Health and Medical News and Resources

General interest items edited by Janice Flahiff

[News article] The microbiome and the midnight snack: How gut microbes influence the body’s clock

From the 13 May 2015 Science Life article

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Poor sleep has long been linked with changes to the metabolism. Disruption of the body’s internal clock can lead to changes in appetite and cravings for unhealthy food, which in turn leads to more serious health problems like obesity, diabetes and heart disease.

New research from the University of Chicago highlights a third component to that cycle: the millions of microbes that live in the intestines. These organisms respond to the same environmental cues as their host organism; their activity and metabolism is intertwined with the sleep/wake cycles and feeding schedules of the animal.

May 20, 2015 Posted by | Nutrition | , , , , | Leave a comment

[Press release] Among gut microbes, strains, not just species, matter

From the 29 January 2015 University of Washington press release

First large-scale analysis completed of intra-species genetic variation in gut’s resident organisms

By Leila Gray  |  HSNewsBeat  |  Updated 9:00 AM, 01.29.2015

Posted in: Research

  • Gut microbiomes from different people can contain similar microbial species, but different strains, as this cartoon illustrates.Dana C, Thomas

A large community of microorganisms calls the human digestive tract home.  This dynamic conglomerate of microscopic life forms – the gut microbiome – is vital to how people metabolize various nutrients in their food, how their immune systems react to infection, and how they respond to various medications.  Moreover, imbalances in the microbiome are thought to play a significant role in many human diseases.

The collection of species occupying the gut is known to be quite personalized, and people may differ considerably in the set of species they harbor. Now new research suggests that the differences between people may go even deeper. In a paper published Jan. 29 in Cell, researchers at the University of Washington show that even when people share microbes in common, the exact strains each carries might be very different.

“Knowing more about these strain-level variations,” said Elhanan Borenstein, the senior author of this paper and an associate professor of genome sciences at the University of Washington, “is crucial for understanding the complex relationship between the composition of the community of microbes living in the human gut and its influence on health and disease.”

January 30, 2015 Posted by | Medical and Health Research News | , , , , , , , , , , | Leave a comment

[Magazine article] Sorry, Your Gut Bacteria Are Not the Answer to All Your Health Problems | Mother Jones

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Sorry, Your Gut Bacteria Are Not the Answer to All Your Health Problems | Mother Jones.

Excerpts

In 2001, Joshua Lederberg, a Nobel Prize-winning biologist, coined the term “microbiome,” naming the trillions of microorganisms that reside in and on our bodies. Today, if you type that word into Google, you’ll turn up thousands of hits linking gut bacteria to a laundry list of health problems, from food allergies to Ebola. Between 2007 and 2012, the number of journal articles published on the microbiome increased by nearly 250 percent. Our bodily inhabitants are quickly being cast as culprits or saviors for a diverse array of ailments.

Still, despite the optimism, some researchers caution that much of what we hear about microbiome science isn’t always, well, science. Dr. Lita Proctor heads the National Institutes of Health (NIH) Human Microbiome Project (HMP), an outgrowth of the Human Genome Project. “We are discovering a whole new ecosystem,” she says. But “I do have some fear—we all do in the field—that the hype and the potential overpromise, and the idea that somehow this is going to be different—there is a terrific fear that it will all backfire.”

he goal of the first phase of the HMP was to identify the microbial makeup of a “healthy” microbiome. And, in a study published earlier this year, researchers made an important discovery—that there is no such thing. Even among people who were examined and found to be perfectly healthy, each person’s microbiome was unique.

“We were going about it all wrong,” Proctor explains. “It is not the makeup—these communities come together and they actually become bigger than the sum of their parts…It almost doesn’t matter who is present, it just matters what they are doing.”

Jonathan Eisen, a professor and biologist who studies the ecology of microbes at the University of California-Davis, shares Proctor’s concerns. In a series on his blog called “The Overselling the Microbiome Awards,” Eisen highlights what he considers to be skewed science. He has taken on transplants purported to treat multiple sclerosis, celiac disease, and Crohn’s disease. He casts doubt on a study claiming there’s a connection between a mother’s oral hygiene during pregnancy to the health of her newborn. He critiques the notion that you can use bacteria to battle breast cancer, prevent stroke, and cure Alzheimer’s.

Eisen says that one of the most common errors in studies is confusion between correlation and causation. [My emphasis!]  “The microbiome has 400 million different variables that you can measure about it,” Eisen explains. “The different sites, the different species, the relative abundance of those species, the variation—if you have that many variables, I can guarantee statistically that some of them will be perfectly correlated with Crohn’s disease and have nothing to do with it.”

November 4, 2014 Posted by | Consumer Health, Medical and Health Research News | , , , , | Leave a comment

BBC – Future – Body bacteria: Can your gut bugs make you smarter?

BBC – Future – Body bacteria: Can your gut bugs make you smarter?.

Excerpts from the 21 February 2014 article

The bacteria in our guts can influence the working of the mind, says Frank Swain. So could they be upgraded to enhance brainpower?

I have some startling news: you are not human. At least, by some counts. While you are indeed made up of billions of human cells working in remarkable concert, these are easily outnumbered by the bacterial cells that live on and in you – your microbiome. There are ten of them for every one of your own cells, and they add an extra two kilograms (4.4lbs) to your body.

Far from being freeloading passengers, many of these microbes actively help digest food and prevent infection. And now evidence is emerging that these tiny organisms may also have a profound impact on the brain too. They are a living augmentation of your body – and like any enhancement, this means they could, in principle, be upgraded. So, could you hack your microbiome to make yourself healthier, happier, and smarter too?

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“Diet is perhaps the biggest factor in shaping the composition of the microbiome,” he says. A study by University College Cork researcherspublished in Nature in 2012 followed 200 elderly people over the course of two years, as they transitioned into different environments such as nursing homes. The researchers found that their subjects’ health – frailty, cognition, and immune system – all correlated with their microbiome. From bacterial population alone, researchers could tell if a patient was a long-stay patient in a nursing home, or short-stay, or living in the general community. These changes were a direct reflection of their diet in these different environments. “A diverse diet gives you a diverse microbiome that gives you a better health outcome,” says Cryan.

Beyond a healthy and varied diet, though, it still remains to be discovered whether certain food combinations could alter the microbiome to produce a cognitive boost. In fact, Cryan recommends that claims from probiotic supplements of brain-boosting ought to be taken with a pinch of salt for now. “Unless the studies have been done, one can assume they’re not going to have any effect on mental health,” he says. Still, he’s optimistic about the future. “The field right now is evolving very strongly and quickly. There’s a lot of important research to be done. It’s still early days.”

 

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March 13, 2014 Posted by | Medical and Health Research News, Nutrition, Psychology | , , , , , , , | Leave a comment

Microbes can influence evolution of their hosts

From the 18 July 2013 article at EurkAlert

Microbes can influence evolution of their hosts

New evidence supporting the hologenome theory of evolution

 IMAGE: This is an illustration of the tree of life created in microbial culture.

Click here for more information. 

You are not just yourself. You are also the thousands of microbes that you carry. In fact, they represent an invisible majority that may be more you than you realize.

These microscopic fellow travelers are collectively called the microbiome. Realization that every species of plant and animal is accompanied by a distinctive microbiome is old news. But evidence of the impact that these microbes have on their hosts continues to grow rapidly in areas ranging from brain development to digestion to defense against infection to producing bodily odors.

Now, contrary to current scientific understanding, it also appears that our microbial companions play an important role in evolution. A new study, published online on July 18 by the journal Science, has provided direct evidence that these microbes can contribute to the origin of new species by reducing the viability of hybrids produced between males and females of different species. [my emphasis]

This study provides the strongest evidence to date for the controversial hologenomic theory of evolution, which proposes that the object of Darwin’s natural selection is not just the individual organism as he proposed, but the organism plus its associated microbial community. (The hologenome encompasses the genome of the host and the genomes of its microscopic symbiotes.)

“It was a high-risk proposition. The expectation in the field was that the origin of species is principally driven by genetic changes in the nucleus. Our study demonstrates that both the nuclear genome and the microbiome must be considered in a unified framework of speciation,” said Associate Professor of Biological Sciences Seth Bordenstein who performed the study with post-doctoral fellow Robert Brucker.

They conducted their research using three species of the jewel wasp Nasonia. These tiny, match-head sized wasps parasitize blowflies and other pest flies, which make them useful for biological control.

“The wasps have a microbiome of 96 different groups of microorganisms,” [My emphasis]said Brucker. Two of the species they used (N. giraulti and N. longicornis) only diverged about 400,000 years ago so they are closely related genetically. This closeness is also reflected in their microbiomes, which are quite similar. The third species (N. vitripennis), on the other hand, diverged about a million years ago so there are greater differences in both its genome and microbiome, he explained.

The mortality of hybrid offspring from the two closely related species was relatively low, about 8 percent, while the mortality rate of hybrid offspring between either of them and N. vitripennis was quite high, better than 90 percent, the researchers established.

“The microbiomes of viable hybrids looked extremely similar to those of their parents, but the microbiomes of those that did not survive looked chaotic and totally different,” Brucker reported.

The researchers showed that the incompatibilities that were killing the hybrids had a microbial basis by raising the wasps in a microbe-free environment. They were surprised to find that the germ-free hybrids survived just as well as purebred larvae. But when they gave the germ-free hybrids gut microbes from regular hybrids, their survival rate plummeted.

“Our results move the controversy of hologenomic evolution from an idea to an observed phenomenon,” said Bordenstein. “The question is no longer whether the hologenome exists, but how common it is?”

 

 

 

July 19, 2013 Posted by | Medical and Health Research News | , , , , | Leave a comment

   

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