SEP 02, 2019 8:45 AM PDT

Using Peptides to Remodel the Microbiome

WRITTEN BY: Carmen Leitch

Now that we know so much more about the bacteria we carry in our bodies, it may be possible to start using that bacteria to improve our health. The food and stuff we take in can have a powerful impact on the microbes in our gut, which in turn have a powerful influence on us. The gut microbiome has been linked to many diseases including some of the most common - obesity, cancer, and heart disease. Researchers are starting to identify molecules that can help remodel unhealthy gut microbiomes from microbial communities that encourage disease to healthy ones.

"The gut microbiome contains hundreds of different species of bacteria and is where the largest concentration of bacteria living in us resides," said researcher M. Reza Ghadiri, Ph.D. "If we all ate a healthy diet, exercised and didn't age, we wouldn't have problems with our gut microbiome and many diseases. But, that's not how all people live. Current methods aimed at improving the makeup of gut microbiomes have involved prebiotics, probiotics or drug therapies. Our goal was to take a totally new approach - to remodel the microbiome."

Ghadiri's research team created a class of molecules, originally to kill bacteria, called self-assembling cyclic D, L-α-peptides. These short chains of amino acids aren’t natural and they can selectively target different types of bacteria in specific ways.

"Our hypothesis was that instead of killing bacteria, if we could selectively modulate the growth of certain bacteria species in the gut microbiome using our peptides, more beneficial bacteria would grow to fill the niche, and the gut would be 'remodeled' into a healthful gut," Ghadiri explained. "Our theory was that process would prevent the onset or progression of certain chronic diseases."

Illustration credit: Pixabay

They tested their idea in a mouse model of cardiovascular disease; the mice lack a receptor for LDL cholesterol. This strain of mouse is commonly used to test drugs that reduce cholesterol levels.

"These mice have been bred to thrive on low-fat diets, but when they are fed a diet high in saturated fat - a so-called Western diet - they develop high plasma cholesterol, especially the LDL or bad type," noted Ghadiri. "Within ten to twelve weeks, they develop plaques in their arteries such as you would find in atherosclerosis patients."

The researchers used a wide screen to identify the peptides they wanted to test on the mice. Then they created a model mouse microbiome and found the peptides that were most able to remodel it to resemble a microbiome that would be carried by mice on a low-fat diet. Next, they tested the candidate peptides on mice in three groups; one group got a low-fat diet, another got the high-fat Western diet, and the last group got a Western diet with one of the two peptides.

"Mice fed the Western diet with our peptides had a 50 percent reduction in total plasma cholesterol, and there was no significant plaque in the arteries, compared to the mice fed a Western diet and no peptides," Ghadiri revealed. "We also saw suppressed levels of molecules that increase inflammation and rebalanced levels of disease-relevant metabolites. These mice resembled those on a low-fat diet."

Ghadiri suspects that these effects are mediated by genes that are involved in inflammation, and in bile acids, which would impact cholesterol metabolism.

"This is the first time anyone has shown that there are molecules to purposefully remodel the gut microbiome and turn an unhealthful gut into a more healthful one," he added. "This opens up clear therapeutic possibilities. We can sequence the guts of individuals and eventually develop therapies."

Learn more about the microbiome from the NIHvcast above.


Sources: AAAS/Eurekalert! via American Chemical Society

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
OCT 26, 2021
Earth & The Environment
Glomalin, The Protein that Can Heal the Earth
OCT 26, 2021
Glomalin, The Protein that Can Heal the Earth
Soil quality is growing ever more important as we attempt to feed the growing world population. Our soils are being degr ...
NOV 01, 2021
Cancer
Gut Microbiota Promotes Resistance to Prostate Cancer Therapy
NOV 01, 2021
Gut Microbiota Promotes Resistance to Prostate Cancer Therapy
  The American Cancer Society estimates that nearly 250,000 men in the United States will be diagnosed with prostat ...
NOV 11, 2021
Immunology
Malaria Researchers Make a Surprising Antibody Find
NOV 11, 2021
Malaria Researchers Make a Surprising Antibody Find
Researchers looking into the immunology of malaria infections have made an unexpected find that could ultimately lead to ...
NOV 07, 2021
Genetics & Genomics
New Model Teaches Us More About Why the Delta Variant is So Infectious
NOV 07, 2021
New Model Teaches Us More About Why the Delta Variant is So Infectious
When the COVID-19 pandemic began to impact the world, researchers everywhere sprang into action. But studying an infecti ...
NOV 30, 2021
Plants & Animals
"Once-in-a-Generation" Discovery of New Tardigrade Species in Amber
NOV 30, 2021
"Once-in-a-Generation" Discovery of New Tardigrade Species in Amber
Tardigrades might be the toughest little creatures around. These minuscule eight-legged vertebrates can survive in outer ...
DEC 13, 2021
Cell & Molecular Biology
The Body Can Use Fat to Fuel the Fight Against Bacterial Infection
DEC 13, 2021
The Body Can Use Fat to Fuel the Fight Against Bacterial Infection
A new study reported in Nature Communications has shown how the body might use fat as fuel in the battle against a Salmo ...
Loading Comments...