Researchers have developed a method to restrict the mobility of gut bacteria that are linked to chronic inflammatory bowel disorders that cause stomach and intestinal ulcers, an advance that may lead to new vaccine development strategies. The researchers, including those from Inserm -- The Institut national de la sante et de la recherche medicale -- in France, said patients with inflammatory bowel diseases had reduced diversity of gut bacteria, and excessive levels of microbes with a protein called flagellin, which favours their mobility.
They said the intestinal mucous layers naturally produced antibodies directed against the bacterial flagellin, spontaneously developing immune protection against bacteria that try to penetrate and pass through this barrier. In their study, published in the journal Nature Communications, the scientists stimulated the antibodies working against the flagellin protein in order to reduce the presence of the bacteria expressing it in the gut.
They injected mice with flagellin via their body cavity, and induced an immune response in the rodents against the protein -- similar to how vaccines work. This led to a marked increase in the anti-flagellin antibodies in the mice, particularly in their intestinal mucus layers, the study noted.
The researchers used a protocol to induce chronic intestinal inflammation in the mice, and observed that immunising against flagellin provided the rodents significant protection from gut related diseases. The findings of the study noted that the immunisation lowered the levels of bacteria with the flagellin protein, and also led to their absence in the intestinal mucosa, compared to the unvaccinated group.
"This vaccine strategy can be envisaged in humans, because such abnormalities of the microbiota have been observed in patients with inflammatory and metabolic diseases. With this in mind, we are currently working on a means of locally administering flagellin to the intestinal mucosa," said study co-author Benoit Chassaing from Inserm.