Inclusion Criteria:  AA patients with:  Acute disease that appeared in the last 3 months. Recurrence of AA in the last 3 months, in a patient who had remission for at least one year. At least one patch of hair loss on the scalp and / or the beard, or with a widespread disease such as total loss of the hair over the entire scalp (alopecia totalis). In case of a single alopetic patch, the patch must be equal or bigger than 2 cm in diameter. All patients will be diagnosed by two separate dermatologist, or one dermatologist with the support of classical finding on skin biopsy.  Exclusion Criteria:  Patients who were treated with systemic corticosteroids / corticosteroids injection one year prior the study. Patients who were treated with topical corticosteroids two weeks prior the study. Patients who were treated with immunosuppressing medications or biological treatments one year prior the study. Patients who were treated with systemic antibiotics of any kind 3 months prior the study. Patient who were treated with topical antibiotics one months prior the study. Patients who were treated with probiotics one months prior the study. Patients with alopecia universalis (total loss of all body, scalp and facial hair). Patients with bowel disease or an active infection including clostridium difficile. Pregnant and breastfeeding women. Childrenbelow the age of 18. Malignant disease in the past 5 years. Patient with any infectious disease that require antibiotics during the study period.  In any case a patient would like to withdraw from the study, for any reason, all samples will be destroyed immediately, and the patient will stop his participant in the study.