MICROBIOME AND GERM-FREE INSIGHTS


Ensuring Sterile Feed for Germ-Free Mice

With the increase in institutions that are initiating microbiome studies comes an increase in demands for sterile support materials. Setting up and maintaining isolators to breed and perform studies with germ-free mice is a challenge. There are a number of ways that a biological contaminant can enter an isolator, but the highest risk of contamination may be from improperly sterilized feed. To help us understand better how...

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WHAT IS THE MICROBIOME?

The microbiome is the collection of microorganisms living in and on an organism, such as a human or mouse. Interest in the microbiome is increasing due to a clearer understanding of the its impact on a number of different physiological systems, as well as the realization that microbial communities can vary widely from person-to-person. Aleksandar D. Kostic et al. Genes Dev. 2013; 27:701-718. Copyright© 2013 by Cold...

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Do Some IBD Treatments Work by Altering the Gut Microbiota?

An IBD treatment targeting key cytokine components appears to alter the microbiome in mouse models of IBD. What's the connection? Cytokines have been implicated in the pathogenesis of inflammatory bowel diseases such as Crohn's disease and ulcerative colitis, and modulation of cytokines is one therapeutic strategy. Ustekinumab, an antibody that targets IL-12p40 and a component of the cytokines IL-12 and IL-23, demonstrated clinical efficacy against Crohn's disease,...

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Does the Microbiome Affect Behavior in Germ-free Mice?

There is growing evidence that the microbiome, that collection of all the microorganisms which inhabit an individual, can affect cognition and behavior. This has been termed the microbiota-gut-brain axis. Germ-free mice are a critical tool in studies investigating this connection, and they have been shown to have alterations in behavior and cognition compared to conventional mice. Desbonnet et al. demonstrated that germ-free Swiss Webster mice exhibited social...

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Activated Soy Affects Weight Gain and Microbiome in Obese Mice

Researchers from the USDA, Tulane, LSU, and Microbiome Therapeutics have linked soy pod fiber to significantly reduced weight gain in obese mice. (Source: Obesity. 2016 Jan;24(1):87-95.) The study looked at activated soy pod fiber as a dietary intervention in mice fed an obesogenic diet. Two groups of male C57BL/6NTac mice were fed a purified diet similar to the "condensed milk" diet, with one group's diet altered to...

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Choosing a Health Standard for Your Model

Taconic produces rodent models at several different health standards. How do you know which health designation to choose when ordering animals? Taconic rodent models are available at multiple health standards, enabling researchers to choose the most appropriate model for their studies. These five health standards are defined by the progressive exclusion of foreign organisms. The general health standard for most immunocompetent models is Murine Pathogen Free™ (MPF™)....

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Production of Germ-Free Mice: Then and Now

On September 26, 1949, Life Magazine showed the world "a strange, new sterile laboratory at Notre Dame", where animal care technicians in diving suits submerged themselves in germicidal tanks, and animals were raised in sealed environments. Scientists were curious whether germ-free organisms would live longer, and planned to study cancer, heart disease, tooth decay, and more. That first germ-free laboratory was a marvel, but it was beyond...

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Where You Source Your Lab Mice Matters

Has a study ever performed as expected the first time you run it, but the results stop making sense in subsequent trials? You used the same strain of mice, same sex and same age. The only variable appears to be the vendor...what could be happening? In a previous Insight, I discussed considerations for mouse breeding. One of the suggestions in that post was that it may be...

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Should Your Fecal Microbiota Transplantation Study Use Germ-Free Mice?

Are you planning on doing some fecal microbiota transplant studies? Unsure whether to use germ-free or antibiotic treated mice for your studies? In a recent review paper (Gut Microbes, March 2016), Randi Lundberg and her coauthors present the pros and cons for using antibiotic-treated or germ-free mice in fecal microbiota transplant (FMT) studies. Neither model truly represents physiological nor immunological conditions found in SPF mice, but can...

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8 Best Practice Resources for Working with Germ-Free Mice

The volume of published studies employing axenic or germ-free mice increased dramatically over the past 15 years, in part due to growing interest in microbiome research. As germ-free mouse model studies gain relevance, so does the importance of establishing best practices while researchers start and maintain research colonies. Today, we'll address eight of the most frequently-asked questions regarding axenic mouse colony best practices. It is generally accepted...

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