Taking antibiotics long-term may reduce Alzheimer's symptoms and the plaques thought to underlie the disease, a new study in mice suggests.
But it only works in males.
In recent years, scientists have amassed a growing body of research suggesting a link between gut bacteria and Alzheimer's disease.
Antibiotics alter the gut microbiome - sometimes for the worse - so the team at the University of Chicago experimented with treating bred to have Alzheimer's with the disease.
They found that treating male mice with a cocktail of several antibiotics slowed the build up of Alzheimer's-associated amyloid beta plaques in their brains, but females treated the same way reaped no benefits.
A long-term cocktail of antibiotics did nothing to treat Alzheimer's disease in female mice (left) but it altered males' gut bacteria to shrink amyloid plaques related to the disease (right)
Alzheimer's is a fearful disease for many reasons, not least of all because it remains mysterious, incurably, and only barely treatable.
For decades, the amyloid beta theory has prevailed as best explanation science had to offer for the debilitating and ultimately deadly memory loss of Alzheimer's.
But autopsies have also shown similar tangles and plaques in people who had had perfectly good memories before their deaths.
DNA partially determines Alzheimer's risks - most notably, the APOE-e4 gene - but what separates those whose beta amyloid plaques cause Alzheimer's and whose don't has been something of a scientific black box.
Now, researchers think that the key to the brain disease may lie bacteria.
Both P gingivalis - the bacteria involved in gum disease, an Alzheimer's risk factor - and certain gut bacteria have been linked to
