Chiropractor Stefanie Webb firmly believes in prevention
being better than a cure. So while she was on a course
of antibiotics for a nasty stomach bug, Stefanie treated
herself to helpings of live yogurt. It's universally believed
that Lactobacillus acidophilus � the good micro-organisms
in this food � will fill up the spaces in the stomach
and vagina denuded by the drugs before less well-intentioned
bacteria gain a foothold. In fact, a sizable industry
has developed which produces Lactobacillus yogurts
and topical creams to forestall this problem. However,
a study in the August 27 issue of the BMJ found
that these products are completely useless at controlling
vaginal yeast infections in women who have taken antibiotics.
A clue as to why this preventative
measure is futile lies in the term 'yeast infection.'
This is because vulvovaginitis is not generally caused
by bacteria, but by the yeast Candida albicans.
The bacteria Lactobacillus and the yeast Candida
don't necessarily share the same niche in the microecology
of the vagina. So trying to make sure there's no room
for Candida by filling up the spaces with Lactobacillus
doesn't work.
The Australian authors of the new
study, led by Dr Suzanne Garland of the Royal Women's
Hospital in Carlton, had argued that applying friendly
bacteria to the vagina, or eating them in the hope that
they will end up there, is a classic example of a treatment
that is widely used despite having no plausible biological
mechanism of action and no recorded evidence of effectiveness.
They decided to put Lactobacillus
to the test themselves, recruiting 235 non-pregnant
women aged 18-50 years who required a short course of
oral antibiotics for a non-gynecological infection.
The women took probiotic or placebo preparations either
orally or vaginally. They began at the time of their
first antibiotic, and discontinued four days after their
last.
Overall, 23% of the subjects developed
vulvovaginitis. Women taking probiotics were at least
as likely as those on placebo to be smitten by a Candida
infection, possibly even more so in the case of topical
application. There was simply no benefit whatsoever.
In fact, the trial was stopped early as it seemed pointless
to continue.
"Further research on this
subject is unlikely to be fruitful," said the authors.
It's possible to read a great many research papers without
ever coming across this refreshingly honest statement.
They concluded: "Our results should prompt health professionals
to inform women that Lactobacillus is unlikely
to prevent post-antibiotic vulvovaginitis and that they
should consider using proved antifungal treatment if
symptoms develop."
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