Upcoming Webinars Archived Webinars Training Vitals Host A Webinar About Get Updates Contact

Microbes Impact Organ Transplant Success

XTALKS VITALS NEWS

Organ Transplant

Some have hypothesized that the increased risk of organ transplant rejection can be explained by the fact that the skin, lungs and intestines all contain a unique microbiome composed of a number of different microorganisms.

Share this!

June 23, 2016 | by Sarah Massey, M.Sc.

The microbes that live on the skin and in the digestive system have an effect on the body’s ability to accept transplanted organs, according to a new study. The researchers found that mice treated with antibiotics prior to receiving a skin graft, survived twice as long as those that were not treated prophylactically.

Furthermore, mice raised in a sterile environment also had better outcomes following transplantation surgery. If these germ-free mice were exposed to microbes from traditionally-raised mice, they rejected their skin graft more quickly.

Interestingly, if microbes that survived the antibiotic treatment in mice were given to the sterile mice, they retained the skin graft for longer. This result – which was published in The Journal of Clinical Investigation – suggests that the composition of the microbiome has a marked effect on the success or failure of an organ transplant.

“The species that form the community of microbes colonizing the mice – and supposedly humans too – have different effects,” said Dr. Maria-Luisa Alegre, professor of medicine at the University of Chicago and co-senior author of the study. “One community of bacteria from the normal mice is capable of inducing accelerated rejection of a transplant, but another community of bacteria, those that are left after antibiotics, doesn't have that capacity.”

Organs that come in contact with the outside world – including the skin, lungs and intestines – have poor transplant success rates compared to internal organs, including hearts and kidneys. This outcome has been seen in both animal models and in clinical settings.

Tweet: Risk of organ rejection for skin, lungs, intestines linked to microbiome http://ctt.ec/6phEf+

Some have hypothesized that this increased risk of rejection can be explained by the fact that the skin, lungs and intestines all contain a unique microbiome composed of a number of different microorganisms. To test this hypothesis, Alegre and her colleagues treated organ donor, and recipient mice, with antibiotics for a 10 day period leading up to the skin graft surgery.

Mice who were given antibiotics before receiving the skin graft survived for 53 days, compared to 27 days in the control mice. The specific immune response mounted against the graft in these antibiotic-treated mice was also found to be significantly reduced.



Mice that were raised in a sterile environment also showed a longer survival time compared to the control. Fecal microbiota transplants from conventionally-raised mice accelerated the rate of graft rejection in the germ-free mice. Surprisingly, when germ-free mice were given fecal microbiota transplants from mice that were given antibiotics, the mice took a longer period of time to reject the skin graft.

These results highlight the effect of different microbial communities on organ transplant outcomes. Other research has also found that mice pre-treated with antibiotics before receiving a heart transplant survived for longer – an interesting result as the heart is not colonized by any microbes.

After performing a genetic analysis of the microbes present on the skin of animals treated with antibiotics, the researchers found that the number of bacteria was comparable to that found on untreated mice. They did however, find that there was significantly less variety in the types of bacterial species present on the skin after antibiotic treatment.

“In terms of the total number of bacteria that are present, it's the same before and after antibiotics,” said Alegre. “But instead of 1,000 species, let's say you have just 500 after treatment. So it's not the bacterial load that makes the difference, it's the composition of the bacterial community.”

According to the researchers, a better understanding of the specific microbes which act to induce or suppress the immune response, could lead to better transplant patient outcomes. For example, the knowledge could be used to design narrow-spectrum antibiotics which target only those bacteria involved in the immune response.

Conversely, probiotics could be developed to increase the proportion of bacteria which suppress the immune system. As it’s currently unknown which species have an effect on the body’s response to a transplanted organ, these possible research applications are not yet possible.

“We have evolved to cohabit effectively with our microbes, and they are very beneficial,” said Alegre. “We need them. They make vitamins we need. They digest foods we can't digest. They help maintain our health by poising our immune system for fighting infections. So we have to be careful with anything that's going to alter that balance.”


Keywords: Organ Transplant, Microbes, Antibiotics


| NEXT ARTICLE | MORE NEWS | BLOGS | VIDEOS | POLLS & QUIZZES | WEBINARS |

Share this with your colleagues!

MORE NEWS
Insurance Coverage Under the Affordable Care Act Supports Clinical Trial Enrollment, Says Study

July 20, 2017 - Since the Patient Protection and Affordable Care Act (ACA) was passed in 2010, insurance approval for patients wishing to participate in oncology clinical trials has increased, according to a recent study published in the journal, Clinical Cancer Research.

Featured In: Clinical Trial News


FDA Approves Puma Biotechnology’s Extended Adjuvant Therapy for Breast

July 19, 2017 - Puma Biotechnology’s breast cancer drug Nerlynx (neratinib) has been approved by the US Food and Drug Administration (FDA).

Featured In: Biotech News


CAR-T Cell Therapy Shows Promise as Leukemia Treatment in Early Stage Clinical Trial

July 19, 2017 - About 70 percent of clinical trial participants with chronic lymphocytic leukemia experienced tumor shrinkage after being treated with CAR-T immunotherapy, according to researchers at Fred Hutchinson Cancer Research Center.

Featured In: Clinical Trial News


LEAVE A COMMENT
 
  
THE XTALKS VITALS INDUSTRY BLOG

Manufacturing Control Strategies: What Pharmaceutical and Biotech Companies Need to Know

REGISTER FOR THESE WEBINARS

Outsourcing Pharmacovigilance: Pros and Cons and Lessons Learned


EDC and eSource: Combined for Better Data and Faster Insights


Using Model Reduction to Bridge the Quality Systems Pharmacology-Pharmacometrics Divide


How to Maximize Your Non-GLP Toxicology Studies: A Guide for Optimal Design and Methodology


Copyright © 2016-2017 Honeycomb Worldwide Inc.