A new study by NYU School of Medicine researchers reveals that an especially virulent strain of the gut bacterium Helicobacter pylori (H. pylori) isn't implicated in the overall death rate of the U.S. population, and may even protect against stroke and some cancers. The findings, based a nationwide health survey of nearly 10,000 individuals over a period of some 12 years, are published online, January 9, in the journal Gut.
Those individuals carrying the most virulent strain of H. pylori, the study found, had a 55 percent reduced risk of deaths from stroke compared with their counterparts who were not infected with H. pylori. Participants with the most virulent strain also had a 45 percent reduced risk of death from lung cancer.
These surprising findings emerged from an analysis by Yu Chen, PhD, MPH, associate professor of population health and environmental medicine, and Martin J. Blaser, MD, professor of internal medicine and professor of microbiology, of individuals who participated in a national survey designed to assess the health and nutritional status of adults and children in the United States. Previous studies by Dr. Blaser have confirmed the bacterium's link to gastric diseases ranging from gastritis to stomach cancer. He and Dr. Chen have more recently shown that H. pylori may protect against childhood asthma. The most virulent H. pylori strains have a gene called cagA.
"The significance of this study is that this is a prospective cohort of participants representative of the U.S. population with a long follow-up," says Dr. Chen. "We studied both the overall H. pylori as well as cagA strain of H. pylori, which is more interactive with the human body. We found that H. pylori is not related to the risk of death from all causes, despite it being related to increased risk of death from gastric cancer."
"This finding confirms earlier work, however, that gastric cancers are now uncommon in the United States," says Dr. Chen. "We also found that H. pylori was related to a reduced risk of stroke and lung cancer, and these effects were stronger for the cagA strain, suggesting its mixed role in human health," she says.
H. pylori, an ancient bacterium, lives in the mucous layer lining the stomach where, until recently, it survived for decades. More than half of the world's population harbor H. pylori in their upper gastrointestinal tract. Mainly transmitted in families, the bacterium is usually acquired before age 10. In developing countries H. pylori is still prevalent, but is vanishing in the developed world thanks to better sanitation and widespread use of antibiotics.
To better understand the relationship between H. pylori and the overall death rate, or all-cause mortality, the researchers analyzed data from 9,895 participants in the National Health and Nutrition Surveys (NHANES III), enrolled from 1988 to 1994. Test results for H. pylori and cagA were available on 7,384 subjects at the time of enrollment, and participants were followed until 2000.
There was no association of either H. pylori-positivity or cagA-positivity with all-cause mortality in the population, the researchers found. Participants with and without H. pylori experienced a similar risk of death from all causes. Consistent with past reports, a strong association was observed between H. pylori and gastric cancer mortality, according to the study. Individuals who were H. pylori positive were 40 times more likely to die from gastric cancer. The study also found that participants with cagA-positivity had a 55 percent reduced risk of deaths from stroke compared with their counterparts who were H. pylori negative/ cagA-negative. Participants with cagA-positivity also had a 45 percent reduced risk of deaths from lung cancer.
"The most interesting finding was that there is a strong inverse association with stroke which could be protective," says Dr. Blaser. "There is some precedent for this and it is possible that the same cells (T reg cells) that H. pylori induces that protect against childhood asthma could be the protective agents, however, the findings need to be confirmed."
Authors: Yu Chen. PhD, MPH, associate professor, Departments of Population Health and Environmental Medicine; Stephanie Segers, MPH, statistician, Department of Population Health; Martin J. Blaser, MD, professor, Departments of Medicine and Microbiology.
Competing Interests: None reported.
Funding/Support: This work was supported in part by grants R01DK090989, R01GM63270, ES000260, and P30CA16087 from the National Institutes of Health, and by the Diane Belfer Program for Human Microbial Ecology.
About NYU School of Medicine:
NYU Langone Medical Center, a world-class, patient-centered, integrated, academic medical center, is one on the nation's premier centers for excellence in clinical care, biomedical research and medical education. Located in the heart of Manhattan, NYU Langone is composed of three hospitals – Tisch Hospital, its flagship acute care facility; the Rusk Institute of Rehabilitation Medicine, the world's first university-affiliated facility devoted entirely to rehabilitation medicine; and the Hospital for Joint Diseases, one of only five hospitals in the nation dedicated to orthopaedics and rheumatology – plus the NYU School of Medicine, which since 1841 has trained thousands of physicians and scientists who have helped to shape the course of medical history. The medical center's tri-fold mission to serve, teach and discover is achieved 365 days a year through the seamless integration of a culture devoted to excellence in patient care, education and research.
Lorinda Klein | EurekAlert!
The world's tiniest first responders
21.06.2018 | University of Southern California
A new toxin in Cholera bacteria discovered by scientists in Umeå
21.06.2018 | Schwedischer Forschungsrat - The Swedish Research Council
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
21.06.2018 | Earth Sciences
21.06.2018 | Life Sciences
21.06.2018 | Earth Sciences