MAR 17, 2022 1:01 AM PDT

How Bacteria Can Keep Intestinal Inflammation in Check

WRITTEN BY: Carmen Leitch

We need bile acids to help us digest food and absorb nutrients. New research has shown how bile acids modified by bacteria also play a critical role in the regulation of immunity and inflammation in the gut. This work, which has been reported in Nature as well as Cell Host & Microbe, may shed new light on ulcerative colitis and Crohn's disease. The presence of certain gut bacteria and the production of their immune-influencing molecules was also determined to be significantly decreased in inflammatory bowel disease (IBD) patients.

Image credit: Pixabay

The gut hosts a community of trillions of microbes that have been shown to have a crucial impact on human health, and our immune system. This work has provided "a novel mechanistic insight into how these bacteria work to mediate immune regulation in the gut," said co-study leader Jun Huh, associate professor of immunology at Harvard Medical School (HMS).

Research that utilized stool samples from a mouse model and human volunteers revealed more about the microbes that influence immunity.

Gut bacteria were found to convert a secondary bile acid called lithocholic acid into another molecule, 3-oxoLCAm and a common gut metabolite called isolithocholic acid (isoLCA). These bile acids can then interfere with the function of cells called T helper cells expressing interleukin-17A (TH17 cells). Both 3-oxoLCA and isoLCA suppressed TH17 cell differentiation. Thus, gut bacteria and bile acids they generate could be related to inflammatory disorders of the gut.

The researchers also determined that people with disorders that involve inflammation in the gut, such as ulcerative colitis or Crohn's disease, have far fewer anti-inflammatory molecules, and not as many bacterial genes that encode for those molecules.

If small molecules can be produced that can mimic the effect of these bacterial molecules,  or the gut microbiome can be supplemented with the right kind of bacteria, it may be possible to treat inflammatory disorders in the gut.

The "molecules and the bacterial genes that we discovered that produce these molecules are reduced in patients with IBD," said study co-leader Sloan Devlin, assistant professor of biological chemistry and molecular pharmacology at HMS. "Restoring the presence of either the compounds or the bacteria that make them offers a possible therapeutic avenue to treat a range of inflammatory diseases marked by these deficiencies and affecting millions of people worldwide."

Sources: Harvard Medical School, Nature, Cell Host & Microbe

About the Author
BS
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
JUL 05, 2022
Immunology
A New Type of Universal Flu Vaccine
JUL 05, 2022
A New Type of Universal Flu Vaccine
Researchers have created a new 'universal' flu vaccine, which is directed against type A influenza viruses. It w ...
JUL 12, 2022
Drug Discovery & Development
Nitric Oxide Reduces Hospital Stay of Pregnant Women with COVID-19
JUL 12, 2022
Nitric Oxide Reduces Hospital Stay of Pregnant Women with COVID-19
High-dose nitric oxide can reduce the length of hospital and ICU stay, as well as the need for supplemental oxygen, amon ...
JUL 19, 2022
Clinical & Molecular DX
As Rates of Thyroid Cancer Continue to Increase, Researchers Question Why
JUL 19, 2022
As Rates of Thyroid Cancer Continue to Increase, Researchers Question Why
Beginning in the early 1990’s, rates of thyroid cancer began to drastically increase. Though this trend has contin ...
JUL 22, 2022
Coronavirus
Researchers Say Nasal Boosters Will be Important to Stopping COVID
JUL 22, 2022
Researchers Say Nasal Boosters Will be Important to Stopping COVID
The SARS-CoV-2 virus has continued to evolve since the start of the pandemic, and we've moved down the list of variants ...
AUG 02, 2022
Neuroscience
Could Common Viruses be Triggering Alzheimer's?
AUG 02, 2022
Could Common Viruses be Triggering Alzheimer's?
Recent allegations of research misconduct have called years of Alzheimer's research into question. The controversy surro ...
AUG 11, 2022
Cell & Molecular Biology
A Natural Compound Stimulates Repair in Muscle Tissue
AUG 11, 2022
A Natural Compound Stimulates Repair in Muscle Tissue
When tissues in our bodies experience damage, there are various repair mechanisms that can be employed. When muscles are ...
Loading Comments...