To investigate the safety and tolerability of BL-001 in healthy volunteers for 28 consecutive days.

This is a Phase 1a randomized, parallel-group, double-blind, placebo-controlled, single-center, multiple dose study to evaluate the safety and tolerability of BL-001.

Key Inclusion criteria

1. Informed consent: signed written informed consent before inclusion in the study
2. Sex and Age: men/women, 18-55 years old inclusive
3. Body Mass Index (BMI): 18.5-30 kg/m2 inclusive
4. Vital signs: systolic blood pressure 100-139 mmHg, diastolic blood pressure 50-89 mmHg, heart rate 50-90 bpm, measured after 5 min at rest in the sitting position
5. Full comprehension: ability to comprehend the full nature and purpose of the study, including possible risks and side effects; ability to co-operate with the investigator and to comply with the requirements of the entire study
6. Contraception and fertility (women only): women of child-bearing potential must be using at least one of the protocol defined and reliable methods of contraception

Key Exclusion criteria

1. Electrocardiogram 12-leads (supine position): clinically significant abnormalities
2. Physical findings: clinically significant abnormal physical findings which could interfere with the objectives of the study
3. Bowel movements: on average ≥3 stools per day or <3 stools per week
4. Laboratory analyses: clinically significant abnormal laboratory values indicative of physical illness
5. Allergy: ascertained or presumptive hypersensitivity to the formulation's ingredients; history of anaphylaxis to drugs or allergic reactions in general, which the Investigator considers may affect the outcome of the study
6. Diseases: significant history of renal, hepatic, gastrointestinal, cardiovascular, respiratory, skin, hematological, endocrine, psychiatric or neurological diseases that may interfere with the aim of the study
7. Gastrointestinal: evidence of acute or chronic gastrointestinal disorders
8. Medications and probiotics: probiotics, nutraceuticals, and medications, including over the counter medications and herbal remedies for 2 weeks and antibiotics for 3 months before the start of the study. Hormonal contraceptives for women will be allowed

Both the Investigator and the subjects are not aware of the treatment administered.