Table 4.

List of clinical trials initiated to understand the role of gut microbiota in coronavirus disease 2019 and its therapeutic implications

SI. No.	Objective of clinical trials	Clinical trials No.	Description of clinical trials	Remarks
1	Evaluate the combination of probiotics (P. acidilactici and L. plantarum) to reduce the viral load of moderate or severe COVID-19 patients	NCT04517422	It was a randomized controlled trial, 300 participants, treatment by dietary supplement (probiotics)	Observational study of adult and older adult, trial completed
2	To explore the natural history of mild-to-moderate COVID-19 illness and safety of a novel glycan (KB109) and self-supportive care	NCT04414124	It was a randomized, prospective, open-label, parallel-group controlled clinical study of 350 participants	Observational study of adults (both male and female), trial completed
3	Investigate the physiologic effects of the novel glycan (KB109) on patients with COVID-19 illness on gut microbiota structure and function in the outpatient	NCT04486482	It was a randomized, open-label clinical study of 49 participants	Observational study of adults patients with mild-to-moderate COVID-19 infections, trial completed
4	Evaluate the clinical contribution of the gut microbiota and its diversity on the COVID-19 disease severity and the viral load	NCT05107245	It was case-control, diagnostic study of 143 participants	Observational study on the diagnostic evaluation of the human intestinal microbiota, trial completed
5	Studied the effects of Lactobacillus coryniformis K8 intake on the prevalence and severity of COVID-19 in health professional	NCT04366180	A randomized, interventional study of 314 participants	Investigation of probiotic effects to healthcare personnel exposed to COVID-19 infection
6	Investigate to exploring the role of nutritional support by probiotics to COVID-19 outpatients (adult)	NCT04907877	Randomized, evidence based study of 300 participants	Used of probiotics as dietary supplement that enhance specific immune response of patients having COVID-19 respiratory infection
7	Use of dietary supplement (Omni-Biotic® 10 AAD) can decrease the intestinal inflammation and improves dysbiosis for COVID-19 patients	NCT04420676	It was a randomized Interventional study of 30 participants	This study performed as double blind, placebo-controlled study
8	Evaluate the probiotics efficacy to decrease the COVID-19 infection symptoms and duration of COVID-19 positive patients	NCT04621071	The double-blind, randomized, controlled trial of 17 participants	This study performed to explored the effects of dietary supplement: Probiotics (2 strains 10 × 109 UFC), trial completed
9	Impact analysis of probiotic strain L. reuteri DSM 17938 for specific Abs response against SARS-CoV-2 infection	NCT04734886	It was control, randomized trial of 161 participants	To assess the upon and after COVID-19 infection in healthy adults, trial completed
10	To evaluate the primary efficacy of live microbials (probiotics) for boosting up the immunity of SARS-CoV-2 infected persons (unvaccinated)	NCT04847349	It was double-blind, randomized, controlled trial of 54 participants	Efficacy analysis of dietary supplement (combination of live microbials) as anti COVID-19 infection, trial completed
11	Evaluate the follow -up of Symprove (probiotic) to COVID-19 positive patients	NCT04877704	The randomized clinical trial was performed with 60 patients	Observational study to supervision of hospitalized COVID-19 patients
12	Study was performed to evaluate the possible effect of a probiotic mixtures in the improvement of COVID-19 infection symptoms	NCT04390477	It was randomized case control, clinical trial of 41 participants	Observational study of dietary supplement: Probiotic to COVID-19 patients
13	The probiotic ( Omni-Biotic Pro Vi 5) use for investigate the side effect of post-COVID syndrome	NCT04813718	It was a randomized trial of 20 participants	It was a therapeutic target study of probiotic for treatment of acute COVID-19 and prevention of post COVID infections
14	To evaluate the effect of a probiotic strain on the occurrence and severity of COVID-19 in hospitalised elderly population	NCT04756466	Randomized control trial of 201 participants	It was observational study, probiotic sued for improve the immune response of elderly patients
15	This study assesses the beneficial effects of the nutritional supplementation (ABBC1) to individuals taken the COVID-10 vaccine	NCT04798677	It was a double-blinded, placebo-controlled, randomized clinical study of 90 participants	Used as knowing the microbiome modulating properties, observational study
16	To investigate the consequence of Ligilactobacillus salivarius MP101 to hospitalised elderly individuals	NCT04922918	Non-randomised study of 25 participants	Observational study of aged patients having highly affected by COVID-19
17	Study was performed to explored the effect of the probiotic Lactobacillus rhamnosus GG	NCT04399252	It was a randomized double-blind, placebo-controlled trail of 182 participants	Observational study of individuals microbiome of household contacts exposed to COVID-19
18	Treatment approaches by probiotics to human gut microbiome and growing the anti-inflammatory response for COVID-19 infected patients	NCT04854941	It was a randomized controlled open-label study of 200 participants	The optimizing treatment approaches based observational study, trial completed
19	To evaluate the capability of the novel nutritional supplement (probiotics and other vitamins) to COVID-19 infected and hospitalised patients	NCT04666116	Randomized, single blind clinical trial of 96 participants	Used of dietary supplementation with probiotics aims to reduce the viral load
20	Using of probiotics for COVID 19 transmission reduction to health care professionals	NCT04462627	It was a non-randomized trial of 500 participants	Analysis and reduction of COVID-19 viral load to health care professionals

P. acidilactici: Pediococcus acidilactici; L. plantarum: Lactobacillus plantarum; COVID-19: Coronavirus disease 2019; SARS-CoV-2: Severe acute respiratory syndrome coronavirus 2.