OSAKA--In a step toward a new anti-obesity vaccine, researchers have reported that mice that were given an immunization that controls intestinal bacteria and placed on a high-fat diet became less obese than non-immunized mice.

“We have created a new type of vaccine, completely different from the existing vaccines,” Satoshi Uematsu, professor of the Department of Immunology and Genomics at the Osaka City University Graduate School of Medicine, one of the researchers, announced on Aug. 23.

“By reducing particular types of intestinal bacteria, it is possible that the findings can lead to the development of an anti-obesity vaccine, with which people can eat and not get fat,” Uematsu said of the significance.

The team of researchers from Osaka City University and the University of Tokyo focused on Clostridium ramosum, a commensal microbe associated with obesity and diabetes. The findings were recently published in Gastroenterology, a journal of the American Gastroenterological Association.

In the experiments on mice, the researchers created a vaccine that activates immunity in the intestinal mucosa.

They put intestinal bacteria from obese individuals into pathogen-free mice. The mice were then placed on a high-fat diet.

The researchers found that intestinal bacteria in the nine immunized mice became reduced by defecation, and the mice gained 12 percent less weight than the seven non-immunized mice.

In the body of the immunized mouse, intestinal bacteria were reduced and the activities of absorbing glucose in the small intestine and other organs did not become intensified. The researchers believe that such observation promises a certain level of benefit in preventing diseases such as obesity and diabetes.

The vaccine works to boost the body’s immune system in the mucosa of intestines and digestive organs. The vaccination makes cells in the body to memorize the activity of the immune system. The cells then can react to pathogens and antigens and activate antibody proteins.

The research team has patented the system and undertaken the joint study with pharmaceutical companies.

The team has also confirmed that the system works to prevent pneumococcal infection and diarrhea caused by choleragen.

The research results can be read at the journal’s website:

https://doi.org/10.1053/j.gastro.2019.08.021