Showing category "Microbiota" (Show all posts)

Probiotic puzzle

Posted by Heather Maughan on Tuesday, December 4, 2012, In : Microbiota 
Probiotics are live bacteria, formulas of single or multiple species, provided to help establish a healthy gastrointestinal tract.  Probiotics are a hot topic these days, and a potent marketing tool. Despite their popularity, we often don't know if they really work to relieve intestinal problems.  And for those probiotics that do work, we almost never know their mechanism(s) of action.   

Olier and colleagues have taken us a step closer to understanding the mechanism of probiotic action.  They...

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Bacterial relocation II

Posted by Heather Maughan on Monday, November 26, 2012, In : Microbiota 
Continuing on the subject of bacteriotherapy, there was a fascinating paper out last month in PLoS Pathogens by Lawley et al. As I said in the last post, C. difficile infection of the gut is bad news, and one of the best cures is fecal transplantation.  Lawley et al. describe experiments in a mouse model that closely approximates the situation in humans.  They showed that the epidemic strain of C. difficile 027/BI is much more of a terror than other strains, as the bug was highly contagious a...
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Bacterial relocation

Posted by Heather Maughan on Sunday, November 4, 2012, In : Microbiota 
Warning: Here comes the icky diarrhea blog.  Because I primarily write about microbiota, this was only a matter of time as the literature is replete with gut microbiota studies.  This abundance is due to lots of money being poured into figuring out the role of the gut microbiota; they are likely to influence a plethora of diseases through their role in immune system development, and fecal samples are easy to obtain!

Fecal samples are also relatively easy to transplant.  This may sound gross be...
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Phages as fighters

Posted by Heather Maughan on Tuesday, October 16, 2012, In : Microbiota 

 
Not all ingested bacteria will be able to colonize the intestines upon arrival.  Some bacteria may not be adapted to living in the GI tract, and are merely passersby waiting to be ejected into the environment to find their favored niche.  Other bacteria are happy to be in the GI tract where nutrients are abundant, but must contend with the other hungry microbes and the vigilant immune system.  When competition is fierce, a particular bacterial species may “win” by producing toxins that k...

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Microbial seeds

Posted by Heather Maughan on Tuesday, September 11, 2012, In : Microbiota 

People with the genetic disease Cystic Fibrosis suffer from decreased lung and pancreatic functions, the former of which is often attributed to the thickened lung mucous that prevents expulsion of inhaled bacteria.  Many research groups are using DNA sequencing methods to characterize the communities of bacteria that live in CF lungs, and a smaller number of research groups have addressed the issue of intestinal bacterial communities that could be affected ...


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Cryptic habitat

Posted by Heather Maughan on Tuesday, July 3, 2012, In : Microbiota 
Imagine mixing all living animals in North America up in a (very large) bag, identifying which species are in the mix, and then making educated guesses about how those animals live.  Do the fishes and birds share a niche?  How often do monarch butterflies and polar bears interact?  We know the answers to these questions are dependent on the North American habitat in which each animal lives.  Sometimes fishes and birds do interact, but only in particular habitats. 

This mental exercise may see...
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