Skip to main content

microbe

Girl and her micrbiomeMany people still regard bacteria and other microbes just as disease-causing germs. But it’s a lot more complicated than that. In fact, it’s become increasingly clear that the healthy human body is teeming with microorganisms, many of which play essential roles in our metabolism, our immune response, and even our mental health. We are not just an organism, we are a “superorganism” made up of human cells and microbial cells—and the microbes outnumber us! Fueling this new understanding is NIH’s Human Microbiome Project (HMP), a quest begun a decade ago to explore the microbial makeup of healthy Americans.

About 5 years ago, HMP researchers released their first round of data that provided a look at the microbes present in the mouth, gut, nose, and several other parts of the body [1]. Now, their second wave of data, just published in the journal Nature, has tripled this treasure trove of information, promising to further expand our understanding of the human microbiome and its role in health and disease [2]. For example, the new DNA data offer clues as to the functional roles those microbes play and how those can vary over time in different parts of the human body and from one person to the next.

(more…)

Posted In: Health, Science

Tags: , , , , , , , , , , , , ,

T mu in a mouse colon

Caption: Scanning electron microscopy image of T. mu in the mouse colon.
Credit: Aleksey Chudnovskiy and Miriam Merad, Icahn School of Medicine at Mount Sinai

Recently, we humans have started to pay a lot more attention to the legions of bacteria that live on and in our bodies because of research that’s shown us the many important roles they play in everything from how we efficiently metabolize food to how well we fend off disease. And, as it turns out, bacteria may not be the only interior bugs with the power to influence our biology positively—a new study suggests that an entirely different kingdom of primarily single-celled microbes, called protists, may be in on the act.

In a study published in the journal Cell, an NIH-funded research team reports that it has identified a new protozoan, called Tritrichomonas musculis (T. mu), living inside the gut of laboratory mice. That sounds bad—but actually this little wriggler was potentially providing a positive benefit to the mice. Not only did T. mu appear to boost the animals’ immune systems, it spared them from the severe intestinal infection that typically occurs after eating food contaminated with toxic Salmonella bacteria. While it’s not yet clear if protists exist that can produce similar beneficial effects in humans, there is evidence that a close relative of T. mu frequently resides in the intestines of people around the world.

(more…)

Posted In: Health, Science

Tags: , , , , , , , , , , , , , , , , , , , , , , , ,

BioArt-Berkmen and PenilAs long as researchers have been growing bacteria on Petri dishes using a jelly-like growth medium called agar, they have been struck by the interesting colors and growth patterns that microbes can produce from one experiment to the next. In the 1920s, Sir Alexander Fleming, the Scottish biologist who discovered penicillin, was so taken by this phenomenon that he developed his own palette of bacterial “paints” that he used in his spare time to create colorful pictures of houses, ballerinas, and other figures on the agar [1].

Fleming’s enthusiasm for agar art lives on among the current generation of microbiologists. In this short video, the agar (yellow) is seeded with bacterial colonies and, through the magic of time-lapse photography, you can see the growth of the colonies into what appears to be a lovely bouquet of delicate flowers. This piece of living art, developing naturally by bacterial colony expansion over the course of a week or two, features members of three bacterial genera: Serratia (red), Bacillus (white), and Nesterenkonia (light yellow).

(more…)

Posted In: Science, Video

Tags: , , , , , , , , , , ,

Bacteroides thetaiotaomicron

Caption: Bacteroides thetaiotaomicron (white) living on mammalian cells in the gut (large pink cells coated in microvilli) and being activated by exogenously added compounds (small green dots) to express specific genes, such as those encoding light-generating luciferase proteins (glowing bacteria).
Credit: Janet Iwasa, Broad Visualization Group, MIT Media Lab

When you think about the cells that make up your body, you probably think about the cells in your skin, blood, heart, and other tissues and organs. But the one-celled microbes that live in and on the human body actually outnumber your own cells by a factor of about 10 to 1. Such microbes are especially abundant in the human gut, where some of them play essential roles in digestion, metabolism, immunity, and maybe even your mood and mental health. You are not just an organism. You are a superorganism!

Now imagine for a moment if the microbes that live inside our guts could be engineered to keep tabs on our health, sounding the alarm if something goes wrong and perhaps even acting to fix the problem. Though that may sound like science fiction, an NIH-funded team from the Massachusetts Institute of Technology (MIT) in Cambridge, MA, is already working to realize this goal. Most recently, they’ve developed a toolbox of genetic parts that make it possible to program precisely one of the most common bacteria found in the human gut—an achievement that provides a foundation for engineering our collection of microbes, or microbiome, in ways that may treat or prevent disease.

(more…)

Posted In: Health, Science

Tags: , , , , , , , , , , , , , , ,