NIH Clinical Center logo     America's Clinical Research Hospital File folder iconExplore the NIH
Clinical Center
Search the Studies - NIH Clinical Research Studies

Protocol Details

Microbiomic and Immunologic Profiling of Women with Antibiotic induced Vaginal Candidiasis

This study is currently recruiting participants.

Summary | Eligibility | Citations | Contacts




Sponsoring Institute

National Institute of Allergy and Infectious Diseases (NIAID)

Recruitment Detail

Type: Participants currently recruited/enrolled
Gender: Female
Min Age: 18
Max Age: 40

Referral Letter Required


Population Exclusion(s)


Special Instructions

Currently Not Provided


Vulvovaginal Candidiasis;

Recruitment Keyword(s)



Antibiotic-Induced VVC;
Vaginal Candidiasis

Investigational Drug(s)


Investigational Device(s)




Supporting Site

National Institute of Allergy and Infectious Diseases


- Vaginal yeast infections are caused by a fungus called Candida. Candida can live harmlessly in the vagina, but most women will have symptoms from a vaginal yeast infection at some point during their life. Antibiotics increase the risk for yeast infections, but it is unclear why. They may disrupt the balance of healthy bacteria in the vagina. This could make it harder for the body to fight off yeast infections. Researchers will give healthy women a common antibiotic or a placebo. They will study how the antibiotic affects bacteria and yeast in the vagina and other parts of the body. This will let researchers study the normal changes of healthy bacteria and yeast over time.


- To see how the study drug changes healthy bacteria in the vagina, and how these changes may increase the risk for yeast infections.


- Healthy women ages 18 to 40 who are not allergic to penicillin.


- Participants will be screened with medical history, physical exam (including vaginal exam), blood tests and tests for sexually transmitted diseases.

- Participants must take birth control pills for at least 3 months before, and during the study.

- Participants will take the study antibiotic or placebo for 10 days.

- Participants will have 7 study visits over 3 months. Visits will be timed around participants menstrual cycles.

- At the visits, participants will answer questions about their health and undergo tests. These may include swabs of the vagina, mouth and skin as well as blood tests. Vaginal fluid, saliva and urine will also be collected.

- Between visits, participants will collect stool and vaginal samples at home and bring them to the next clinic visit.

--Back to Top--



Females 18-40 years of age must meet the following criteria to be eligible for participation in this study:

-Willing and able to comply with the procedures of the protocol

-Able to provide informed consent

-Able to swallow capsules

-Have a history of regular (approximately 21-35 day) menstrual cycles prior to initiation of hormonal contraception

-On oral contraceptives for at least 3 months prior to sampling (see Participation of Women below)

Participation of Women:


Because menstruation is known to affect the vaginal microbiome and because oral contraceptives produce predictable menstrual cycles, subjects must be on oral contraceptives in order to be eligible for the study. Additionally, since amoxicillin may theoretically reduce the efficacy of oral contraceptives, subjects must agree to use an additional form of contraception (barrier method, abstinence) while receiving the study drug.


A subject will not be eligible if she has any of the following:



-Known allergy to beta-lactam antibiotics (e.g., penicillin)

-Body mass index (BMI) greater than or equal to 35 or less than or equal to 18 at screening visit

-Vital signs outside of acceptable range at screening visit (i.e. blood pressure > 160/100, oral temperature > 100 degrees F, pulse > 100)

-Primary or acquired immunodeficiency, including Human Immunodeficiency Virus (HIV) (diagnosed via an FDA-approved test)

-Hepatitis C seropositivity or positive Hepatitis B surface antigen

-Chronic, clinically significant (requiring on-going medical management or medication) pulmonary, cardiovascular, dermatologic, endocrine, gastrointestinal, hepatic or renal functional abnormality, as determined by medical history and physical examination and/or laboratory testing (Complete blood count [CBC] with differential, Acute Care Panel, Hepatic Panel)

-Active malignancy or history of malignancy for which there is not reasonable assurance of sustained cure

-Major surgery of the gastrointestinal tract, including any major bowel resection at any time, with the exception of cholecystectomy and appendectomy, in the past five years

-Genitourinary/Gynecologic conditions, including:

a. Urinary incontinence necessitating use of incontinence protection garments

b. Treatment for or suspicion of ever having had toxic shock syndrome

c. History of hysterectomy

d.History of vulvar, vaginal or cervical dysplasia within the previous 5 years

e. History of condyloma or human papillomavirus (HPV) diagnosed within the previous 2 years

f. History of candidiasis, urinary tract infection, or STD (specifically chlamydia, gonorrhea, syphilis, genital herpes, trichomoniasis) diagnosed within the previous 6 months

g. Evidence (by history or physical exam) of vulvar or vaginal irritation at screening

-Chronic smokers and subjects who use smokeless tobacco products (due to known effects of tobacco on the oral microbiome)

-Exposures to the following agents (which could affect the microbiome) within 6 months prior to sampling:

a. Systemic antibiotics, antifungals, antivirals or antiparasitics (intravenous (IV), intramuscular (IM) or oral)

b. Vulvar/vaginal antifungal or hormonal medications

c. Intrauterine device (IUD) or hormonal vaginal ring (e.g. Nuvaring) due to unknown duration of local hormone effects

d. Oral, IV, IM, nasal or inhaled corticosteroids, or use of high-dose topical steroids in areas to be sampled

e. Immunosuppressive or immune-modulating agents, such as cytokines, methotrexate or other chemotherapies

f. Large doses of commercial probiotics (greater than or equal to 10(8) cfu/day) (ordinary fermented beverages/milks/yogurts/foods are acceptable)

g. Intranasal influenza vaccination due to effects on mucosal immunity

-Any medical, psychiatric, social condition, occupational reason or other responsibility that, in the judgment of the investigator, is a contraindication to protocol participation or impairs a volunteer s ability to give informed consent

-Creatinine clearance < 50 mL / min

--Back to Top--


Sobel JD, Faro S, Force RW, Foxman B, Ledger WJ, Nyirjesy PR, Reed BD, Summers PR. Vulvovaginal candidiasis: epidemiologic, diagnostic, and therapeutic considerations. Am J Obstet Gynecol. 1998 Feb;178(2):203-11.

Ravel J, Gajer P, Abdo Z, Schneider GM, Koenig SS, McCulle SL, Karlebach S, Gorle R, Russell J, Tacket CO, Brotman RM, Davis CC, Ault K, Peralta L, Forney LJ. Vaginal microbiome of reproductive-age women. Proc Natl Acad Sci U S A. 2011 Mar 15;108 Suppl 1:4680-7. doi: 10.1073/pnas.1002611107. Epub 2010 Jun 3.

Pirotta MV, Garland SM. Genital Candida species detected in samples from women in Melbourne, Australia, before and after treatment with antibiotics. J Clin Microbiol. 2006 Sep;44(9):3213-7.

--Back to Top--


Principal Investigator

Referral Contact

For more information:

Michail S. Lionakis, M.D.
National Institute of Allergy and Infectious Diseases (NIAID)
BG 10 RM 11C102
(301) 443-5089

Elise M. Ferre, P.A.-C
National Institute of Allergy and Infectious Diseases (NIAID)
BG 10 RM 11C110
(301) 496-8985

Patient Recruitment and Public Liaison Office
Building 61
10 Cloister Court
Bethesda, Maryland 20892-4754
Toll Free: 1-800-411-1222
TTY: 301-594-9774 (local),1-866-411-1010 (toll free)
Fax: 301-480-9793

Clinical Trials Number:


--Back to Top--


Contact the Patient Recruitment and Public Liaison Office for:

  • Details on how to participate in a study
  • Details on how to refer a patient to a study

NIH Clinical Studies Information Request

Contact the Office of Communications for:

  • General information about the NIH Clinical Center

Contact the Department Clinical Research Informatics, (DCRI) for:

  • Technical questions about Adobe Acrobat and the PDF format
  • Technical questions about this web server