Efficacy, safety and acceptability of a probiotic with Bacillus coagulans on immunomodulation in healthy volunteers: a randomized, double-blind, placebo-controlled pilot study
| ISRCTN | ISRCTN16720091 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN16720091 |
| Secondary identifying numbers | MTH-NUT0121 |
- Submission date
- 06/11/2025
- Registration date
- 06/11/2025
- Last edited
- 06/11/2025
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Other
Plain English summary of protocol
Background and study aims
This study looked at whether taking a daily probiotic supplement could help support the immune system and improve overall wellbeing in healthy adults. The probiotic being tested contains Bacillus coagulans, a type of friendly bacteria. Researchers also wanted to check how safe and acceptable the supplement is compared to a placebo (a capsule with no active ingredients).
Who can participate?
The study invited healthy men and women aged 18 to 65 who eat a balanced diet, exercise regularly, and don’t have any long-term illnesses or immune-related conditions.
What does the study involve? (for participants)
People who joined the study were randomly given either the probiotic or a placebo capsule to take once a day for 90 days. They visited the clinic twice—once at the start and once at the end of the 90 days. At each visit, a small blood sample was taken to measure immune system markers, and participants filled out a questionnaire about their quality of life. Around halfway through the study, there was a short phone call to check how things were going and ask about any side effects.
What are the possible benefits and risks of participating?
Participants might experience better wellbeing and improved immune function, although this isn’t guaranteed. The risks were very low and mostly limited to mild digestive discomfort.
Where is the study run from?
The study was led by two dermatologists, Dr Marina Corral and Dr Nuria Setó Torrent, at Hospital Universitari Sagrat Cor in Barcelona, Spain. It was coordinated by Methodex S.L., also based in Barcelona.
When is the study starting and how long is it expected to run for?
April 2021 to December 2022
Who is funding the study?
The study was sponsored by Nutris Ingredients S.L., a company based in Madrid, Spain.
Who is the main contact?
Dr Marina Corral, marina.corral@clinicadiagonal.com
Dr Nuria Setó Torrent, nurisetorrent@gmail.com
Contact information
Public, Scientific
Calle Marzo 58
Madrid
28022
Spain
 ORCID ID |
0000-0002-9738-608X |
|---|---|
| Phone | +34 692911819 |
| vgallo@nutris.es |
Principal investigator
CM Tarradellas. Av. de Josep Tarradellas, 33, Sants-Montjuïc
Barcelona
08029
Spain
| Phone | +34 637524625 |
|---|---|
| marina.corral@clinicadiagonal.com |
Principal investigator
Centro Mèdico FIATC Tarradellas. Av de Josep Tarradellas, 33
Barcelona
08029
Spain
| ORCID ID |
0000-0001-7922-9905 |
|---|---|
| Phone | +34 607488717 |
| nurisetorrent@gmail.com |
Study information
| Study design | Randomized placebo-controlled double-blind parallel groups (1:1 allocation) |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Randomised controlled trial |
| Study setting(s) | Hospital |
| Study type | Efficacy, Quality of life, Safety |
| Scientific title | Prospective, double-blind, randomized, single-center pilot clinical study compared with placebo, to assess efficacy, safety and acceptability of a probiotic with Bacillus coagulans on immunomodulation in healthy volunteers |
| Study objectives | The main objective of this study was to assess the efficacy, safety, and acceptability of an oral probiotic containing Bacillus coagulans on Immunomodulation in healthy adults compared with placebo. Primary hypothesis: Oral administration of Bacillus coagulans exerts an immunomodulatory effect compared with placebo. Secondary hypotheses: Oral administration of Bacillus coagulans improves quality of life and it is safe and well-tolerated without adverse effects compared with placebo. |
| Ethics approval(s) |
Approved 14/09/2021, CEIm Grupo Hospitalario Quirónsalud-Catalunya (Carrer de Pedro i Pons, 1, Sant Cugat del Vallès, Barcelona, 08195, Spain; +34 935656000; ceic.idcsa.cat@idcsalud.es), ref: 2021/81-DER-HUSC |
| Health condition(s) or problem(s) studied | Immune modulation and quality of life in healthy adults. |
| Intervention | Participants are randomly assigned (1:1) to receive either the probiotic product or a placebo for 90 days. The experimental group receives one oral capsule daily before meals containing Bacillus coagulans (5×10^9 CFU/day). The control group receives one identical placebo capsule daily with the same appearance and schedule. All participants attend two on-site visits (Day 1 and Day 90) at Hospital Universitari Sagrat Cor for blood sample collection and quality-of-life assessment. A telephone follow-up is performed at mid-study (around Day 45) to monitor adherence and safety. The randomisation process was computer-generated using R statistical software (RStudio) prior to enrolment. Participants were then assigned in a 1:1 ratio to either the probiotic or placebo group according to this pre-established randomisation list. The allocation was implemented by the CRO (Methodex SL), ensuring double-blind conditions for investigators and participants throughout the study. |
| Intervention type | Supplement |
| Primary outcome measure | Levels of immunological markers (immunoglobulin A [IgA], immunoglobulin G [IgG], interferon-γ [IFN-γ], and total leukocyte count) measured by blood analysis at baseline (Day 1) and after 90 days of supplementation (Day 90) |
| Secondary outcome measures | 1. Health-related quality of life measured using the SF-36 questionnaire at baseline (Day 1) and after 90 days of supplementation (Day 90) 2. Safety and tolerability assessed through participant reports and clinical evaluation at each visit and via follow-up phone call (around Day 45) |
| Overall study start date | 27/04/2021 |
| Completion date | 29/12/2022 |
Eligibility
| Participant type(s) | Healthy volunteer |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 65 Years |
| Sex | All |
| Target number of participants | 62 |
| Total final enrolment | 55 |
| Key inclusion criteria | 1. Healthy male and female volunteers aged 18–65 years 2. Individuals following a balanced diet according to standard nutritional guidelines 3. Participants performing at least 30 minutes of daily physical activity 4. Good personal hygiene and general health status 5. No psychological or psychiatric disorders 6. No family history of genetically heritable diseases 7. Able to understand the study information and comply with study requirements 8. Willing to provide written informed consent before participation |
| Key exclusion criteria | 1. Diagnosis of diabetes mellitus 2. Pregnant or breastfeeding women 3. Presence of autoimmune disease (e.g. Addison’s disease, celiac disease, Graves’ disease, Hashimoto’s thyroiditis, rheumatoid arthritis, multiple sclerosis, systemic lupus erythematosus, type I diabetes, etc.) 4. Current or recent treatment with immunosuppressive drugs 5. Presence of any chronic disease or acute respiratory infection (including common cold, flu, or COVID-19). 6. Use of antibiotics within 10 days prior to study start 7. Intake of probiotics or immune-boosting supplements (e.g. vitamin C, echinacea, royal jelly, multivitamins) within 10 days prior to study start 8. History of drug, alcohol, or substance abuse 9. Participation in another clinical trial within the previous 3 months 10. Any medical or social condition that, in the investigator’s opinion, could interfere with study participation or data reliability |
| Date of first enrolment | 17/11/2021 |
| Date of final enrolment | 29/03/2022 |
Locations
Countries of recruitment
- Spain
Study participating centre
Barcelona
08029
Spain
Sponsor information
Industry
Calle Marzo 58
Madrid
28022
Spain
| Phone | +34 910325627 |
|---|---|
| info@nutris.es | |
| Website | www.nutris.es |
Funders
Funder type
Not defined
No information available
Results and Publications
| Intention to publish date | 30/06/2026 |
|---|---|
| Individual participant data (IPD) Intention to share | Yes |
| IPD sharing plan summary | Available on request |
| Publication and dissemination plan | Planned publication in a peer-reviewed journal. |
| IPD sharing plan | The datasets generated during and/or analysed during the current study will be available upon request from Veronica Gallo (vgallo@nutris.es). |
Editorial Notes
06/11/2025: Trial's existence confirmed by CEIm Grupo Hospitalario Quirónsalud-Catalunya.
