Neurodegenerative diseases such as Alzheimer̵
Recent studies show that people with these conditions show changes in the bacterial composition of their digestive tract. However, given the wide variety of microbes found in the human body, identifying which bacteria may be associated with neurodegeneration is like finding a needle in a haystack.
Searching for this proverbial needle, researchers at the University of Florida are looking for an unexpected place: the digestive tract of a tiny, translucent worm called Caenorhabditis elegans.
A new study published in PLOS pathogens establishes for the first time a connection between specific types of bacteria and physical manifestations of neurodegenerative diseases. The lead author of the study is Alice Walker, a PhD student in microbiology and cell sciences at UF / IFAS College of Agricultural and Life Sciences.
“Examining the microbiome is a relatively new approach to studying the causes of neurodegenerative diseases. In this study, we were able to show that specific types of bacteria play a role in the development of these conditions,” said Daniel Cheese, Walker’s dissertation advisor.
Czyz is a senior research author and assistant in the UF / IFAS Department of Microbiology and Cell Sciences.
We have also shown 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 to help explain this connection and open up an area for future research, “he added.
All neurodegenerative diseases can be traced to problems with the way proteins are processed in the body. If proteins are improperly folded, they accumulate and accumulate in the tissues. These protein aggregates, as scientists call them, interfere with cell function and lead to neurodegenerative disorders.
Czyz and co-authors want to know if the introduction of certain bacteria into C. elegans worms will be followed by protein aggregation in worm tissues.
“We actually observe this. We have a way to mark the aggregates so that they glow green under the microscope. We have seen that worms colonized by certain types of bacteria are illuminated with aggregates that are toxic to tissues, while those colonized by control bacteria are not. were, ”Czyz said. “This has happened not only in the intestinal tissues where the bacteria are, but also throughout the body of the worms, in their muscles, nerves and even reproductive organs.”
Surprisingly, the offspring of the affected worms also show increased protein aggregation – although these offspring have never encountered the bacteria originally associated with the condition.
“It’s very interesting because it suggests that these bacteria generate some kind of signal that can be passed on to the next generation,” Cich said.
Worms colonized by “bad” bacteria also lose motility, a common symptom of neurodegenerative diseases.
“A healthy worm moves by rolling and rolling. When you take a healthy worm, it will disengage, just a device we use to treat these small animals. But worms with bad bacteria can’t do that because of the appearance of toxic protein aggregates, ”explained Walker, who developed this evaluation method.
“You could compare the choice to an obstacle: just as a person with a neurodegenerative disease will have trouble passing, the same goes for these worms, only on a much smaller scale,” Cheese added.
Fun fact: Human eyebrow or eyelash hair takes very good pictures.
“Worms are very delicate, so you need a tool that won’t damage them. They’re also transparent and have a simple body plan. Research like ours is possible because these worms usually feed on bacteria,” Cheese said.
“Worms are only a millimeter long, and each of them has exactly 959 cells,” Uncle said. “But in many ways they are very similar to us humans – they have intestines, muscles and nerves, but instead of being made up of billions of cells, each organ is just a handful of cells. They are like living tubes. Their small size allows us to experiment. in a much more controlled way and to answer important questions that we can apply in future experiments with higher organisms and ultimately with humans. “
Czyz’s lab is currently testing hundreds of strains of bacteria found in the human gut to see how they affect protein aggregation in C. elegans. The group also investigated how bacteria associated with neurodegeneration cause improper protein formation at the molecular level.
Czyz is also interested in the possible links between antibiotic-resistant bacteria and improper protein formation.
“Almost all of the bacteria we found associated with improper protein production are also linked to antibiotic-resistant infections in humans. It will take many more years of research before we can understand the link between antibiotic resistance and neurodegenerative diseases.” said Cheese.
Intestinal bacteria can modify the behavior of worms by influencing eating habits
Provided by the University of Florida
Quote: New evidence links intestinal bacteria and neurodegenerative conditions (2021, May 6), extracted on May 7, 2021 from https://medicalxpress.com/news/2021-05-evidence-links-gut-bacteria-neurodegenerative. html
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