lower risk of COVID-19 cases with vitamin A, vitamin D, zinc, selenium, probiotics, and inhaled corticosteroids; and higher risk with metformin and vitamin C. Statistica..
Mar 29
2021
 Haran et al., medRxiv, doi:10.1101/2021.03.26.21254422 Targeting the Microbiome With KB109 in Outpatients with Mild to Moderate COVID-19 Reduced Medically Attended Acute Care Visits and Improved Symptom Duration in Patients With Comorbidities
50% fewer combined hospitalization/ER visits (p=0.13) and 20% faster recovery (p=0.1). RCT 350 COVID+ outpatients in the USA, 174 treated with prebiotic KB109 (a microbiome metabolic therapy candidate), showing lower combined hospitalization, ER, and urgent care visits with treatment. NCT04414124.
Mar 19
2021
 Kurian et al., Archives of Medical Research, doi:10.1016/j.arcmed.2021.03.002 Probiotics in Prevention and Treatment of COVID-19: Current Perspective and Future Prospects
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
2021
 Di Pierro et al., Minerva Medica, doi:10.23736/S0026-4806.21.07487-5 The administration of S. salivarius K12 to children may reduce the rate of SARS-CoV-2 infection
98% fewer cases (p<0.0001). 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
2021
 Li et al., International Immunopharmacology, doi:10.1016/j.intimp.2021.107531 The role of probiotics in coronavirus disease-19 infection in Wuhan: A retrospective study of 311 severe patients
12% lower hospital discharge (p=0.68) and 35% slower viral clearance (p=0.001). 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
2021
 Singh et al., Nutrition Research, doi:10.1016/j.nutres.2020.12.014 Probiotics: A potential immunomodulator in COVID-19 infection management
Review of studies supporting the use of probiotics for respiratory infections and identification of microbial strains potentially beneficial for COVID-19.
Feb 2
2021
 Shah et al., Advances in Clinical Toxicology, doi:10.23880/act-16000204 Potential of the Combination of a Systemic Enzyme Complex and Probiotics administration to Combat COVID-19: A Randomized Open Label Prospective Analysis
11% faster recovery (p=0.19) and 11% shorter hospitalization (p=0.18). 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
2021
 Ceccarelli et al., Frontiers in Medicine, doi:10.3389/fnut.2020.613928 Oral Bacteriotherapy in Patients With COVID-19: A Retrospective Cohort Study
64% lower mortality (p=0.003) and 15% lower ICU admission (p=0.6). Retrospective 200 severe condition hospitalized patients in Italy, 88 treated with probiotic Sivomixx, showing lower mortality with treatment.
Dec 15
2020
 Stavropoulou et al., Frontiers in Nutrition, doi:10.3389/fnut.2020.614986 Probiotics as a Weapon in the Fight Against COVID-19
Review of the potential benefits of probiotics for COVID-19.
Nov 30
2020
 Louca et al., BMJ Nutrition, Prevention & Health, doi:10.1136/bmjnph-2021-000250 (date from preprint) Modest effects of dietary supplements during the COVID-19 pandemic: insights from 445 850 users of the COVID-19 Symptom Study app
8% fewer cases (p=0.03). 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
2020
 Olaimat et al., npj Science of Food, doi:10.1038/s41538-020-00078-9 The potential application of probiotics and prebiotics for the prevention and treatment of COVID-19
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
2020
 d'Ettorre et al., Frontiers in Medicine, doi:10.3389/fmed.2020.00389 Challenges in the Management of SARS-CoV2 Infection: The Role of Oral Bacteriotherapy as Complementary Therapeutic Strategy to Avoid the Progression of COVID-19
87% lower mortality (p=0.14) and 88% lower progression (p=0.01). Retrospective 70 hospitalized patients in Italy, 28 treated with probiotic Sivomixx, showing lower risk of respiratory failure and faster recovery with treatment.
May 8
2020
 Baud et al., Frontiers in Public Health, doi:10.3389/fpubh.2020.00186 Using Probiotics to Flatten the Curve of Coronavirus Disease COVID-2019 Pandemic
Review of data supporting the use of probiotics for COVID-19 and mechanisms of action.
Jul 31
2019
 Finamore et al., Nutrition, doi:10.1016/j.nut.2019.02.005 Supplementation with Bifidobacterium longum Bar33 and Lactobacillus helveticus Bar13 mixture improves immunity in elderly humans (over 75 years) and aged mice
RCT 98 adults, showing that probiotics improved immune function including increased natural killer (NK) cell activity. [Graydon] showed that a lower frequency of natural killer cells was associated with symptomatic COVID-19 infection.
Feb 3
2015
 Hao et al., Cochrane Database of Systematic Reviews, doi:10.1002/14651858.CD006895.pub3 Probiotics for preventing acute upper respiratory tract infections
Meta analysis of 12 RCTs with 3,720 patients showing probiotics reduced acute upper respiratory tract infections.
References