(Press-News.org) ROCHESTER, Minn . -- A Mayo Clinic researcher, along with his collaborators, has shown that an individual's genomic makeup and diet interact to determine which microbes exist and how they act in the host intestine. The study was modeled in germ-free knockout mice to mimic a genetic condition that affects 1 in 5 humans and increases the risk for digestive diseases. The findings appear in the Proceedings of the National Academy of Sciences.
"Our data show that factors in the differences in a host's genetic makeup -- in this case genes that affect carbohydrates in the gut -- interact with the type of food eaten. That combination determines the composition and function of resident microbes," says Purna Kashyap, M.B.B.S., a Mayo Clinic gastroenterologist and first author of the study. He is also a collaborator in the Microbiome Program of the Mayo Clinic Center for Individualized Medicine.
Significance of the Findings
Roughly 20 percent of humans lack the gene that encodes proteins for processing a specific carbohydrate, a sugar in the intestinal mucus called fucose. The interaction shown by the research team is valuable because many bacteria are adept at utilizing carbohydrates such as fucose, which are abundant in the gut. Confronted with diets that have little or no complex plant sugars, these bacteria are forced to change their function, especially in hosts that lack fucose. This was seen with the altered metabolic gene expression of one of the key microbes in the gut -- Bacteroides thetaiotaomicron. Changes in microbial membership or function as demonstrated in this study may, in turn, foster a "digestive landscape" that can promote inflammatory conditions such as Crohn's disease.
The microbiome represents millions of microbes in the gut and elsewhere in the body. They perform specialized functions to help keep metabolism in balance. Whether in humans or other animals, the microbial combination is unique and must function well with the individual's genome and diet for a healthy existence.
###
Additional researchers on the study include Angela Marcobal, Ph.D.; Samuel Smits; Erica Sonnenburg, Ph.D.; Elizabeth Costello, Ph.D.; Steven Higginbottom; Susan Holmes, Ph.D.; David Relman, M.D.; and Justin Sonnenburg, Ph.D.; all of Stanford University; Luke Ursell, University of Colorado at Boulder; Rob Knight, Ph.D., Howard Hughes Medical Institute and University of Colorado at Boulder; Steve Domino, M.D., Ph.D., University of Michigan; and Jeffrey Gordon, M.D., Washington University.
The research was supported by the National Institutes of Health, the Crohn's & Colitis Foundation of America, the Walter and Idun Berry Foundation, and the Thomas and Joan Merigan Endowment at Stanford.
About Mayo Clinic
Mayo Clinic is a nonprofit worldwide leader in medical care, research and education for people from all walks of life. For more information, visit http://www.mayoclinic.org/about and http://www.mayoclinic.org/news.
Journalists can become a member of the Mayo Clinic News Network for the latest health, science and research news and access to video, audio, text and graphic elements that can be downloaded or embedded.
Genetic makeup and diet interact with the microbiome to impact health
2013-09-25
ELSE PRESS RELEASES FROM THIS DATE:
Researchers develop model to study human response to infections that cause peptic ulcers
2013-09-25
Researchers at the Virginia Bioinformatics Institute at Virginia Tech have developed a new large animal model to study how the immune system interacts with the stomach bacterium Helicobacter pylori, the leading cause of peptic ulcer disease.
The discovery in the October edition of the journal Infection and Immunity may inform changes in the ways doctors treat patients. An estimated 4 million Americans have sores in the stomach lining known as peptic ulcers, according to the American Gastroenterological Association.
Although the bacterium is found in more than half ...
Survey reveals improving salary and employment picture for chemists
2013-09-25
With the U.S. economy slowly trudging back from recession and uncertainties remaining about government sequestration, the employment and salary snapshot for chemists and chemical engineers in 2013 shows that salaries and the job market are improving. Results of the American Chemical Society's annual survey of its members are the topic of the cover story in Chemical & Engineering News, ACS' weekly newsmagazine.
Sophie Rovner, assistant managing editor of C&EN, notes that the survey results are encouraging. Salaries and employment for chemists are on the rise. Full-time ...
Alpine archaeology reveals high life through the ages
2013-09-25
An international team of archaeologists led by experts from the University of York has uncovered evidence of human activity in the high slopes of the French Alps dating back over 8000 years.
The 14-year study in the Parc National des Eìcrins in the southern Alps is one of the most detailed archaeological investigations carried out at high altitudes. It reveals a story of human occupation and activity in one of the world's most challenging environments from the Mesolithic to the Post-Medieval period.
The work included the excavation of a series of stone animal enclosures ...
Discovery offers bio-solution to severe canola crop losses
2013-09-25
A genetic discovery by a University of Calgary-led international research team offers a solution to a long-standing "green seed problem" that causes millions of dollars annually in canola crop losses.
Led by Marcus Samuel in the Faculty of Science, researchers from the U of C, the University of Toronto and the University of Bordeaux in France, have uncovered a plant gene regulatory network that could be genetically enhanced to prevent green seeds from occurring in mature canola.
"The annual loss in North America alone is close to $150 million from this de-greening issue," ...
Dams provide resilience to Columbia River basin from climate change impacts
2013-09-25
CORVALLIS, Ore. – Dams have been vilified for detrimental effects to water quality and fish passage, but a new study suggests that these structures provide "ecological and engineering resilience" to climate change in the Columbia River basin.
The study, which was published in the Canadian journal Atmosphere-Ocean, looked at the effects of climate warming on stream flow in the headwaters and downstream reaches of seven sub-basins of the Columbia River from 1950 to 2010. The researchers found that the peak of the annual snowmelt runoff has shifted to a few days earlier, ...
Some childhood cancer survivors may face subsequent renal problems
2013-09-25
PHILADELPHIA -- Adult survivors of childhood cancers who underwent certain chemotherapy treatments or kidney surgery had worse kidney function that did not recover over time. Because of this, they may be at higher risk for premature renal failure, according to a study published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.
"Current knowledge suggests childhood cancer survivors (CCS) have an increased risk for impaired kidney function after specific cancer therapies; however, it was not known whether their kidney ...
Diet and exercise for knee osteoarthritis produces greater improvement in knee pain, function
2013-09-25
Among overweight and obese adults with knee osteoarthritis, combining intensive diet and exercise led to less knee pain and better function after 18 months than diet-alone and exercise-alone, according to a study in the September 25 issue of JAMA.
"Osteoarthritis (OA) is the leading cause of chronic disability among older adults. Knee OA is the most frequent cause of mobility dependency and diminished quality of life, and obesity is a major risk factor for knee OA. Current treatments for knee OA are inadequate; of patients treated pharmacologically, only about half experience ...
Study findings question frequency of bone mineral density testing for predicting fracture risk
2013-09-25
A second bone mineral density (BMD) screening four years after a baseline measurement provided little additional value when assessing risk for hip or other major osteoporotic fracture among older men and women untreated for osteoporosis, and resulted in little change in risk classification used in clinical management, findings that question the common clinical practice of repeating a BMD test every 2 years, according to a study in the September 25 issue of JAMA.
Bone mineral density testing is important in the management of osteoporosis. Guidelines for initiating pharmacologic ...
Sensor-augmented insulin pump therapy reduces rate of severe hypoglycemic events
2013-09-25
Use of an insulin pump with a sensor that suspends insulin delivery when blood glucose falls below a set threshold reduced the rate of severe and moderate hypoglycemia among patients with type 1 diabetes and impaired awareness of hypoglycemia, according to a study in the September 25 issue of JAMA.
Hypoglycemia is a critical obstacle to the care of patients with type 1 diabetes. Sensor-augmented pump therapy with an automated insulin suspension or low glucose suspension function is a technology has the potential to reduce the duration and frequency of significant hypoglycemia, ...
Decision-making tool may help rule out brain hemorrhage for patients in emergency department
2013-09-25
Researchers have developed a simple clinical decision rule that may help doctors identify patients with headache in the emergency department who have subarachnoid hemorrhage (bleeding in a certain area of the brain), according to a study in the September 25 issue of JAMA.
"Headache accounts for approximately 2 percent of all emergency department visits, and subarachnoid hemorrhage is one of the most serious diagnoses, accounting for only 1 percent to 3 percent of these headaches. Although the decision to evaluate patients with new neurologic deficits is relatively straightforward, ...