Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Bacteria live in the esophagus!


The esophagus isn’t merely a tube for food traveling from the mouth to the stomach, it also provides an environment for bacteria to live, according to a new study by NYU School of Medicine scientists that overturns the general belief that the esophagus is free of bacteria.

"People thought that the esophagus wasn’t hospitable to bacteria," says Martin J. Blaser, M.D., Frederick King Professor and Chairman of the Department of Medicine, and Professor of Microbiology, an author of the study. Bacteria were believed to move through the esophagus, the tube connecting the mouth to the stomach, as food-borne passengers on route to the stomach.

But the new study in the March 23 print issue of the Proceedings of the National Academy of Sciences demonstrates that bacteria do indeed live in the esophagus, and these microbes are a diverse bunch. "This study provides evidence for the first time that there are indigenous microbes in the human esophagus," says Zhiheng Pei, M.D., Ph.D., Assistant Professor of Pathology and Medicine, the study’s lead author.

The findings may have profound implications for treating diseases of the esophagus, including gastroesophageal reflux disease (GERD), which afflicts some 10 million people in the United States. Chronic inflammation associated with GERD can lead to the development of a precancerous condition called Barrett’s esophagus. If disease-causing bacteria are ever found in the esophagus, it may one day be possible to treat these diseases with antibiotics.

While bacteria in the esophagus will be news to most people, the NYU researchers had suspected that the food tube harbored microorganisms. After all, bacteria have now been found in deep-sea vents, hot springs, volcanoes, and other extremely harsh environments. "By comparison, the esophagus seemed much more hospitable," says Dr. Blaser.

In human biology, too, there have been surprises concerning bacteria. For many years, doctors didn’t believe that bacteria could survive in the acid environment of the stomach. But in the early 1980s, researchers discovered that the bacterium Helicobacter pylori lived in the stomach and is associated with ulcers. Antibiotics are now routinely used to treat ulcers. In subsequent years, Dr. Blaser and other scientists established the bacterium’s link to certain kinds of stomach cancers.

The connection between H. pylori and gastric cancer was one of the reasons why the NYU researchers were drawn to the esophagus. Might certain kinds of disease-causing bacteria also reside in the esophagus? While bacteria have long been known to inhabit the mouth, the evidence that bacteria even lived in the esophagus was inconclusive. Previous studies of the esophagus didn’t consistently find bacteria in the esophagus that could be cultured. Textbooks have never described microbes in the esophagus.

Rather than relying on the conventional methods of culturing bacteria in petri dishes in the laboratory, the researchers decided to mine DNA libraries that have been compiled of bacterial genes. They used a technique called PCR (polymerase chain reaction) to greatly amplify snippets of DNA extracted from biopsies of tissue from the esophagus, and they compared the sequences of the DNA in the biopsies to known bacterial DNA.

The biopsies were taken from four patients who each had a healthy esophagus. Specifically, the biopsies were taken from the distal esophagus, the part closest to the stomach. This area is especially vulnerable to injury due to the backwash of gastric contents that occurs as a consequence of GERD.

The researchers found 95 species of bacteria, and they estimated that they were able to sample 56 to 79 percent of the species in the biopsies. Therefore, even more species may be present. Many of these bacteria resemble garden-variety microorganisms that aren’t known to cause disease.

More than 60 percent of the esophageal bacteria were shared among all four individuals, indicating that populations of certain bacterial species appear to be common to all people, according to the study. Although many of the bacteria in the esophagus were highly related to the bacteria found in the mouth, certain bacteria were not known residents of the mouth, says Dr. Pei. This finding suggests that some, if not all, "esophageal bacteria may be unique," he notes.

Importantly, Dr. Pei also directly viewed bacteria colonizing the surface of the esophagus, proving that the bacteria weren’t simply traveling through the tube but had taken up residence in the tissue lining it.

Esophageal adenocarcinoma, a kind of cancer, has been increasing rapidly in white men, according to the National Cancer Institute, which sponsored the NYU study. "Animal studies suggest that inflammation and normal bacteria work in concert to cause colon cancer," says Dr. Pei. "Esophageal cancer arises in an area of the esophagus where chronic inflammation is occurring," notes Dr. Pei.

In the next phase of their work, the researchers plan to identify the bacteria in the esophagus in people who have GERD and other esophageal conditions. They suspect that they may find different bacteria in the samples of unhealthy esophageal tissue, which could suggest that microorganisms are playing a role.

"We are operating in the framework of the ’microbiome’, a term coined by Nobel Laureate Joshua Lederberg," says Dr. Blaser. "It means that microbes are part of us, part of our identity. They aren’t just passengers," he says, " but are, in essence, metabolic and physiologic compartments of the human body."

Pamela McDonnell | EurekAlert!
Further information:

More articles from Health and Medicine:

nachricht Advanced analysis of brain structure shape may track progression to Alzheimer's disease
26.10.2016 | Massachusetts General Hospital

nachricht Indian roadside refuse fires produce toxic rainbow
26.10.2016 | Duke University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel light sources made of 2D materials

Physicists from the University of Würzburg have designed a light source that emits photon pairs. Two-photon sources are particularly well suited for tap-proof data encryption. The experiment's key ingredients: a semiconductor crystal and some sticky tape.

So-called monolayers are at the heart of the research activities. These "super materials" (as the prestigious science magazine "Nature" puts it) have been...

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Prototype device for measuring graphene-based electromagnetic radiation created

28.10.2016 | Power and Electrical Engineering

Gamma ray camera offers new view on ultra-high energy electrons in plasma

28.10.2016 | Physics and Astronomy

When fat cells change their colour

28.10.2016 | Life Sciences

More VideoLinks >>>