The main objective of this project is to evaluate the absence of adverse gastrointestinal effects following the consumption of a daily probiotic capsule during 15 days.

The secondary objective of this study is to verify the absence of any adverse effects other than gastrointestinal ones following the daily consumption of a probiotic during 15 days in a healthy population.

Specific objectives are:

• To evaluate changes in gastrointestinal health through self-reported questionnaire.
• To determine the adherence to probiotic consumption.
• To analyse headache, tiredness/fatigue, muscle or joint pain, fever or low-grade fever, chills, allergic reactions, difficulty sleeping, dizziness and general discomfort by General Adverse Effects Questionnaire.

Target sample size is 20 subjects.

Participants will be allocated in one group (experimental group).

Participants will visit nutritional intervention unit at Clinical Investigation Day 1 (day 1) and at Clinical Investigation Day 2 (day 15).

Volunteers who wish to participate in the study will complete an online questionnaire to verify the main inclusion criteria. Those who meet the criteria will be invited to an information and screening visit to address any questions. Volunteers who agree to participate will sign the informed consent form.

During the intervention, participants will attend two clinical investigation visits. The first Clinical Investigation Day will be conducted on the same day as the screening, and the second Clinical Investigation Day will take place at the end of the 15-day period. In both visits, anthropometric measurements, gastrointestinal symptoms and a general questionnaire on adverse effects will be recorded. Volunteers will be required to consume one probiotic capsule per day during 15 days.

Inclusion Criteria:

• Healthy men and women aged between 18 and 70 years.
• Stable body weight (±5%) during the three months prior to study initiation.
• Physical examination and vital signs within normal limits or clinically irrelevant for the study.
• Subjects must be able to understand and willing to sign the informed consent form, and comply with all study procedures and requirements.
• Ongoing pharmacological/hormonal treatment will be permitted provided it does not affect the parameters under investigation and the dosage has been stable for at least three months prior to study initiation.
• Willingness to undergo all study procedures, including daily consumption of one probiotic capsule during the intervention.
• Availability in terms of time and location to attend the two scheduled in-person clinical evaluation sessions.

Exclusion Criteria:

• Volunteers undergoing pharmacological treatment with unstable dosing (less than 3 months prior to study initiation) will be excluded, particularly if treatments:
• Affect gastrointestinal function.
• Include chronically prescribed stomach protectants.
• Subjects with significant functional or structural abnormalities of the digestive system, such as malformations, angiodysplasias, active peptic ulcers, chronic inflammatory or malabsorption diseases, hiatal hernia, chronic reflux, etc.
• Subjects who have undergone surgical procedures resulting in permanent alterations of the digestive system (e.g., gastroduodenostomy) or bariatric surgery.
• Presence of systemic intestinal, hepatic, or renal diseases, such as uncontrolled thyroid disorders, cirrhosis, inflammatory bowel disease, untreated anemia, etc. (non-alcoholic fatty liver disease will not be excluded).
• Alcohol consumption exceeding the sex-specific limits (>14 units/week for women, >20 units/week for men).
• Pregnancy, lactation, or plans to become pregnant during the study period.
• Use of nutritional supplements that may affect study outcomes (e.g., weight-loss supplements, newly initiated fiber supplements, probiotics, postbiotics, etc.).
• Subjects with any type of cancer currently undergoing treatment, or with less than five years since cancer remission.
• Known allergy to any component of the investigational product.
• Presence of cognitive and/or psychological impairments.
• Anticipated poor compliance or, in the investigator's opinion, difficulty adhering to study procedures.
• Participation in any weight loss or body composition modification treatments.
• Use of antibiotics within 15 days prior to the baseline visit.