Two previously unknown bacteria

Utrecht (Netherlands), January 12, 2023 – Investigators at University Medical Center Utrecht (Netherlands) and Yale University (USA) have isolated and characterized two new types of bacteria from patients with inflammatory bowel disease (IBD). previously unknown bacterial species, for which they were named mucilyticum allobicum And Allobaculum filiof intestinal microbiota from two different patients, the first members allobaculum sex in humans. In-depth characterization revealed that the strains were highly efficient at breaking down the protective mucosal layer of the intestine and eliciting strong immune responses. These findings highlight the potential role of bacteria in the pathogenesis of IBD and may contribute to preventative treatment in the future.

Intestine microbiota It contains thousands of bacterial species, many of which have not been cultured and tested in a laboratory. While the majority of these bacterial species are harmless or even contribute to our health, others are suspected of contributing to diseases such as colorectal cancer and Inflammatory bowel disease (ibd). Inflammatory bowel disease is a chronic inflammatory disorder that primarily consists of Crohn’s disease and ulcerative colitis and affects millions of people worldwide. Currently, it is still not clear what causes IBD, although it is believed that an unwanted immune response against the intestinal microbiota plays a critical role. Therefore, researchers at the University Medical Center (UMC) in Utrecht and Yale University (New Haven CT, USA) set out to jointly isolate and study novel bacteria isolated from IBD patients.

Two new types of bacteria

Using the latest technology “Culturology”In this study, the researchers were able to isolate two new types of bacteria from the intestines of patients with IBD. This bacterium officially named mucilyticum allobicum And Allobaculum filiare closely related to Gram-positive bacteria that grow in long chains and are the first members of F allobaculum The gender to be identified in humans. Genetic analysis revealed that they were distant cousins Erysipelothrix rhusiopathiaea pathogenic bacteria that infects various animals such as pigs, turkeys, and chickens, but also occasionally infects humans.

breakdown of the intestinal mucus layer

In two additional studies, the researchers then looked at properties mucilyticum allobicum and the role it may play during bowel disease. The bacteria were revealed to be highly efficient cleaners of intestinal mucus, the sticky protective layer that separates most intestinal bacteria from their host cells. Using a combination of genetic, proteomic and biochemical analyses, this was shown mucilyticum allobicum It releases a wide variety of enzymatic proteins during development that, one by one, cleave individual sugars from the myosin protein. These liberated polysaccharides can then be used to further support bacterial growth but may also reduce the protective function of the mucosal layer. Finally, in collaboration with a team Noah Palm, Ph.D From Yale University, it has been shown mucilyticum allobicum It caused intestinal inflammation in infected mice and interfered with the immune response to common healthy human bacteria.

Although it is still very preliminary, it is tempting to speculate that what is new allobaculum species, or other bacterial species with similar characteristics, play a role in gut inflammation as seen in IBD patients,” the principal investigator Marcel De Zoete, Ph.D (Department of Medical Microbiology, UMC Utrecht) guesses. “There is still a long way to go before we fully understand the role of the gut microbiota in the pathogenesis of IBD, but studies like these are important steps that may bring new insights and evidence for future preventive therapy.”

Publications

Van Muijlwijk GH, Rice TA, Flavell RA, Palm NW, de Zoete MR. mucilyticum allobicum s. november f Allobaculum fili s. November, two members of the novel allobaculum A genus isolated from the human intestine. International Journal of Systematic and Evolutionary Microbiology 2022 73 Jan(1):005635. doi:10.1099/ijsem.0.005635.

Van Muijlwijk GH, van Mierlo G, Jansen PWTC, Vermeulen M, Bleumink-Pluym NMC, Palm NW, van Putten JPM, de Zoete MR. Determination lubiculum myocoliticum as a novel human intestinal mucosa. gut microbes 2021 from January to December; 13 (1): 1966278. doi: 10.1080/19490976.2021.1966278.

Rice TA, Belika AA, Nguyen MT, Rosen C, Song D, Sonnert ND, Yang Wai, Kao Wai, Khitrapal V, Catanzaro GR, Martin L, Rashid SA, Leopold SR, Hau L, UX, Fan Dijk D, Ring AM, Flavell RA, De Zoet MR, Palm NW. Symbiotic interactions between species have nonlinear effects on host immunity. host cell microbe 2022 July 13; 30 (7): 988-1002.e6. doi: 10.1016/j.chom.2022.05.004.