Bacterial vaginosis is a problem for many women, with estimates that up to a third of women of reproductive age get it at some point in life. Bacterial vaginosis is a condition where the microbes in the vagina are imbalanced or out-of-whack, especially with diminishing numbers and types of Lactobacillus species. Lactobacillus species are typically the dominant bacteria in healthy vaginal microbiomes.
Unfortunately, some women have recurring bacterial vaginosis (BV), many who wind up taking course after course of antibiotics to try to deal with it. Symptoms can include thin gray, white, or green vaginal discharge, vaginal itching, burning during urinbation, and a smelly fishy vaginal odor. Which is why a small study done in Israel finding success with vaginal microbial transplantation (VMT) from healthy donors to women with BV is very exciting.
Researchers transplanted vaginal fluid (with all its microbes) from 3 healthy women (and thus a healthy vaginal microbial community) into 5 women with severe BV that did not respond well to antibiotics. Afterwards four of the recipients had long-lasting (up to 21 months) vaginal microbial changes and complete remission of BV (2 after the first transplant, 2 after 3 transplants) - becoming more like the donors' vaginal microbiome, and also rich in Lactobacillus. The 5th person had partial improvement of BV, but there were complications - she took a course of antibiotics for a throat infection, her BV symptoms returned, and then she received another vaginal microbiome transplant, after which her vaginal microbes were a mix of her original and the donors.
Of course larger studies are now needed, especially because there can be risks when receiving another person's microbes (e.g. accidental transfer of viruses). But I also want to point out that some of these Lactobacillus species (especially Lactobacillus crispatus) are easily available without a prescription, and women have been self-experimenting with them, many with good success.