Comparing Sarecycline and Doxycycline Effects on the Skin and Gut Bacteria in Acne.

Inclusion Criteria:

1\) Diagnosis of acne vulgaris with:

* At least 10 inflammatory lesions (papules, pustules, and nodules) up to 100 noninflammatory lesions (open and closed comedones)
* No more than 2 nodules on the face

Exclusion Criteria:

1. Dermatological condition of face or facial hair that could interfere with clinical evaluations
2. Subjects who have used the following medications (topical refers only to the facial area) will not be eligible:

2a) Within 2 week prior to randomization:

* Topical acne medications such as retinoids, antibiotics, hormonal modulators
* Topical benzoyl peroxide
* Topical anti-inflammatories and corticosteroids

  2b) Within 4 weeks prior to randomization:
* Systemic antibiotics
* Systemic acne treatments
* Oral probiotic supplement
* Systemic corticosteroids

  2c) Within 12 weeks prior to randomization:
* Systemic retinoids

  3\) Individuals who have changed any of their hormonal based contraception or therapies within 3 months prior to joining the study.

  4\) Individuals who are pregnant or breastfeeding.

  5\) Individuals on oral contraceptive pills or progesterone or estrogen containing therapies unless they have been on a stable dose for 2 months.

  6\) Individuals on finasteride or dutasteride

  7\) Current tobacco smoker or a tobacco smoking history that is greater than 5 pack-years.