• Garlic could also cause biofilms to form, which are a collection of microorganisms such as plaque on teeth.
• The bacteria themselves aren't harmful, but they can produce one of the most poisonous toxins
A gynaecologist has urged women to not put garlic in their vagina to treat yeast infections.
Dr Jen Gunter, based in California, went on a Twitter rant about the old wives' tale, which recommends putting a clove inside the vagina for up to three days.
There are no studies to support the claim garlic has antifungal properties – apart from in a petri dish – and it could be a serious risk for further infections, Dr Gunter said.
The vagina is the ‘perfect’ environment for the botulism bacteria to grow, which can be life-threatening and lead to paralysis.
It's not the first time doctors have busted similar myths, including one claiming parsley in the vagina can induce periods.
Dr Gunter, a health columnist and author of a book called The Vagina Bible, wrote on Twitter: 'My advice, do not take medical advice from anyone recommending vaginal garlic for yeast or anything else.'
The now viral twitter thread started off by explaining that garlic contains allicin, which in the lab has shown to have antifungal properties.
'This is in a lab, not even in mice. Just a dish of cells. Your vagina is not a dish of cells,' Dr Gunter said.
She delved into the serious risks of garlic, firstly because it could have bacteria from the soil on it.
'Bacteria from the soil can be pathogenic - bad for the body. That's why we clean wounds,' Dr Gunter wrote.
'If you actually happen to have an inflamed yeasty vagina that soil bacteria would be more likely to infect.'
Garlic could also cause biofilms to form, which are a collection of microorganisms such as plaque on teeth.
'You do not want them to form especially when you have yeast,' Dr Gunter said.
But the most concerning risk Dr Gunter warns of is clostridium bacteria, found in soil, which may be on the garlic.
The bacteria themselves aren't harmful, but they can produce one of the most poisonous toxins when deprived of oxygen, such as in closed cans or bottles.
Dr Gunter said: 'You know why you refrigerate home made garlic vinaigrette? So any clostridium bacteria laying around on the garlic doesn’t produce botulinum toxin. Right. The vagina is an anaerobic environment, so perfect for clostridium.'
Botulism, a condition caused by clostridium botulinum bacteria, can be caused when someone eats food containing the toxins because it hasn't been properly canned, preserved or cooked.
It needs hospital treatment as the toxins attack the nervous system and cause paralysis. This is fatal in five to ten per cent of cases, according to NHS.
Part of the problem, Dr Gunter said, is women self diagnosing and treating problems that may not be there, further throwing off the balance of the vagina.
She said: 'As 50 to 70 per cent of women who self treat for vaginal yeast never actually had a yeast infection you can't say much, except half of them never had yeast to begin with so the irritation they had may have been a temporary thing and resolving wasn't garlic relate [sic].'
Dr Gunter claimed many people who use the 'remedy' - who may just experience a strong placebo effect - are doing it wrong.
Without crushing the garlic, the possible anti fungal allicin is not released, Dr Gunter said.
One tweeter, Raquelle Jason, hit back at the expert in the belief that big pharmaceutical companies are scaring people away from natural remedies.
She said: 'You are wrong. Garlic has helped me and everyone else I've told about it when prescription meds were not possible.'
She posted the recipe which she uses herself, requiring garlic to be inserted in a gauze made of dental floss for 12 hours for three days.
A vaginal yeast infection causes irritation, discharge and intense itchiness. The most common are bacterial vaginosis or thrush.
It affects three in four women at some point in their lives, according to the Mayo Clinic.
The vagina is designed to keep itself clean with the help of natural secretions and there are lots of bacteria inside to protect it.
The bacteria help keep the pH balance, produce bacteriocins (naturally occurring antibiotics) and produce a substance that stops invading bacteria sticking to the vagina walls and causing damage to tissue, according to the NHS.
If the balance of bacteria is disturbed, this can lead to infection.