You probably already know that what’s good for the heart tends to be good for the brain. Healthy blood pressure and well-maintained arteries could help to reduce our risk of conditions like dementia.
But some researchers think another system – our gut – could play a role here, too, because the “brain and the gut microbiome are connected through the gut-brain axis”.
This theory suggests that bacteria in our digestive tract might just play a role in how our brain ages.
And recently, a study published in the Journal of Alzheimer’s Disease found that, among a small group of participants, taking probiotics (bacteria designed to improve your gut health) seemed to lower dementia risk.
What might probiotics have to do with dementia?
In this study, researchers put 87 members of the Gwangju Alzheimer’s Disease and Related Dementias cohort through a randomised, double-blind trial.
40 took a multi-strain probiotic – one that contained a variety of bacteria, including Bifidobacterium animalis, Limosilactobacillus fermentum, and Levilactobacillus brevi– for 24 weeks, while 47 stayed on a placebo.
After the trial, the individuals who’d taken the probiotic had lower plasma levels of pTau181 and also scored better than the placebo group on a Clinical Dementia Rating system.
pTau181 is a blood marker that indicates higher levels of modified tau proteins. It’s long been associated with dementia risk, because misshapen tau that turns into “tangles” in the brain can be viewed as a precursor to the condition.
Additionally, an inflammation marker called IL-1β was lowered among those who took multi-strain probiotics.
Scientists have previously looked into the possible role of brain inflammation (“neuorinflammation”) in the development of dementia.
The study authors wrote: “This finding may suggest a selective anti-inflammatory effect of the multi-strain probiotic on specific cytokine pathways”.
Does this mean taking probiotics will definitely prevent dementia?
This study doesn’t show that. It just showed that a biomarker suggestive of elevated tau tangles seemed to get lower, and that there was an apparent link between probiotic supplementation and better cognitive scores.
Dementia likely has many causes, and in a small amount of cases, tau tangles have been noted in the brains of people who didn’t have dementia.
But the researchers concluded that this combination was promising.
“These findings suggest the potential role of microbiota-targeted interventions as a non-pharmacological adjunct for early cognitive impairment, although further studies are required to confirm underlying mechanisms,” the paper reads.
