Could the cure for IBD be inside your mouth?

June 16, 2020

While many people put off their regular trips to the dentist, recent research has shown that the consequences of doing so may go beyond cavities and root canals. From heart disease to diabetes, poor oral health is often a reflection of a person's overall health and may even be the cause of systemic disease.

A new collaborative study from the U-M Medical and Dental Schools reveals that inflammatory bowel disease (IBD), which included Crohn's disease and ulcerative colitis and afflicts an estimated 3 million adults in the U.S., may be the latest condition made worse by poor oral health.

Nobuhiko Kamada, Ph.D., assistant professor of internal medicine in the division of gastroenterology, has been studying the gut microbiome--the collection of bacteria that are normally present in the gut-- for years. He noted an emerging link in research literature between an overgrowth of foreign bacterial species in the guts of people with IBD--bacteria that are normally found in the mouth. "I decided to approach the dental school to ask the question, does oral disease affect the severity of gastrointestinal diseases?" says Kamada.

The new mouse study, published in Cell, shows two pathways by which oral bacteria appear to worsen gut inflammation.

In the first pathway, periodontitis, the scientific name for gum disease, leads to an imbalance in the normal healthy microbiome found in the mouth, with an increase of bacteria that cause inflammation. These disease-causing bacteria then travel to the gut.

However, this alone may not be enough to set off gut inflammation. The team demonstrated that oral bacteria may aggravate gut inflammation by looking at microbiome changes in mice with inflamed colons.

"The normal gut microbiome resists colonization by exogenous, or foreign, bacteria," says Kamada. "However, in mice with IBD, the healthy gut bacteria are disrupted, weakening their ability to resist disease-causing bacteria from the mouth." The team found that mice with both oral and gut inflammation had significantly increased weight loss and more disease activity.

In the second proposed pathway, periodontitis activates the immune system's T cells in the mouth. These mouth T cells travel to the gut where they, too, exacerbate inflammation. The gut's normal microbiome is held in balance by the action of inflammatory and regulatory T cells that are fine-tuned to tolerate the resident bacteria. But, says Kamada, oral inflammation generates mostly inflammatory T cells that migrate to the gut, where they, removed from their normal environment, end up triggering the gut's immune response, worsening disease.

"This exacerbation of gut inflammation driven by oral organisms that migrate to the gut has important ramifications in emphasizing to patients the critical need to promote oral health as a part of total body health and wellbeing," says co-author William Giannobile, DDS, the William K and Mary Anne Najjar professor of dentistry and chair of the department of periodontics and oral medicine at the U-M School of Dentistry.

The study has implications for novel treatments for IBD, necessary because "far too many patients still fail medications, leading to reduced quality of life and eventual surgery," says study co-author Shrinivas Bishu, M.D., assistant professor of gastroenterology. "This study importantly implies that clinical outcomes in IBD may be improved by monitoring oral inflammation - an intriguing concept."
-end-
Paper cited: "The intermucosal connection between the mouth and gut in commensal pathobiont-driven colitis," Cell. DOI: 10.1016/j.cell.2020.05.048

Michigan Medicine - University of Michigan

Related Bacteria Articles from Brightsurf:

Siblings can also differ from one another in bacteria
A research team from the University of Tübingen and the German Center for Infection Research (DZIF) is investigating how pathogens influence the immune response of their host with genetic variation.

How bacteria fertilize soya
Soya and clover have their very own fertiliser factories in their roots, where bacteria manufacture ammonium, which is crucial for plant growth.

Bacteria might help other bacteria to tolerate antibiotics better
A new paper by the Dynamical Systems Biology lab at UPF shows that the response by bacteria to antibiotics may depend on other species of bacteria they live with, in such a way that some bacteria may make others more tolerant to antibiotics.

Two-faced bacteria
The gut microbiome, which is a collection of numerous beneficial bacteria species, is key to our overall well-being and good health.

Microcensus in bacteria
Bacillus subtilis can determine proportions of different groups within a mixed population.

Right beneath the skin we all have the same bacteria
In the dermis skin layer, the same bacteria are found across age and gender.

Bacteria must be 'stressed out' to divide
Bacterial cell division is controlled by both enzymatic activity and mechanical forces, which work together to control its timing and location, a new study from EPFL finds.

How bees live with bacteria
More than 90 percent of all bee species are not organized in colonies, but fight their way through life alone.

The bacteria building your baby
Australian researchers have laid to rest a longstanding controversy: is the womb sterile?

Hopping bacteria
Scientists have long known that key models of bacterial movement in real-world conditions are flawed.

Read More: Bacteria News and Bacteria Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.