Posts about microbiome

Stanford Research Scientists Discover 99% of the Microbes Inside Us are Unknown to Science

Readers of this blog know I am fascinated by the human microbiome. It is amazing how much of our biology is determined by entities within us that are not us (at least not our DNA) (bacteria, viruses etc.). This whole area of study is very new and we have quite a bit to learn. There are scientists across the globe studying this area and learning a great deal.

Stanford study indicates that more than 99% of the microbes inside us are unknown to science

Of all the non-human DNA fragments the team gathered, 99 percent of them failed to match anything in existing genetic databases the researchers examined.

The “vast majority” of it belonged to a phylum called proteobacteria, which includes, among many other species, pathogens such as E. coli and Salmonella. Previously unidentified viruses in the torque teno family, generally not associated with disease but often found in immunocompromised patients, made up the largest group of viruses.

“We’ve doubled the number of known viruses in that family through this work,” Quake said. Perhaps more important, they’ve found an entirely new group of torque teno viruses. Among the known torque teno viruses, one group infects humans and another infects animals, but many of the ones the researchers found didn’t fit in either group. “We’ve now found a whole new class of human-infecting ones that are closer to the animal class than to the previously known human ones, so quite divergent on the evolutionary scale,” he said.

Related: We are Not Us Without The Microbes Within UsWebcasts on the Human MicrobiomePeople are Superorganisms With Microbiomes of Thousands of Species (2013)We Have Thousands of Viruses In Us All the Time (2015)Tracking the Ecosystem Within Us (2007)

We are Not Us Without The Microbes Within Us

I Contain Multitudes is a wonderful book by Ed Young on the microbes within us.

Time and again, bacteria and other microbes have allowed animals to transcend their basic animalness and wheedle their way into ecological nooks and crannies that would be otherwise inaccessible; to settle into lifestyles that would be otherwise intolerable; to eat what they could not otherwise stomach; to succeed against their fundamental nature. And the most extreme examples of this mutual assured success can be found in the deep oceans, where some microbes supplement their hosts to such a degree that the animals can eat the most impoverished diets of all – nothing.

This is another book exploring the wonders of biology and the complexity of the interaction between animals and microbes.

For hundreds of years, doctors have used dioxin to treat people whose hearts are failing. The drug – a modified version of a chemical from foxglove plants – makes the heart beat more strongly, slowly, and regularly. Or, at least, that’s what it usually does. In one patient out of every ten, digoxin doesnt’ work. Its downfall is a gut bacterium called Eggerthella lenta, which converts the drug to an inactive and medically useless form. Only some strains of E. lenta do this.

The complex interactions within us are constantly at work helping us and occasionally causing problems. This obviously creates enormous challenges in health care and research on human health. See related posts: Introduction to Fractional Factorial Designed Experiments, “Grapefruit Juice Bugs” – A New Term for a Surprisingly Common Type of Surprising Bugs and 200,000 People Die Every Year in Europe from Adverse Drug Effects – How Can We Improve?.

Every person aerosolized around 37 million bacteria per hour. This means that our microbiome isn’t confined to our bodies. It perpetually reaches out into our environment.

Avoiding bacteria is not feasible. Our bodies have evolved with this constant interaction with bacteria for millions of years. When we are healthy bacteria have footholds that make it difficult for other bacteria to gain a foothold (as does our immune system fighting off those bacteria it doesn’t recognize or that it recognized as something to fight).

A few pages later he discusses the problem of hospital rooms that were constantly cleaned to kill bacteria and largely sealed to reduce airflow. What happened is those bacteria the sick people had in them were the bacteria that were flourishing (the number of other bacteria to compete for space was small). Opening the windows to welcome the outside air resulted in better results.

Outdoors, the air was full of harmless microbes from plants and soils. Indoors, it contained a disproportionate number of potential pathogens, which are normally rare or absent in the outside world

Human health is a fascinating topic. It is true antibiotics have provided us great tools in the service of human health. But we have resorted to that “hammer” far too often. And the consequences of doing so is not understood. We need those scientists exploring the complex interactions we contain to continue their great work.

Related: People are Superorganisms With Microbiomes of Thousands of Species (2013)Bacteria are Always Living in Our Bodies (2014)Gut Bacteria Explored as Medical Treatment – even for Cancer

Webcasts on the Human Microbiome

The human microbiome is a very interesting aspect of our health and biology.

The 99% figure they quote is mainly silly. It might be technically accurate, but it is much more misleading than accurate (if it is accurate). We have more non-human cells than human but those cells are much smaller and we are overwhelmingly made up of human cells by weight (95+%).

The complexity of healthy bodies is far from understood. It is interesting to watch our understanding of the balancing act going on inside of us. Many foreign “invaders” are critical to our health.

Related: People are Superorganisms With Microbiomes of Thousands of SpeciesPeople Have More Bacterial Cells than Human CellsFighting Superbugs with Superhero BugsWe Have Thousands of Viruses In Us All the Time

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Lots of Bacteria are Always Living in Our Bodies

My response to a question on Reddit – Ask Science:

Let’s say you get infected with a bacterium that causes annoying, but totally non-dangerous symptoms. If you just try to “live with it,” will your immune system eventually kill it, or does killing bacteria require antibiotics in all cases?

Your body definitely kills lots of bacteria.

Your body also has tons of bacteria all the time (many doing much more good than they do harm). These bacteria also compete with each other.

So your “existing” bacteria kill off others all the time too (you have lots of different types of bacteria full time in your body – they often settle into niches and fight off any others , which is normally good as they are long term residents your body has learned to live with them).

Also like everything bacteria die off themselves – though if the conditions are right they are multiplying like crazy so that exceeds die off.

An astonishing number and variety of microbes, including as many as 400 species of bacteria, help humans digest food, mitigate disease, regulate fat storage, and even promote the formation of blood vessels.

According to estimates, phages destroy up to 40 percent of the bacteria in Earth’s oceans each day.

Staphylococcal food poisoning – an example of bacteria infection my body dealt with quickly.

People talk about genetics impact on getting cavities and impact of brushing and flossing well. Also the makeup of bacteria can help or hurt. If your mouth is home to certain bacteria tooth decay is less likely, home to others it is more likely. They tend to remain fairly steady (a certain makeup of bacteria will be consist for a person over the long term – not perfectly that way but tend that way). A UCLA microbiologist developed a mouthwash to try and ceed your mouth with good bacteria and oust the bad guys.

Related: People Have More Bacterial Cells than Human CellsHuman Gene Origins: 37% Bacterial, 35% Animal, 28% Eukaryotic

Microbes Flourish In Healthy People

Bugs Inside: What Happens When the Microbes That Keep Us Healthy Disappear? by Katherine Harmon

The human body has some 10 trillion human cells—but 10 times that number of microbial cells. So what happens when such an important part of our bodies goes missing?

“Someone who didn’t have their microbes, they’d be naked,” says Martin Blaser, a professor of microbiology and chair of the Department of Medicine at New York University Langone Medical Center in New York City.

Even though it is such an apparently integral and ancient aspect of human health, scientists are still grasping for better ways to study human microbiota—before it changes beyond historical recognition. Borrowing models from outside of medicine has helped many in the field gain a better understanding of this living world within us. “The important concept is about extinctions,” Blaser says. “It’s ecology.”

The first step in understanding these systems is simply taking stock of what archaea, bacteria, fungi, protozoa and viruses are present in healthy individuals. This massive micro undertaking has been ongoing since 2007 through the National Institutes of Health’s (NIH) Human Microbiome Project. So far it has turned up some surprisingly rich data, including genetic sequencing for some 205 of the different genera that live on healthy human skin.

Despite the flood of new data, Foxman laughs when asked if there is any hope for a final report from the Human Microbiome Project any time soon. “This is the very, very beginning,” she says, comparing this project with the NIH’s Human Genome Project, which jump-started a barrage of new genetic research. “There are basic, basic questions that we don’t know the answers to,” she says, such as how different microbiota are between random individuals or family members; how much microbiota change over time; or how related the microbiota are to each other on or inside a person’s body.

Related: Microcosm by Carl ZimmerTracking the Ecosystem Within UsAlligator Blood Provides Strong Resistance to Bacteria and VirusesBeneficial Bacteria

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