There has been a flood of suggestions over the last year for COVID-19. In general, the suggestions are believers in some cure-all supplements, preaching their gospels. The more responsible one register trials and start (example).
The following are what has studies supporting some speculations.
- Oral Bacteriotherapy in Patients With COVID-19: A Retrospective Cohort Study 
- ” the estimated risk of developing respiratory failure was eight-fold lower in patients also receiving oral bacteriotherapy… (Sivomixx® a multi-strain product containing five strains of lactobacilli, two strains of bifidobacteria, and one strain of Streptococcus thermophilus) “
- Challenges in the Management of SARS-CoV2 Infection: The Role of Oral Bacteriotherapy as Complementary Therapeutic Strategy to Avoid the Progression of COVID-19 
- “The formulation administered in this study contained: Streptococcus thermophilus DSM 32345, L.acidophilus DSM 32241, L. helveticus DSM 32242, L. paracasei DSM 32243, L. plantarum DSM 32244, L. brevis DSM 27961, B. lactis DSM 32246, B. lactis DSM 32247. Ormendes SA, Lausanne, Switzerland which gifted the product Sivomixx® (SivoBiome® in USA)”
- Effectiveness of In-Hospital Cholecalciferol Use on Clinical Outcomes in Comorbid COVID-19 Patients: A Hypothesis-Generating Study 
- “a significant predictive power of the four variables: (a) low (<50 nmol/L) 25(OH) vitamin D levels, (b) current cigarette smoking, (c) elevated D-dimer levels (d) and the presence of comorbid diseases”
- “Little evidence from observational studies and trials to date have evaluated the effect of high-dose cholecalciferol[Vitamin D] in hospitalized COVID-19 patients.” i.e.
- “Results from this retrospective analysis demonstrate that two consecutive doses of 200,000 IU cholecalciferol (total of 400,000 IU) can significantly improve the outcome in patients affected by COVID-19 that are also burdened with three or more comorbid diseases. “
- Vitamin D Insufficiency and Deficiency and Mortality from Respiratory Diseases in a Cohort of Older Adults: Potential for Limiting the Death Toll during and beyond the COVID-19 Pandemic? 
- 25-Hydroxyvitamin D Concentrations Are Lower in Patients with Positive PCR for SARS-CoV-2 
- Influence of aluminum salts on COVID-19 infected patients 
- “As a result, it has been observed that aluminum salts have beneficial effects both clinically and in the laboratory on COVID-19 infected cases.”
- Intermediate-dose anticoagulation, aspirin, and in-hospital mortality in COVID-19: a propensity score-matched analysis 
- “in-hospital aspirin compared to no antiplatelet therapy was associated with a significantly lower cumulative incidence of in-hospital death’
- Neutrophil more than platelet activation associates with thrombotic complications in COVID-19 patients  Aspirin mainly affects platelet activation
- “SARS-CoV-2 patients with acute respiratory distress syndrome show elevated fibrinogen activity, high D-dimer levels and maximum amplitude of clot strength. Platelet count, fibrinogen, and standard coagulation tests do not indicate a disseminated intravascular coagulation. ” 
- “the fibrinogen values in patients were higher than the control group (p < 0.05). ” 
- Piracetam (where available) may lower fibrinogen levels
- Inhibitory effect of piracetam on platelet-rich thrombus formation in an animal model 
- “a reduction of 30-40% in the plasma concentrations of fibrinogen and von Willebrand’s factor.” 
- Tumeric with black pepper: An hydroalcoholic extract of Curcuma longa [Turmeric] lowers the abnormally high values of human-plasma fibrinogen 
If you know of any other solid studies, please email or add as a comment.