Infection with worms counters inflammatory bowel diseases (IBD) by triggering immune responses that change the mix of bacteria, or microbiome, in the gut. This is according to a study published online April 14 in the journal Science.
The study results support the hygiene hypothesis which, in the case of IBD, argues that the absence of exposure to worms in
In the newly published study, a team led by researchers from NYU Langone Medical Center found that mice infected with intestinal worms experienced as much as a
«Our findings are among the first to link parasites and bacteria to the origin of IBD, supporting the hygiene hypothesis," says study
Also among the study’s key findings was that people in rural parts of Malaysia, a region known to have low rates of IBD but a high incidence of worm infections, had significantly more Clostridia and fewer Bacteriodes in their microbiomes than people comprising a nearby urban population. In addition, the researchers found that people treated and dewormed had less Clostridia and more Bacteriodes.
«Our study could change how scientists and physicians think about treating IBD," says study
Loke also led a study, published in the journal PLOS Pathogens in 2012, which found that giving worm eggs to monkeys protected them from the simian version of IBD. Worm eggs may be able to trick the immune system into thinking it has a worm infection, and to trigger a specific kind of
As part of the new study, the NYU Langone team fed between 10 and 15 parasitic whipworm eggs to mice lacking a gene called NOD2, which is tied to several immune disorders, including IBD. After the worms matured, the investigators measured the amount of Bacteroides and Clostridia in the mice’s intestines and stool and noted the presence or absence of IBD. They found that many of the symptoms of IBD, such as intestinal bleeding and ulceration, went away along with almost all Bacteroides, while the Clostridia levels increased.
For another part of the study, the researchers compared the bacteria found in 75 members of the Orang Asli indigenous people in rural Malaysia to those of 20 people living in urban Kuala Lumpur. Researchers found that rural people had much fewer Bacteroides than city dwellers.
Cadwell says he and Loke plan to investigate how Clostridia outcompete Bacteroides, and search for harmless Clostridia species that can still induce this effect. In addition, they intend to explore alterations to gut bacteria by worm infections as the foundation of treatments for several inflammatory diseases.
Funding support for the study was provided by National Institute of Health grants DK103788, DK093668, and AL093811, and by grants from the Burroughs Wellcome Fund and Dr. Bernard Levine.
In addition to Cadwell and Loke, other NYU Langone researchers included Deepshika Ramanan, BS; Rowann Bowcutt, PhD; Zachary Kurtz, BS; Martin Blaser, MD; and Mei San Tang, MD. Further research support was provided by Soo Ching Lee, PhD, and Yvonne Al Lim, PhD, at the University of Malaya in Malaysia; Kenya Honda, PhD, at the Center for Integrative Medical Sciences in Yokohama, Japan; Richard Bonneau at the Simons Foundation in New York; and William C. Cause, PhD, at the Center for Immunity and Inflammation at New Jersey Medical School.Source: http://www.newswise.com/articles/worm-infection-counters-inflammatory-bowel-disease-by-drastically-c...