SCOTTSDALE, AZ USA (UroToday.com) - Dr. Rebecca Brotman gave a very informative lecture on the vaginal microbiome and its implications to clinical practice. She presented some of her ongoing research and began by noting that adult humans harbor approximately 10-times more microbial cells than human cells. We are at the beginning of understanding how changes in microbiome can affect our health. Cultivation in vitro cannot be applied to many of the most densely populated microbial communities as > 90% of species have not been successfully grown in culture. There are large-scale endeavors currently underway, including the NIH Human Microbiome Project and the EU MetaHIT Consortium.
Vaginal bacteria play a key role in preventing colonization by pathogenic organisms. One example is the Lactobacillus species which produces antimicrobial metabolites and copious amounts of lactic acid resulting in a protective, low vaginal pH (< 4.5). This can lower a woman’s risk to urinary tract infections (UTIs), sexually transmitted infections (Trichomonas vaginalis, HPV, HIV), bacterial vaginosis (BV), and genitourinary syndrome of menopause (GSM-new term for atrophic vaginitis) While it also assists with microbiome acquisition of the baby during vaginal delivery, it also contributes to vaginal odor, well-being, sexual health. So by increasing our understanding of vaginal microbiota we can move the needle forward in women’s health.
Dr. Brotman noted that we are not ready for interventional trials as we do not know what bacteria are there and if and how they fluctuate over time. We do not know what factors affect vaginal microbiota and how these microbiota are associated with diseases.
She presented interesting data on the vaginal microbiome of reproductive-age women in the U.S. (n=394) and noted that vaginal microbiota varies by ethnic background. Forty percent of African American women she studies lacked lactobacillus. She presented plots depicting the stability of vaginal community states in 33 women over a 16-week period. She noted the epidemiologic factors associated with fluctuations in the vaginal microbiota. Sexual activity and menstruation are always the two variables most highly associated with vaginal microbiota, but other variables of interest include vaginal douching, feminine hygiene practices, hormonal contraception, diet, lubricant use, smoking, age, and ethnicity.
Vaginal microbiota are associated with HPV clearance. Urinary tract infections are common in women across the lifespan and the problem of antibiotic resistance among uropathogens necessitates the development of alternative non-antibiotic methods for the prevention of recurrent UTIs. She noted the non-antibiotic treatments for recurrent UTIs:
- Probiotics
- Postmenopausal women: oral L rhamnosus GR-1 and L reuteri RC-14 (109 colony-forming units) vs trimethoprim-sulfamethoxazole 480mg
- 12-month prophylaxis, n=252 women
- Probiotics were slightly inferior in uncomplicated UTI but did not increase antibiotic resistance
- In women with complicated UTIs, TMP/SMX less effective possibly because baseline resistance rates in this patient group were higher.
- Premenopausal:
- Vaginal Lactobacillus suppository (Lactin-V, L. crispatus) after antimicrobial treatment reduced recurrent UTI
- Most women in Lactin-V group had “low levels” of L. crispatus detected
- Larger studies needed, n=100 in this study
- Postmenopausal women: oral L rhamnosus GR-1 and L reuteri RC-14 (109 colony-forming units) vs trimethoprim-sulfamethoxazole 480mg
- Cranberry products
- Cochrane systematic review
- Preparation? Dosing? Frequency?
- Estrogens in postmenopausal women
- Topical estrogens are effective at reducing UTIs
- Oral estrogen replacements have NOT been found to be effective at reducing recurrent UTIs
- Estrogen vaginal ring delayed recurrences
Presented by Rebecca M. Brotman, PhD, MPH at the Society of Urodynamics, Female Pelvic Medicine and Urogenital Reconstruction (SUFU) Winter Meeting - February 24 - 28, 2015 - JW Marriott Camelback Inn Resort & Spa - Scottsdale, AZ USA
Institute for Genome Sciences, Department of Epidemiology and Public Health, University of Maryland School of Medicine
Reported by Diane K. Newman, DNP, FAAN, BCB-PMD, medical writer for UroToday.com.