Bacterial Vaginosis (BV) is considered the most prevalent form of vaginal infection in women of reproductive age, affecting from one-quarter to one-third of women. Women suffering from BV report diminished quality of life from symptoms that typically include abnormal, often malodorous vaginal discharge. Additionally, BV increases the risk of upper genital tract infection, sexually transmitted infections (STI), such as HIV and Herpes, complications of pregnancy, pre-term birth, and lower success in fertility treatments. Treatment with antibiotics (either systemic or vaginal) remains disappointing; with a 30% relapse rate of symptomatic BV within three months of initial treatment, and up to 50-70% within a year. Moreover, chronic or frequent antibiotic treatment predisposes treated patients to the risk of vaginal candidiasis. Many women therefore suffer from intractable, persistent or recurrent BV with very limited therapeutic options.

The collaboration between the Elinav group and Hadassah hospital generated a protocol to transplant microbiome from healthy donors into afflicted women (Fig. 1). Donors were screened for a variety of factors including general health and lacking symptoms of BV for at least 5 years. Vaginal microbiomes were then collected and transferred to women diagnosed with BV. In controlled study women who underwent transplantation were tracked for one year to determine the efficacy of a single treatment and to determine whether additional vaginal microbial transplants were needed. Lastly, the vaginal microbiomes of the recipients were 16s rDNA sequenced to determine compositions of bacterial populations.