Scientists Discover Natural Antibiotic in Human Gut
January 27, 2003 03:18:40 PM PST,Researchers have found a potent antibacterial protein that is made naturally by the human body.The protein, dubbed Ang4, is created by cells in the intestines, according to a study published in the advance online version of the journal Nature Immunology.
It is likely that Ang4 normally plays a role in protecting the lining of the intestines, the study's lead author, Lora V. Hooper, explained in an interview with Reuters Health.
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"We showed that Ang4 kills many different types of gut bacteria," said Hooper, a researcher at Washington University School of Medicine in St. Louis, Missouri. "We think that Ang4 is part of the arsenal that use to keep bacteria from getting too close to the intestinal lining and causing damage."
Hooper and her colleagues also found that Ang4 was a potent killer of a type of bacteria called listeria monocytogenes, which has been implicated in recent cases of severe food poisoning.Interestingly, Hooper pointed out, bacteria that normally live in the gut control the release of Ang4.
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There are numerous types of bacteria that live in the intestines in a kind of healthy, symbiotic relationship with their human hosts, explained study co-author Dr. Jeffrey I. Gordon, a professor and head of the department of molecular biology and pharmacology at the Washington University School of Medicine.Without these bacteria, human beings would not be able to digest certain types of plant-derived nutrients, Gordon said. The breakdown of these nutrients is "assigned to our microbial partners," he added. "Their genes are the ones that have the encoding for the enzymes necessary for breaking down these important nutrients."
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But even these "friendly" bacteria can do damage to the gut if they spread too deeply into the intestinal lining, Hooper explained. If they spread into the lining, the body will respond with inflammation, eventually killing off all the bacteria.
So, a system for protecting the intestinal lining has evolved over time, Hooper said. By signaling certain cells in the intestines to release Ang4, the bacteria keep their own numbers in check, creating a sort of "protective electric fence" around the intestinal lining.
, 百拇医药
"By controlling the expression of these types of antibiotic proteins, the bacteria are helping to shape their own neighborhood," Gordon said. "They groom the landscape in ways that are beneficial for both the host and the bug."
Ultimately, Gordon said, research into how Ang4 and other naturally occurring antibiotics work may lead to better medicines.
"Understanding the mechanism of how these proteins kill bacteria may lead to a better understanding of the chinks in the bacteria's armor," he added. "With the tremendous amount of resistant bacteria out there, it's important to push the envelope to find new classes of antibiotics-new tools to fight bacterial infections."
Source: Nature Immunology online edition 2003;10.1038/ni888., 百拇医药
It is likely that Ang4 normally plays a role in protecting the lining of the intestines, the study's lead author, Lora V. Hooper, explained in an interview with Reuters Health.
, 百拇医药
"We showed that Ang4 kills many different types of gut bacteria," said Hooper, a researcher at Washington University School of Medicine in St. Louis, Missouri. "We think that Ang4 is part of the arsenal that use to keep bacteria from getting too close to the intestinal lining and causing damage."
Hooper and her colleagues also found that Ang4 was a potent killer of a type of bacteria called listeria monocytogenes, which has been implicated in recent cases of severe food poisoning.Interestingly, Hooper pointed out, bacteria that normally live in the gut control the release of Ang4.
, 百拇医药
There are numerous types of bacteria that live in the intestines in a kind of healthy, symbiotic relationship with their human hosts, explained study co-author Dr. Jeffrey I. Gordon, a professor and head of the department of molecular biology and pharmacology at the Washington University School of Medicine.Without these bacteria, human beings would not be able to digest certain types of plant-derived nutrients, Gordon said. The breakdown of these nutrients is "assigned to our microbial partners," he added. "Their genes are the ones that have the encoding for the enzymes necessary for breaking down these important nutrients."
, http://www.100md.com
But even these "friendly" bacteria can do damage to the gut if they spread too deeply into the intestinal lining, Hooper explained. If they spread into the lining, the body will respond with inflammation, eventually killing off all the bacteria.
So, a system for protecting the intestinal lining has evolved over time, Hooper said. By signaling certain cells in the intestines to release Ang4, the bacteria keep their own numbers in check, creating a sort of "protective electric fence" around the intestinal lining.
, 百拇医药
"By controlling the expression of these types of antibiotic proteins, the bacteria are helping to shape their own neighborhood," Gordon said. "They groom the landscape in ways that are beneficial for both the host and the bug."
Ultimately, Gordon said, research into how Ang4 and other naturally occurring antibiotics work may lead to better medicines.
"Understanding the mechanism of how these proteins kill bacteria may lead to a better understanding of the chinks in the bacteria's armor," he added. "With the tremendous amount of resistant bacteria out there, it's important to push the envelope to find new classes of antibiotics-new tools to fight bacterial infections."
Source: Nature Immunology online edition 2003;10.1038/ni888., 百拇医药