Crohn’s disease is an inflammatory disease that
affects the digestive tract. Symptoms include severe abdominal pain, diarrhea,
weight loss, and fatigue. The disease results from the immune system responding
abnormally to gut microbial antigens. Previous studies have concentrated on the
bacterial community in the intestines. The authors conducted studies that
focused on the overlooked fungal community.
The
researchers analyzed fecal samples from patients with and without Crohn’s
disease. The samples from those with Crohn’s disease contained strong
fungal-bacterial interactions, specifically two bacteria (Escherichia coli and Serratia
marcescens) and one fungus (Candida
tropicalis). Additionally, Candida
tropicalis was more abundant in patients with Crohn’s disease than their
relatives who did not have the disease. They also found that the abundance of
beneficial bacteria decreased in Crohn’s disease patients.
This
study shows for the first time that bacterial species in the gut, as well as
fungi, play a role in the disease. They discovered how the bacteria and fungi
interact. Together, they form a biofilm, which is a thin, sticky layer of
microorganisms. The film attaches to sections of the gut, which could be
triggering the inflammation that causes the symptoms attributed to Crohn’s
disease. The researchers also are the first to include Serratia marcescens as a contributor. In a previous study conducted
by another research group (Ochieng et al.), S.
marcescens was revealed to interact with epithelial cells of the intestine in
cultures and produce effects that could play a large role in Crohn’s disease by
worsening the episodes of inflammation in the intestine.
A person’s diet and
environment also contribute to the microorganisms present in the intestines. However,
the addition of new information regarding the role bacteria and fungi play in
the development of Crohn’s disease opens the door for the development of new
treatments. More research must be done, but as more is learned about the
disease, more can be done to help those suffering from it.
Resources:
To learn more about Crohn’s disease visit:
https://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0022801/
https://www.sciencedaily.com/releases/2016/09/160920151435.htm
References:
G.
Hoarau, P. K. Mukherjee, C. Gower-Rousseau, C. Hager, J. Chandra, M. A.
Retuerto, C. Neut, S. Vermeire, J. Clemente, J. F. Colombel, H. Fujioka, D.
Poulain, B. Sendid and M. A. Ghannoum. Bacteriome and Mycobiome Interactions
Underscore Microbial Dysbiosis in Familial Crohn’s Disease. mBio,
September 2016 DOI: 10.1128/mBio.01250-16
John B Ochieng, Nadia Boisen,
Brianna Lindsay, Araceli Santiago, Collins Ouma, Maurice Ombok, Barry Fields, O
Colin Stine, and James P Nataro. Serratia marcescens is injurious to
intestinal epithelial cells. Gut Microbes.
5.6, 2014.
http://www.tandfonline.com/doi/full/10.4161/19490976.2014.972223
Hey Abby,
ReplyDeleteI took a class in immunology a couple years ago and Crohns disease was covered extensively to talk about detrimental immune responses. Even after that class I could not explain the cause of Crohns. Your blog cleared that up. I do wonder if people had a weakened immune system and did not developed Crohns disease, how detrimental would the bio film in the gut be to the person? If it disrupted digestion enough to cause nutritional imbalances or caused enough irritation to hurt the body I understand the natural response that leads to Crohns.But if it does more harm then good iI wonder how Crohns developes.
It seems to me that Crohns disease is pretty common. I wonder what preventative measures could now be produced by understanding these recent studies.
ReplyDeleteAbby,
ReplyDeleteI have an aunt that is diagnosed with Crohn's and sometimes she has intense pain and finds it hard to do simple day-to-day tasks. She has to constantly watch her diet because certain things she eats, especially cheese, irritates her stomach. I think that knowing the why a disease occurs is important in designing treatments that can cure or mask some of the effects. In the case of Crohn's, because it can be really debilitating, knowing that biofilms consisting of both bacteria and fungi could be a source of inflammation in these individuals can lead scientists to develop novel treatments that target these biofilms. I think the most challenging part of development of the novel treatments would be trying to pinpoint why these individuals are prone to having more of the C. tropicalis than the average person.
It's confusing...do these changes in gut microflora cause the symptoms of Crohn's disease or do they result from them? Or maybe a little of both in some kind of feedback loop?
ReplyDeleteIt is tricky because Crohn's disease is characterized by microbial imbalance in the gut, but the interactions of the gut microbiota result in biofilms that trigger inflammation. So it is more of a revolving door. More research needs to be conducted to determine the specific cause and effect relationship.
Delete