my.bionity.com
With an accout for my.bionity.com you can always see everything at a glance – and you can configure your own website and individual newsletter.
26-06-2012: The human gut is home to a teeming ecosystem of microbes that is intimately involved in both human health and disease. But while the gut microbiota is interacting with our body, they are also under constant attack from viruses. In a study published in Genome Research, researchers have analyzed a bacterial immune system, revealing a common set of viruses associated with gut microbiota in global populations.
Viruses that prey on bacteria, called phages, pose a constant threat to the health of bacterial communities. In many ecological systems, viruses outnumber bacterial cells ten to one. Given the richness of bacteria in the human gut, it was not surprising that scientists have found that phages are also highly prevalent. But how can viruses targeting gut microbiota be identified? How do viral communities differ between people and global populations, and what could this tell us about human health and disease?
In this report, a team of scientists from Israel has taken advantage of information coded in a bacterial immune system to shed new light on these questions. Bacteria can “steal” small pieces of DNA from phages that attack them, and use these stolen pieces to recognize and respond to the attacker, in a manner similar to usage of antibodies by the human immune system. The stolen DNA pieces are stored in specific places in the bacterial genome called CRISPR loci (clustered regularly interspaced short palindromic repeats).
“In our study we searched for such stolen phage DNA pieces carried by bacteria living in the human gut,” said Rotem Sorek of the Weizmann Institute of Science and senior author of the study. “We then used these pieces to identify DNA of phages that co-exist with the bacteria in the gut.”
Sorek’s team used this strategy to identify and analyze phages present in the gut microbiota of a cohort of European individuals. They found that nearly 80% of the phages are shared between two or more individuals. The team compared their data to samples previously derived from American and Japanese individuals, finding phages from their European data set also present in these geographically distant populations, a surprising result given the diversity of phages seen in other ecological niches.
Sorek explained that their findings mean that there are hundreds of types of viruses that repeatedly infect our gut microbiota. “These viruses can kill some of our gut bacteria,” said Sorek. “It is therefore likely that these viruses can influence human health.”
The authors note that as evidence for the beneficial roles played by bacteria in the healthy human gut continues to mount, it is critical that we understand the pressures placed upon the “good” bacteria that are vital to human health. “Our discovery of a large set of phages attacking these good bacteria in our gut opens a window for understanding how they affect human health,” Sorek added. Researchers can now begin to ask how phage dynamics in the gut changes over time, and what it might tell us about diseases, such as inflammatory bowel disease, and how to more effectively treat them.
Original publication:
Stern A, Mick E, Tirosh I, Sagy O, Sorek R.; "CRISPR targeting reveals a reservoir of common phages associated with the human gut microbiome."; Genome Res
Contact / Request information
Request further information free of charge:
Watchlist
This is where you can add this news to your personal favourites
In the bacterial world of your mouth, nurture wins out over nature
The human mouth is home to a teeming community of microbes, yet still relatively little is known about what determines the specific types of microorganisms that live there. Is it your genes that decide who lives in the microbial village, or is it your environment? In a study published in ... more
Differences between human twins at birth highlight importance of intrauterine environment
Your genes determine much about you, but environment can have a strong influence on your genes even before birth, with consequences that can last a lifetime. In a study published in Genome Research, researchers have for the first time shown that the environment experienced in the womb defi ... more
Gut microbes battle a common set of viruses shared by global populations
The human gut is home to a teeming ecosystem of microbes that is intimately involved in both human health and disease. But while the gut microbiota is interacting with our body, they are also under constant attack from viruses. In a study published in Genome Research, researchers have ana ... more
We investigated the role of cholinergic neurotransmission in olfactory fear learning. Mice receiving pairings of odor and foot shock displayed fear to the trained odor the following day. Pretraining injections of the nicotinic antagonist mecamylamine had no effect on subsequent freezing, w ... more
In Aplysia, repeated trials of aversive stimuli produce long-term sensitization (LTS) of defensive reflexes and suppression of feeding. Whereas the cellular underpinnings of LTS have been characterized, the mechanisms of feeding suppression remained unknown. Here, we report that LTS traini ... more
The anaphase promoting complex/cyclosome (APC/C) is an E3 ligase regulated by Cdh1. Beyond its role in controlling cell cycle progression, APC/C–Cdh1 has been detected in neurons and plays a role in long-lasting synaptic plasticity and long-term memory. Herein, we further examined the role ... more
Tokyo Institute of Technology research: Towards medical treatments using cell level control
Researchers at Tokyo Institute of Technology and the Weizmann Institute of Science identify a means of controlling biological processes that could help treatments for immune disease, neurological disorders and cancer.The cellular response to a number of signals including inflammatory cytoki ... more
Gut microbes battle a common set of viruses shared by global populations
The human gut is home to a teeming ecosystem of microbes that is intimately involved in both human health and disease. But while the gut microbiota is interacting with our body, they are also under constant attack from viruses. In a study published in Genome Research, researchers have ana ... more
How cells brace themselves for starvation
Sugar, cholesterol, phosphates, zinc – a healthy body is amazingly good at keeping such vital nutrients at appropriate levels within its cells. From an engineering point of view, one all-purpose model of pump on the surface of a cell should suffice to keep these levels constant: When the co ... more
The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,700 scientists, students, technicians and supporting staff. I ... more
Individual protein complex generates electric current
An team of scientists, led by Joachim Reichert, Johannes Barth, and Alexander Holleitner (Technische Universitaet Muenchen, Clusters of Excellence MAP and NIM), and Itai Carmeli (Tel Aviv University) developed a method to measure photocurrents of a single functionalized photosynthetic prote ... more
Viruses could be the key to healthy corals
Corals are an invaluable part of the marine ecosystem, fostering biodiversity and protecting coastlines. But they're also increasingly endangered. Pathogenic bacteria, along with pollution and harmful fishing practices, are one of the biggest threats to the world's coral populations today.O ... more
While your DNA is unique, it also tells the tale of your family line. It carries the genetic history of your ancestors down through the generations. Now, says a Tel Aviv University researcher, it's also possible to use it as a map to your family's past.Prof. Eran Halperin of TAU's Blavatnik ... more
Über CHEMIE.DE
CHEMIE.DE Information Service GmbH runs specialist scientific internet portals. The secret to our success? We are familiar with what we publish.
Advertising at CHEMIE.DE
Our advertising formats support you in getting your message across to a clearly defined target audience.
© 1997-2013 CHEMIE.DE Information Service GmbH, All rights reserved
Netmeeting
