Fermented dairy product and bifidobacteria diversity in adults

Inclusion Criteria:

1. Male and female subjects aged between 45 and 60 years old.
2. BMI between 18.5 kg/m² and 30 kg/m².
3. Subjects who are overtly healthy as determined by the investigator.
4. Able to speak and read in French.
5. Willing and able to collect their faecal samples themselves.
6. Having access to adequate space to store the investigational.
7. Regular bowel movements.
8. Willing to consume the study products twice per day for 28 consecutive days.
9. Willing not to consume any fermented dairy products during the entire study, other than the study products.
10. Willing not to consume any probiotic, prebiotic or synbiotic supplements during the entire study.
11. Willing to limit alcohol consumption during the study.
12. Willing not to smoke tobacco during the study.
13. Willing not to use any soft or hard drug during the study.
14. Signed written informed consent by the participant.
15. Female subjects must either be postmenopausal for at least 12 months or have undergone specific surgical procedures resulting in sterility or they are using one of the medically approved contraceptive methods.
16. Subject is covered by French health insurance.
17. Subject agrees to be registered in the national database of subjects participating in clinical research.
18. Subject is willing and able to complete the electronic Patient Reported Outcomes using their own digital device having access to internet.

Exclusion Criteria:

1. Any ongoing metabolic disease, hypertension, inflammatory disease, thyroid disease, allergic conditions requiring chronic systemic medication, psychiatric disorder, gastrointestinal disorder, chronic pain, or neurological disorder diagnosed by a physician.
2. Known with allergy or intolerance to any ingredients or allergens.
3. Pregnancy or breast-feeding at the screening visit or plan for pregnancy during the study.
4. Any antecedents of digestive surgery, or plan for such surgery during the study.
5. Any dental surgery within the last 4 weeks before the screening visit, or plan for dental surgery during the study.
6. Subject who had any surgery or intervention requiring a general anaesthesia in the preceding 4 weeks before the screening visit, or who plans to have one during the study.
7. Unable (or unwilling) to adhere to protocol requirements.
8. Subject with a special diet at the screening visit, or plan for such diet during the study.
9. Major changes in subject's dietary habits ≤ 4 weeks before the screening visit or plan for such major changes during the study including change in vitamin or mineral supplements use, but except for dietary restrictions related to the study.
10. Enhanced diet together with intense physical activity ≤ 4 weeks before the screening visit, plan for such a diet and training during the study, or plan for major changes in physical activity during the study.
11. Use ≤ 8 weeks before the screening visit or plan of use during the study of systemic medication that can affect the gastrointestinal function or plan of use during the study (if needed, incidental use of ≤ 4 tablets of paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs) or aspirin per 2-week period is allowed.
12. Excessive alcohol consumption during the past 6 months before the screening visit.
13. Active smoker, or quit active smoking less than 5 years ago before the screening visit. Not regularly smoking is allowed.
14. Drug abuse based on investigator's judgement.
15. Participation in another study with investigational or marketed products potentially affecting the gut microbiota ≤ 4 weeks before the screening visit or plan for participation in any other intervention study during the study.
16. Living in the same home as others already participating in the study and to concomitantly receive some study products.
17. Subject under guardianship, curatorship, person under judicial protection, family empowerment or future protection mandate.
18. Employees, family members or other relatives of employees of the participating centre or of Danone Global Research \& Innovation Center.
19. Subject's total compensation for participation in clinical studies within the past 12 months, including the compensation expected from the Mellifera study, would exceed the annual ceiling of €6,000.