US doctors get the go ahead to test ‘vaginal bacteria transplants’

US doctors have been given the go ahead to test ‘vaginal bacteria transplants’ in women with bacterial vaginosis (BV).

Researchers at John Hopkins University in Baltimore plan to take vaginal fluid from healthy donors. 

The donors’ ‘good bacteria’ will be put into a tampon-like device and tested in a trial of around 40 BV sufferers, with some having the vaginal microbiota transplant (VMT) and others a placebo. 

The US Food and Drug Administration approved the trial after the doctors took vaginal fluid from 20 volunteers in a pilot study.

The medics claim ‘unfit’ donors could be easily ‘screened out’, with further tests then determining their ‘bacterial quality’. 

The unusual approach, inspired by faecal transplants, could provide a ‘fully curative or restorative’ BV therapy. The condition is currently treated via antibiotics but often recurs within three months.

It is unclear when the trial will begin. The doctors said they would ‘start right away’ if they had the necessary funding. 

US doctors have been given the go ahead to test 'vaginal bacteria transplants' in women with bacterial vaginosis. This occurs when there is a shift in the balance of vaginal bacteria (stock)

US doctors have been given the go ahead to test ‘vaginal bacteria transplants’ in women with bacterial vaginosis. This occurs when there is a shift in the balance of vaginal bacteria (stock)

BV occurs when there is a shift to the natural balance of bacteria in the vagina. This can come about due to diet, medication, the menstrual cycle or douching.

Although symptom-less half the time, BV can trigger unusual discharge with a strong fishy smell. 

Prolonged BV has even been linked to cervical cancer, as well as premature birth and miscarriage in pregnant women.

The doctors were inspired by the success of faecal transplants, where healthy stools are transplanted into the gastrointestinal tracts of C.difficile sufferers.

Although it may sound nauseating, the procedure has been shown to be successful in up to 92 per cent of recurrent infections that do not respond to antibiotics. 

‘We anticipate the trajectory of VMT will likely follow that of fecal transplantation, with efforts to cultivate uniform, standardised transplants that have similar therapeutic efficacy to donor material,’ study author Dr Laura Ensign said.

While a diverse range of bacteria is critical for good gut health, Lactobacillus should dominate the vagina to prevent BV, the doctors wrote in the journal Frontiers in Cellular and Infection Microbiology.  

Despite BV’s serious risks, treatment is limited to antibiotic tablets, creams or gels. 

‘We have very few treatment options available for BV, none of them fully curative or restorative,’ study author Dr Ethel Weld said.

This treatment need prompted the doctors to wonder whether VMT could be effective.  

‘There is significant epidemiological evidence that vaginal microbiota transfer already occurs, for example between women who have sex with women,’ Dr Weld said.  

The researchers tested their theory in 20 healthy women aged between 23 and 35.


Bacterial vaginosis (BV) is a common cause of unusual vaginal discharge.

It affects around one in three women at some point in their lives. 

Although it is not an STI, it does increase a woman’s risk of catching a sexually-transmitted infection.

BV is caused by a change to the delicate bacterial balance in a woman’s vagina. 

The most common symptom is a fishy-smelling discharge, particularly after sex.

There may also be a change to the discharge’s colour or texture, such as it becoming grey or watery.

But half of women with BV experience no symptoms.

If a woman suspects she has BV, she should go to her GP or sexual-health clinic to confirm it is not an STI. 

Once diagnosed – via a cotton bud ‘smear’ – BV is usually treated via prescribed antibiotic tablets, or gels or creams.

BV often returns within three months.

Those who get it more than twice in six months will need treatment for up to half-a-year. 

BV can be prevented by using just water to wash the genital area and opting for showers over baths.

Perfumed soaps, vaginal deodorants, douches, strong detergents and even smoking raise a woman’s risk of the condition. 

BV is more common in those who are sexually active, have recently changed their partner or have ‘the coil’. 

If ‘caught’ during pregnancy, BV can lead to a premature birth or miscarriage.

Worried pregnant women should speak to their GP or midwife.

Source: NHS Choices 

The women completed a medical questionnaire, and had their blood, urine and vaginal fluid examined. 

The doctors believe cheap tests reliably rule out women with any sexually transmitted infections (STIs) or other safety concerns.   

Once deemed suitable, the women ‘self collected’ their vaginal fluid via a flexible plastic disc, similar to a menstrual cup, the BBC reported. 

‘It’s quick and easy, and one sample collected like that would be enough material to make one dose for transfer,’ Dr Ensign said. 

A recipient would also ‘self administer’ the transplant, with the donor bacteria being put into a tampon-like device.

In the future, more expensive tests could screen the most promising donors, who would be ‘graded’ according to their Lactobacillus levels.

It is unclear what makes the ‘ideal’ donor. The pilot study found, however, the women whose vaginas were dominated by the Lactobacillus species L. crispatus tended to have more lactic acid, which is protective.

They also had a lower pH and greater ‘HIV barrier function’, the study found. An alkaline pH can allow bacteria, including those behind BV, to thrive.

‘Once a safe donor has been identified using this protocol, she could donate on multiple appropriately screened occasions,’ Dr Ensign said.

‘The idea of a “super-donor” with no identified past or current infections and with favorable Lactobacillus-dominated microbiota is one that should be explored.’ 

The study also suggested these super donors may be hard to come by.  

‘Based on our exclusion criteria, seven out of 20 (35 per cent) of these participants might be eligible VMT donors,’ Dr Ensign said. 

‘But the actual success rate for participation as a VMT donor in a clinical trial will likely be much lower still.’ 

The women were recruited from past studies carried out by the same researchers. 

They were mostly white or east Asian. In the US, these ethnic groups are the least likely to have BV, the doctors claim. They hope to recruit a more diverse pool of women in their upcoming study. 

However, persuading women to take part may be challenging, with participants being asked to go 30 days or more without sex. 

‘Out of an abundance of caution, we propose donors abstain from vaginal intercourse for the duration of longitudinal sample collection,’ Dr Ensign said.   

The researchers added, however, some of the donors from their pilot study have expressed interest in the upcoming trial.

‘If we can get funding, we could start right away,’ Dr Ensign said.

‘We’d plan to give transplants to 40 recipients to begin with. Some would receive the real thing and others a placebo.’

All the participants would also be treated with antibiotics, she added. 


Faecal microbiota transplantation (FMT) is the transfer of stool from a healthy donor into the gastrointestinal tract of a patient.


It is most commonly used to treat recurring C. difficile infection – spread by bacterial spores found within faeces. It is 90 per cent effective.

It can also be used to treat gastrointestinal conditions such as colitis, irritable bowel syndrome and constipation – but success rates are much lower. 

Recent studies have delved into the benefits of treating conditions linked to a poor balance of ‘good’ and ‘bad’ bacteria in the gut, such as autism. 

Faecal microbiota transplantation (FMT) is the transfer of stool from a healthy donor into the gastrointestinal tract of a patient

Faecal microbiota transplantation (FMT) is the transfer of stool from a healthy donor into the gastrointestinal tract of a patient

FMT can replenish bacterial balance as it acts like a probiotic, with samples of faeces often containing up to 1,000 different species of bacteria.  


The transplant is done via tubes – inserted into the nostril, down the throat and into the stomach – or directly into the colon.

However, the faecal sample can also be transplanted through enemas or pills containing freeze-dried material.


There have been reports of patients showing unexpected weight gain after treatment, bouts of vomiting and even abdominal pain.

However, the long-term safety and effectiveness of FMT is relatively unknown, and researchers have called for more studies to determine the risks. 


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