For an Investigator-led Hair Study Comparing Between Healthy and Hair Loss Volunteers

1. Male volunteer from 21 to 45 years old
2. Volunteer with BMI between 18.5 to 30 kg/m2
3. Volunteer willing and able to fulfill the study requirements and schedule
4. Volunteer willing to give their stool sample, as well as swabs, follicles, and blood.
5. Volunteer informed about the study objectives and procedures, and able to understand them
6. Volunteer who has given written informed consent

Volunteers in the healthy control panel must satisfy the following criteria:

1. Volunteer in overall good health
2. Volunteer with no diagnosis of hair loss or other condition or treatment susceptible to impact hair count and microbiome.

Volunteers in the AGA panel must satisfy the following criteria:

1. Volunteer diagnosed with Androgenetic Alopecia grade III Vertex to V on the Hamilton-Norwood scale
2. Volunteer willing to restrain from the use of any additional hair loss oral and topical pharmaceuticals (ex: topical minoxidil) over the course of the study
3. Volunteer eligible to undergo oral minoxidil treatment, with no contra-indication

Exclusion Criteria:

1. Volunteer with severe gastro-intestinal symptoms (including gluten and lactose intolerance)
2. Volunteer with auto-immune disease, diabetes; hyper or hypo-thyroidism ; chronic kidney failure
3. Volunteer with diagnosis of scalp-related disease such as folliculitis, lichen planopilaris, folliculitis decalvans, tinea capitis, head lice, or seborrheic dermatitis
4. Volunteer undergoing hypertension treatment
5. Volunteer who undertook any oral anti-hair loss pharmaceutical treatment in the past 3 months (e.g. Finasteride)
6. Volunteer who undertakes any hormone-disrupting drug
7. Volunteer who used topical minoxidil or other pharmaceutical-grade topical hair restorers in the past 3 months
8. Volunteer with a total dandruff score above 1 on the L'Oreal Dandruff scale.
9. Volunteer who used perms or hair dyes in the past 2 months
10. Volunteer who underwent scalp reduction or hair transplant procedures
11. Volunteer who declares to be deprived of freedom by administrative or legal decision
12. Volunteer who cannot be contacted by phone in case of emergency
13. Volunteer having currently participating in another clinical study
14. Volunteer who used antibiotics or antifungal medication (topical to scalp and systemic) in the past 4 weeks
15. Volunteer who used probiotics supplements in the past 4 weeks. (dietary probiotics such as yogurt, kefir, and kimchi are acceptable)
16. Volunteer who follows a non-conventional diet (e.g. vegan, ketogenic, strict intermittent fasting diets)

Non-inclusion Criteria:

1. Volunteer diagnosed with HIV, Hepatitis C, Hepatitis B
2. Volunteer with severe gastro-intestinal symptoms (including gluten and lactose intolerance)
3. Volunteer with auto-immune disease, diabetes; hyper or hypo-thyroidism ; chronic kidney failure
4. Volunteer with diagnosis of scalp-related disease such as folliculitis, lichen planopilaris, folliculitis decalvans, tinea capitis, head lice, or seborrheic dermatitis
5. Volunteer undergoing hypertension treatment
6. Volunteer who undertook any oral anti-hair loss pharmaceutical treatment in the past 3 months (e.g. Finasteride)
7. Volunteer who undertakes any hormone-disrupting drug
8. Volunteer who used topical minoxidil or other pharmaceutical-grade topical hair restorers in the past 3 months
9. Volunteer with a total dandruff score above 1 on the L'Oreal Dandruff scale.
10. Volunteer who used perms or hair dyes in the past 2 months
11. Volunteer who underwent scalp reduction or hair transplant procedures
12. Volunteer who declares to be deprived of freedom by administrative or legal decision
13. Volunteer who cannot be contacted by phone in case of emergency
14. Volunteer having currently participating in another clinical study
15. Volunteer who used antibiotics or antifungal medication (topical to scalp and systemic) in the past 4 weeks
16. Volunteer who used probiotics supplements in the past 4 weeks. (dietary probiotics such as yogurt, kefir, and kimchi are acceptable)
17. Volunteer who follows a non-conventional diet (e.g. vegan, ketogenic, strict intermittent fasting diets)
18. Volunteer who used anti-dandruff shampoo in the past 4 weeks (For example, commonly used brands for anti-dandruffs could be : Head \& Shoulders, Sebamed, Clear, Dove, Pantene, L'OREAL, Vichy Dercos)