A common bacteria that boosts digestive health can slow - and even reverse - build-up of a protein associated with Parkinson's, new research suggests.
Building on previous research linking brain function to gut bacteria, this study in a Parkinson's model of roundworms, identified a probiotic - or so-called good bacteria - which prevents the formation of toxic clumps that starve the brain of dopamine, a key chemical that coordinates movement. These new findings could pave the way for future studies that gauge how supplements such as probiotics impact the condition.
In the brains of people with Parkinson's, alpha-synuclein protein misfolds and builds up, forming toxic clumps. These clumps are associated with the death of nerve cells responsible for producing dopamine. The loss of these cells causes the motor symptoms associated with Parkinson's, including freezing, tremors and slowness of movement.
The researchers used roundworms altered to produce the human version of alpha-synuclein that forms clumps. They fed these worms with different types of over-the-counter probiotics to see if bacteria in them could affect the formation of toxic clumps.
The scientists found that a probiotic called Bacillus subtilis had a remarkable protective effect against the build-up of this protein and also cleared some of the already formed protein clumps. This improved the movement symptoms in the roundworms. This protection is seen in young and aging animals and is partly mediated by DAF-16.
Multiple B. subtilis strains trigger the protective effect via both spores and vegetative cells, partly due to a biofilm formation in the gut of the worms and the release of bacterial metabolites. The authors identify several host metabolic pathways differentially regulated in response to probiotic exposure, including sphingolipid metabolism. The authors further demonstrate functional roles of the sphingolipid metabolism genes lagr-1, asm-3, and sptl-3 in the anti-aggregation effect.
The study published in the journal Cell Reports is the latest in a number of recent studies which have found a link between brain function and the thousands of different kinds of bacteria living in the digestive system, known as the gut microbiome. Other studies into mice have found that the gut microbiome has an impact on the motor symptoms.
Lead researcher said: "The results provide an opportunity to investigate how changing the bacteria that make up our gut microbiome affects Parkinson's. The next steps are to confirm these results in mice, followed by fast-tracked clinical trials since the probiotic we tested is already commercially available."
Protein aggregation in Parkinson's slowed by gut bacteria
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