Tag: constipation

Categories : GastrointestinalTags :

Scientists Discover a Form of Constipation Caused by Gut-drying Bacteria

On By ModernMedia

Two bacteria working together to break down intestinal mucus are identified as a contributing factor to chronic constipation

Scientists at Nagoya University in Japan have found two gut bacteria working together that contribute to chronic constipation. The duo, Akkermansia muciniphila and Bacteroides thetaiotaomicron, destroy the intestinal mucus coating essential for keeping the colon lubricated and faeces hydrated. Their excess degradation leaves patients with dry, immobile stool. This discovery, published in Gut Microbes, finally explains why standard treatments often fail for millions of people with chronic constipation.

Notably, the study shows that Parkinson’s disease patients, who suffer from constipation decades before developing tremors, have higher levels of these mucus-degrading bacteria. While constipation in Parkinson’s disease has traditionally been attributed to nerve degradation, these findings suggest that bacterial activity also plays a crucial role in the development of their symptoms.

Why mucin matters for digestion

Constipation is a very common digestive problem. Doctors have assumed it happens because of slow gut movement when our intestines are not moving food along fast enough. However, this explanation does not work for everyone.

Some people have constipation with no identifiable cause, referred to as chronic idiopathic constipation (CIC). Parkinson’s disease patients also face severe, treatment-resistant constipation, though it is clinically categorized separately from CIC. Many struggle with severe constipation for 20 or 30 years before they develop tremors and movement problems, but researchers did not know why until now.

Instead of focusing on nerve and muscle movement in the gut, the researchers examined the protective gel-like coating called colonic mucin, a substance in the large intestine that lines the intestinal walls and is found within stool. Colonic mucin keeps stool moist, helps it move smoothly through our digestive tract, and protects the intestinal wall from bacteria.

They found that two gut bacteria work in sequence to break down this mucin. B. thetaiotaomicron uses enzymes to remove protective sulfate groups from the mucin, and A. muciniphila then breaks down and consumes the exposed mucin.

Sulfate groups attached to colonic mucin molecules normally prevent bacteria from degrading them. When too much mucin is destroyed, stool loses moisture and becomes hard and dry, causing constipation. Because the problem is mucin loss, not slow gut movement, standard laxatives and gut motility drugs are often ineffective.

Researchers have identified a two-step bacterial process driving a new type of constipation: one bacterium removes protective sulfate groups while another consumes the exposed colonic mucin. Credit: Tomonari Hamaguchi, Nagoya University

A new frontier for gut health treatment

“We genetically modified B. thetaiotaomicron so it could no longer activate the enzyme sulfatase that removes sulfate groups from mucin,” Tomonari Hamaguchi, lead author and lecturer from the Academic Research & Industry-Academia-Government Collaboration Office at Nagoya University explained.

“We put these modified bacteria into germ-free mice together with Akkermansia muciniphila, and surprisingly the mice did not develop constipation; the mucin stayed protected and intact.”

The experiment proved that blocking the sulfatase enzyme prevents the bacteria from degrading mucin. Therefore, drugs that block sulfatase could treat bacterial constipation in humans.

For millions of patients with treatment-resistant constipation, including those with Parkinson’s disease, this discovery offers hope for new therapies that address the root microbial causes of their condition.

Source: Nagoya University

Categories : GastrointestinalTags :

A Touch-sensing Protein Helps the Gut to ‘Feel’

On By ModernMedia
Anatomy of the gut
Source: Pixabay CC0

New research published in the journal Gastroenterology has discovered that a touch-sensing protein is present in the gut, with its presence likely playing a key role in constipation. The protein, called Piezo2, was found using both human gut samples and mice is not just in our fingers, but also in our gut.

“Many people suffer from digestive issues on a daily basis, such as chronic constipation, however we still don’t understand the cause which underlies most of them,” said Lauren Jones, lead author and final year PhD student.

“Our research identified Piezo2 in cells that line the human digestive tract, allowing them to sense physical stimuli, such as touch or pressure, that would occur when food is present. The cells then respond by releasing serotonin to stimulate gut contractions and push the food along.”

Last year, international researchers Ardem Patapoutian and David Julius were awarded the Nobel Prize in Physiology or Medicine for their research on receptors responsible for the perception of touch and temperature, including the discovery of Piezo2, now known to be responsible for sensing light touch on our skin.

Of potential clinical importance, the Flinders research team also discovered that the levels of Piezo2 decrease in the gut with age, and found that if the protein was removed only from gut serotonin cells, gut motility slowed down in mice, causing constipation.

The authors say this could be a potential contributing factor to age-related constipation and provide a possible path to treatment.

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“Age-related constipation affects 1 in 2 adults over the age of 80, whilst constipation generally affects almost everyone at some point throughout their life,” says Ms Jones.

“It’s therefore extremely important we increase our understanding of the underlying mechanisms, so that we can find targeted solutions to improve the quality of life of the many people who suffer daily from various gut disorders, including constipation.

“This research provides the building blocks for both further research and the development of highly specific treatments to reduce the impacts of constipation.”

The authors say that, though more studies are needed to firmly link Piezo2 to constipation, the research overall is an important advancement into our understanding of gut physiology, opening up new targets for the treatment of digestive issues.

The insights allow for reduced side effects, explained Ms Jones: “More specifically, we now have the potential to create treatments that are taken orally and only directly impact these cells that line the gut, therefore significantly reducing side effects typically seen with many of the current medications.”

Source: News-Medical.Net