Antibiotics, at the origin of intestinal inflammation

In the lives of scientists, lucky coincidences often occur that make their occupation exciting. as it happened to the doctor Koji Atarashi of Keio University in Tokyo, Japan, upon discovering the very possible relationship between oral bacteria and inflammatory diseases of the intestine.

The finding occurred when significant amounts of oral bacteria were found in the fecal samples of the patients. with ulcerative colitis and Crohn’s disease. Discovering this fact, they obtained samples of bacteria from patients suffering from intestinal inflammation and inoculated them into mice; The results, published in the journal ScienceThey were amazing.

Antibiotic-resistant mouth bacteria cause inflammation

In the first experiment, the researchers took saliva from patients with ulcerative colitis and Crohn’s disease and inoculated it into mice with intestines clean of any germs. some mice developed intestinal inflammation, comparable to intestinal disorders in humans.

Looking more closely, they found that a bacterium, the Klebsiella pneumoniae, played an important role in the inflammatory reaction. These bacteria usually live in the mouth and reach the intestine with the liter and a half of saliva that we swallow daily.

However, when the microbiota is healthythey do not colonize the intestine –although there may be a small reservoir– and they are not found in the feces.

Microbiota altered by antibiotics

The research got even more interesting when the researchers inoculated the bacteria directly into the intestines of healthy mice that had not received any prior treatment. These types of mice did not show any symptoms of inflammation. However, if they were treated with antibiotics, then inflammation appeared in the intestines of the animals.

This demonstrated very clearly that Klebsiellas can proliferate after antibiotic treatment and thereby establish the basis for inflammatory bowel disease. And it is that Klebsiellas can be very resistant to a large number of antibiotics.

Other studies have confirmed that people with inflammatory bowel diseases have more Klebsiellas in their intestines than healthy people, and also that his condition worsens after antibiotic treatments.

Pathogenic bacteria replace beneficial ones

According to the researchers, Klebsiellas strains from saliva activate TH1 lymphocytes in the intestine, which are associated with inflammation accompanying the immune response. As the researchers noted, “Antibiotic-resistant Klebsiella can gradually replace part of the microbiota in genetically predisposed patients, leading to significant inflammation in the gut.”

In addition, in people with suppressed immunity, these bacteria can cause urinary tract, lung, and blood infections that they can be deadly.

The authors believe that a treatment that controls the growth of these oral bacteria could be an effective therapeutic strategy to treat inflammatory bowel disease and many other disorders.

Specifically, they propose to identify and promote the growth of beneficial bacteria of the intestinal microbiota that may offer resistance to the development of Klebsiellas.