Scientists identify gut bacteria linked to neurodegenerative conditions
A study on worms points to gut bacteria that can kick-start Alzheimer’s and Parkinson’s, and ones that can counteract these conditions
Researchers have identified gut bacteria species that appear to play a role in the development of neurodegenerative diseases such as Alzheimer’s, Parkinson’s and motor neurone disease.
Previous research has found a relationship between these conditions and changes in the gut microbiome – the colonies of microbes that call our digestive system a home. Unfortunately, an individual’s microbiome is made up of tens of thousands of species, so it has been tricky to untangle which microbes are involved in this effect. Now, researchers at the University of Florida have not only identified the harmful bacteria species, but have also shown that certain other species can produce compounds that counteract their impact.
“Looking at the microbiome is a relatively new approach to investigating what causes neurodegenerative diseases. In this study, we were able to show that specific species of bacteria play a role in the development of these conditions,” said Dr Daniel Czyz, assistant professor at the University of Florida.
“We also showed that some other bacteria produce compounds that counteract these ‘bad’ bacteria. Recent studies have shown that patients with Parkinson’s and Alzheimer’s disease are deficient in these ‘good’ bacteria, so our findings may help explain that connection and open up an area of future study,” he said.
Neurodegenerative disorders result from proteins building up in tissue in the body. These accumulations of proteins can interfere with cell function. The team studied the link between gut bacteria and neurodegenerative disease in a worm called Caenorhabditis elegans. When the worms were infected with the harmful bacteria, proteins began to aggregate in their tissues.
“We have a way of marking the [protein] aggregates so they glow green under the microscope,” said Czyz. “We saw that worms colonised by certain bacteria species were lit up with aggregates that were toxic to tissues, while those colonised by the control bacteria were not.”
The worms also lost mobility. “A healthy worm moves around by rolling and thrashing. When you pick up a healthy worm, it will roll off the pick – a simple device that we use to handle these tiny animals,” said lead author Alyssa Walker. “But worms with the bad bacteria couldn’t do that because of the appearance of toxic protein aggregates.”
The team hopes to carry out further experiments in higher organisms and then, eventually, in humans.