Zoom inside your microbiome with the Museum’s exhibition The Secret World Inside You.
Your digestive tract is home to around 100 trillion bacteria—more than all the stars in the Milky Way galaxy.
The stomach hosts very few microbes, however. The majority of those trillions of microbes are housed in the large intestine, where food ferments after digestion.
Visit The Secret World Inside You to learn more.
Have you ever wondered if microbes are… animals? Bacteria? Consumers? Thanks to Google, we know you have! We found the most commonly searched microbial questions, from A to Z, and put them to Rob DeSalle and Susan Perkins, curators of the Museum's new exhibition about the human microbiome. We are answering all of your #MicrobeWeek questions in this article.
Though invisible to the naked eye, your skin is covered in microbes! Skin bacteria get nutrients like sugars, vitamins and amino acids from many materials found in skin. They also release many compounds, some of which can contribute to our health. Skin bacteria eat up things like:
Skin bacteria spit out things like:
Learn more about the microbiome of your skin in the new exhibition, The Secret World Inside You, now open at the Museum.
Happy New Year from the microbes at the American Museum of Natural History! Resolve to learn about the community of trillions that lives inside each and every one of us in the new exhibition, The Secret World Inside You.
Your large intestine is a fermentation factory. Trillions of microbes ferment fiber and other food you can’t digest, producing useful nutrients and protecting your gut lining from inflammation.
Additionally, many cells in your gut produce neurotransmitters—chemicals that affect your brain. Serotonin, for instance, influences mood, sleep and memory. Many antidepressants alter serotonin levels—and so do many microbes. In fact, about 80% of serotonin is produced in the gut, not the brain.
Learn more about The Secret World Inside You, now on view at the Museum.
How much do you know about the human microbiome? Test your knowledge about microbes that live in and on us in this 10-question quiz!
Your skin is the largest organ of your body. It is also a diverse microscopic landscape!
Skin makes for a sprawling countryside of hills and valleys, cracks and crevices, smooth slopes and rough terrain. In each of these regions, you can find a variety of bacteria, fungi, and other microbes making themselves at home.
Differences in skin temperature, texture, thickness, humidity, and chemistry help determine which kinds of microbes live where, and similar parts of your body can host very different microbiomes. For instance, the microbiomes of left and right hands are not the same. One hand may be sweatier or oilier than the other, and the two often touch different objects.
What are microbes? Are they good or bad? What do microbes look like and do animals have them too?
You have questions, and microbiologist Susan Perkins has answers! Perkins is the co-curator of the new Museum exhibition, The Secret World Inside You, which delves into the human microbiome.
Watch her series of video explainers, and learn more about microbes!
By far the largest population of bacteria in the human body is found in the colon. The majority are anaerobic, which means they don’t require oxygen and, of these, species of the genus Bacteroides are among the most common.
Outside the gut, strains of Bacteroides can cause abscesses in the abdomen, brain, liver, pelvis, and lungs, as well as bacteremia, an infection of the bloodstream. But in the colon, they serve important functions, breaking down carbohydrates, producing enzymes specifically designed to deal with different foods, and extracting energy from those foods. One species, B. fragilis, appears to stimulate immune cells called regulatory T-cells, which restrain more aggressive inflammatory T-cells, which can trigger colitis and other disorders.
Researchers are also beginning to tease out the possible relationship between the overall makeup of a person’s gut microbiome and a propensity toward obesity, in which it is suspected Bacteroides may play a role. In any case, the usefulness and ubiquity of bacteria in the colon probably can’t be overstated. Three-quarters of human feces is water and, of the remaining quarter, one-third is composed of bacteria—or as Giulia Enders, author of Gut: The Inside Story of Our Body’s Most Underrated Organ, describes them, “gut flora that ended their careers in the digestive business and are ready to retire from the workplace.”
Learn more about the microbiome in The Secret World Inside You, a new exhibition at the Museum.
Image: A human T-cell, seen through a scanning electron microscope. Courtesy of National Institute of Allergy and Infectious Diseases
How do you make a Thanksgiving meal? Turkey, gravy, cranberries and mashed potatoes may all come to mind, but what about microbes? Microbes help make many of our favorite holiday dishes!
Just like any form of life, microbes need energy. To get it, they consume molecules they come into contact with for sustenance. No metabolism is perfect, though, and even the smallest meals produce waste products, a process known as fermentation. A microbe's trash can be a treasure to us, though—these waste molecules are key ingredients in the fermented foods and drinks that are cornerstones of cuisine around the world.
Fermentation works by feeding sugars to microbes like yeast, a fungus, or a bacteria such as Lactobacillus. The two types of microbes have different means of processing the carbohydrates they dine on. For bacteria, the end product of fermenting sugar is a simple molecule called lactic acid, a weak acid with a rather sour taste. Yeast, one the other hand, produces a molecule called ethanol, the inebriating agent in alcohol. Humans figured out early on that both of these waste products could create tasty dishes while also helping food keep longer, as demonstrated in the three recipes below.
Pickling
Fermenting vegetable matter with bacteria (specifically strains of Lactobacillus) produces sour-flavored, long-lasting treats. Better known as "pickling," this process is used in cuisines all around the world to crafts foods from kosher dills to kimchi. The process is thought to have originated thousands of years ago in Egyptian society.
Beer
Fermenting grains or fruits with yeast is a tradition at least as old as pickling, and one that's also known around the world. Luckily for folks who enjoy a beer or glass of wine with dinner, yeast converts sugars into alcohol instead of lactic acid. While the two substances have similar chemical formulas (lactic acid consists of six hydrogen molecules, teamed with three carbon and three oxygen atoms, while alcohol binds six hydrogen atoms to a pair of carbon atoms and a single oxygen atom) they do very different things when they come in contact with our bodies and communicate with our brains—hence the difference between sour-tasting pickles and inebriating beer.
Sourdough Bread
But what happens when a concoction combines Lactobacillus and yeast? Sourdough bread is a good example of this forced symbiosis. Bakers have taken advantage of a wide array ofLactobacillus species and their close relatives to produce three kinds of sourdough bread. The lactic acid from the bacteria and carbon dioxide produced by the fermentation of yeast give this bread its distinctive tangy taste and fluffy texture. The fermentation process also converts the linoleic acid in bread flour into fatty acids that resist the growth of mold and help the loaf stay edible longer, a quality that made this food a favorite among gold surveyors in California. In addition, the presence of yeast means that sourdough freshly out of the oven will have some alcohol in it, although this content evaporates as time goes by.
Cheese
Lactobacillus bacteria consume milk in the guts of infants—and in fermented milk products like yogurt, sour cream and cheese. They produce lactic acid, which keeps fungi and bacteria from spoiling yogurt—and keeps disease-causing microbes from infecting people, too. That’s why they are a popular probiotic.
Learn more about microbes in The Secret World Inside You, now open at the Museum!
Happy Thanksgiving from the American Museum of Natural History! This year, we’re thankful for our microbiome, which is particularly helpful in digesting the traditional holiday feast many of us will be enjoying today.
Millions of microbes enter your body at every meal. Indeed, after your skin, the digestive system is the main place where your body comes in contact with microbes. But unlike your skin, your digestive system is a warm, sheltered space—and it’s filled with food. It’s the perfect spot for microbes. So it’s no surprise that the vast majority of your body’s microbiome is inside your digestive tract. Your digestive tract is home to around 100 trillion bacteria—more than all the stars in the Milky Way galaxy. Many fibers from food, including cellulose, cannot be digested by the human body alone—but resident bacteria produce enzymes that can break them down.
Stomach Almost no nutrients are absorbed in the stomach. It is filled with harsh acids that kill most bacteria. Very few live here permanently.
Small intestine Your small intestine is about 20 feet (6 meters) long. Most of your food is digested in your small intestine. Sugar, fat and protein are broken down and absorbed, with the help bacteria. Large intestine Your large intestine is where fibers ferment, frequently for 40 hours. Trillions of microbes ferment fiber and other food you can’t digest, producing useful nutrients and protecting your gut lining from inflammation.
MY GUT? SO WHAT? Microbes in your gut play many important roles in your body. They help with digestion, immune regulation, disease prevention, healing and protecting your gut lining, appetite control, brain development and even emotion.
Learn more about your microbiome in The Secret World Inside You, now open at the Museum!
By far the largest population of bacteria in the human body is found in the colon. The majority are anaerobic, which means they don’t require oxygen and, of these, species of the genus Bacteroides are among the most common.
Outside the gut, strains of Bacteroides can cause abscesses in the abdomen, brain, liver, pelvis, and lungs, as well as bacteremia, an infection of the bloodstream. But in the colon, they serve important functions, breaking down carbohydrates, producing enzymes specifically designed to deal with different foods, and extracting energy from those foods. One species, B. fragilis, appears to stimulate immune cells called regulatory T-cells, which restrain more aggressive inflammatory T-cells, which can trigger colitis and other disorders.
Take a look at Toxoplasma gondii, you may be infected with it. Roughly a third of all humans are infected with the parasite Toxoplasma gondii, which can alter the behavior of mice—and it appears to influence our behavior as well. Studies suggest that infected men become more reckless, break more rules, and dress more sloppily. Infected women become more sociable and wear more expensive clothing. Both have slower reaction times and get in more car accidents. A digital rendering of this parasite, which appears in the exhibition’s interactive table, is pictured here.
Learn more about your microbiome in the new exhibition, The Secret World Inside You, now open at the Museum.
Image: © AMNH
Fermenting grains or fruits with yeast is an age-old tradition, and one that's known around the world. While beer has many different flavors and styles, the basic recipe includes water, hops, grain, malt, and yeast. Luckily for folks who enjoy a beer or glass of wine with dinner, yeast converts sugars into alcohol instead of lactic acid. While the two substances have similar chemical formulas (lactic acid consists of six hydrogen molecules, teamed with three carbon and three oxygen atoms, while alcohol binds six hydrogen atoms to a pair of carbon atoms and a single oxygen atom) they do very different things when they come in contact with our bodies and communicate with our brains—hence the difference between sour-tasting pickles and inebriating beer.
Image: AMNH/M.Fearon
Just like any form of life, microbes need energy. To get it, they consume molecules they come into contact with for sustenance. No metabolism is perfect, though, and even the smallest meals produce waste products, a process known as fermentation. A microbe's trash can be a treasure to us, though—these waste molecules are key ingredients in the fermented foods and drinks that are cornerstones of cuisine around the world.
Fermentation works by feeding sugars to microbes like yeast, a fungus, or a bacteria such as Lactobacillus. The two types of microbes have different means of processing the carbohydrates they dine on. For bacteria, the end product of fermenting sugar is a simple molecule called lactic acid, a weak acid with a rather sour taste. Yeast, one the other hand, produces a molecule called ethanol, the inebriating agent in alcohol. Humans figured out early on that both of these waste products could create tasty dishes while also helping food keep longer, as demonstrated in the three recipes below.
Pickling
Fermenting vegetable matter with bacteria (specifically strains of Lactobacillus) produces sour-flavored, long-lasting treats. Better known as "pickling," this process is used in cuisines all around the world to crafts foods from kosher dills to kimchi. The process is thought to have originated thousands of years ago in Egyptian society.
Beer
Fermenting grains or fruits with yeast is a tradition at least as old as pickling, and one that's also known around the world. Luckily for folks who enjoy a beer or glass of wine with dinner, yeast converts sugars into alcohol instead of lactic acid. While the two substances have similar chemical formulas (lactic acid consists of six hydrogen molecules, teamed with three carbon and three oxygen atoms, while alcohol binds six hydrogen atoms to a pair of carbon atoms and a single oxygen atom) they do very different things when they come in contact with our bodies and communicate with our brains—hence the difference between sour-tasting pickles and inebriating beer.
Sourdough Bread
But what happens when a concoction combines Lactobacillusand yeast? Sourdough bread is a good example of this forced symbiosis. Bakers have taken advantage of a wide array ofLactobacillus species and their close relatives to produce three kinds of sourdough bread. The lactic acid from the bacteria and carbon dioxide produced by the fermentation of yeast give this bread its distinctive tangy taste and fluffy texture. The fermentation process also converts the linoleic acid in bread flour into fatty acids that resist the growth of mold and help the loaf stay edible longer, a quality that made this food a favorite among gold surveyors in California. In addition, the presence of yeast means that sourdough freshly out of the oven will have some alcohol in it, although this content evaporates as time goes by.
Learn more about microbes in the new exhibition, The Secret World Inside You, now open!
Images: AMNH/M.Fearon
A behind-the-scenes Microbiome Monday!
In the Museum’s exhibition studio, the finishing touches are put on a highly magnified model of human skin cells, upon which rod-shaped bacteria called Bacillus subtilis (shown in purple) are locked in battle with a fungus (green filaments) that causes athlete’s foot. Like most microbes typically found on skin, these Bacillus bacteria don’t harm us, and they may protect us from treacherous intruders.
See the finished model in the new exhibition, The Secret World Inside You, now open!
AMNH/R.Mickens
Each of us has a community of microbes that lives in our digestive system. Scientists call this community our gut microbiome. It plays many important roles in our bodies, like helping to digest food, regulating our immune system, preventing diseases, and even affecting our appetites and our emotions.
Many things, like what we eat and drink, who we interact with, and the medicines that we take, influence the kinds of microbes that live in our gut. A diverse microbiome is good for our health! Learn more about this topic in the new exhibition, The Secret World Inside You.
In the new card game, Gutsy, collect microbes, and learn about what helps, and harms, your microbiome. Download the game for free or purchase the deck from the Museum store!
