A doctor answers the internet's burning questions about the gut

Visualize the different parts of the digestive tract, a roughly 30-foot tube which runs from our mouths to our rear.

A technical review of what researchers know about the gut microbiome

This overview from the National Institutes of Health provides a deeper (but still accessible) look at the different bacteria in the gut, how the microbiome develops through life, its purpose, and more.

See how the gut and the brain communicate through a bundle of nerves running from the brain to the digestive tract, serving as both a physical and chemical link.

Learn how colorectal cancer is linked to the American diet and chronic inflammation

A University of South Carolina colon cancer researcher offers insights from his own research and notes that more exercise, social support, and eating fruits, vegetables, legumes, and foods like fish and olive oil—often called the Mediterranean diet—are associated with better health—and could improve our colons.

The gut microbiome—a complex community of up to 100 trillion microbes—has a changing composition, influenced by our life stage, diet, medications, environment, and other factors.

Vitamin B1 is linked to gut motility—helping fight constipation—in 2026 research

A study published in early 2026 found a link between vitamin B1 and the successful movement of food through your GI tract, known as gut motility. The work incorporated genetic and survey data about poop frequency to identify genes associated with gut motility and then separately linked poop frequency data with how much vitamin B1 people ingested, theorizing that the vitamin supports the production of acetylcholine, a neurotransmitter that stimulates GI system contractions.

What's next for gut microbiome science?

A Stanford microbiologist explores what we don't yet know about the gut microbiome—such as whether we can engineer the bacterial species within it—and the current scientific advances in the field.

Long-haul COVID: What doctors want patients to know

Long COVID continues to be a medical mystery, but some parts of the puzzle are falling into place. Learn more from intensivist Devang Sanghavi, MD.

Hear a finance professor answer questions about investing

From stocks and index funds to gold, a business professor at Duke University answers questions from the internet about investing.

An Egyptologist answers questions from the internet

Professor of Egyptology and Archaeology Laurel Bestock answers your questions about ancient Egypt from X. What did ancient Egyptians sound like? Why is King Tut so enduringly popular? What ancient Egyptian medicine and tools do we still use in modern times?

In 2026, University of Cambridge researchers reported that a group of gut bacteria called CAG-170 may be a key marker of good health, occurring far more often in healthy individuals and less commonly in people with chronic diseases.

Fecal transplants can help treat infections by transplanting healthy gut bacteria from a donor into a patient's gastrointestinal tract using samples of human waste, which are turned into a liquid mixture and often delivered via a colonoscopy procedure.

There are up to 100 trillion microbes in the gut, and maintaining the relative balance in this ecosystem is important for our health.

Patients are messaging their doctors online more than ever—recent research suggests portal messages have risen by 157% since 2020.

Can the gut microbiome drive addiction?

New research suggests an imbalance of gut microorganisms may influence the likelihood of addiction and addictive behaviors by increasing the severity of withdrawal symptoms, triggering brain inflammation in regions of impulse control, and more.

Bacteria in our intestine influence the brain via the gut-brain axis.

How the microbiome affects your health

The gut microbiome is so influential to overall human health that some researchers consider it a separate organ. Its conditions, influenced by environmental and lifestyle factors such as medication and exercise, contribute to immunity, metabolism, inflammation, medical treatment efficacy, brain development and function, and the development of disorders and diseases, including asthma, depression, inflammatory bowel disease, and Alzheimer's.

Exercise causes diet-independent changes in the gut microbiome.

Researchers generally group gut bacteria into six different categories, with varying amounts of these microbes residing in different parts of the digestive tract.

What constitutes a 'healthy' diet?

A natural diet, typically high in plant-based foods and low in processed foods, appears to be the main contributor to a healthy, diverse gut microbiome.

Farts are tiny status reports from our gut microbiome, with American adults typically passing gas more than 30 times daily.

Scientists seeking gut insights are attaching flatulence sensors to volunteers' underwear

This fart-tracking device detects gas generated in the gut, providing insights about gut microbial activity. The underwear sensors measure a component of what is technically called flatus—digestive system gas.

How fecal transplants work

1,700 years ago, Chinese alchemist Ge Hong was renowned for his soup that could cure diarrhea-stricken patients. It had a surprising secret ingredient: feces. While it might seem unwise to consume feces, exciting new research suggests that taking...

Food passes through the digestive system via muscle movement known as peristalsis, a rippling contraction that pushes food onward through tubular organs.

Trillions of bacteria, viruses, fungi, protists, and archaea live in our guts, producing a wide range of molecules, hormones, and more—underscoring the immune system's pivotal role in the microbiota-gut-brain axis.

13 unanswered questions about black holes

Here's a quick rundown on black hole basics, the cosmic enigmas digesting massive swaths of the universe and destabilizing our fundamental ideas of space, time, and matter. Learn how they got their name, what happens in the unfortunate instance you fall into one, and more with this list of 13 questions about black holes.

Pooping or puking out pathogens is sometimes recommended with food poisoning

Sometimes stopping food poisoning-linked diarrhea with over-the-counter medications is a bad idea because it may prolong illness. Doctors can advise you if your diarrhea or vomiting is severe about what medications to take and when, but generally doctors recommend trying to stay hydrated during a bout of food poisoning and letting the body naturally remove pathogens from the body via vomiting or diarrhea, as needed.

The gut microbiome may play a major role in autoimmune disease and symptom flare-ups

Certain unhealthy foods can promote gut bacterial growth and inflammation in the lining of the gut, potentially disrupting its lining—leading to a leaky gut that may allow pathogens to dribble out into the bloodstream, fueling further inflammation that can both cause disease flare-ups and set the stage for future disease development.

Listen to how the gut microbiome influences your emotions

The gut-microbiome connection may involve the enteric nervous system, a collection of hundreds of millions of neurons throughout the gut that transmit signals up the vagus nerve to the brain.

The gut microbiome's community of viruses is collectively known as the virome, but most of its viruses remain unidentified.

What is the gut microbiome?

The gut microbiome is a microscopic ecosystem that runs off the work of microbes in the digestive tract. These workers make getting energy from food possible. What and how that energy manifests depends on what building blocks these microbes have to work with, meaning their composition and functions are strongly influenced by diet. Gut microbes have their own genes, which affect how a person's genes act.

Explore these images to better understand why food poisoning makes you feel nauseous.

What happens when the gut microbiome is out of whack?

An imbalance in gut microbiome flora can lead to a condition known as dysbiosis. This condition is typically characterized by a drop in microbiota diversity and an increase in harmful unicellular and acellular organisms, such as viruses, that can negatively impact the host's immune system and overall health. Genetics, infections, dietary choices, antibiotics, food additives, artificial sweeteners, and other lifestyle and environmental factors can cause dysbiosis.

Most things you would get tested for at the doctor’s office are influenced by circadian rhythm

In this video, a Salk Institute Researcher offers daily habit tips focused on aligning with your circadian rhythms. She notes heart rate and blood pressure are highest in the afternoon, for example, and there’s a triglyceride peak in the morning. Generally, she says, it’s a good idea to schedule your doctor’s checkups at the same time of day each year so there’s consistency across your data.

Scientists now know why wombats poop cubes

For years, scientists have been wondering why wombat poop is cube-shaped (yes, really). Now, they say they have got to the bottom of the mystery.

How humans digest food

Every day, the average human eats close to six pounds of food—all of which must be processed by the digestive system. Ten organs collaborate to transform food that the mouth chews into the energy needed to stay alive. (Stretched out, these organs...

Specific gut microbiome 'fingerprints' are associated with cancer recurrence, with up to 94% accuracy.

Probiotics, which are living bacteria and yeasts, are not recommended for most patients.

The strange endurance of consuming blood for health

Blood's importance to humanity is best summarized this way: without it, we die. This importance naturally begets assumptions about its medicinal properties, many of which appear accessible through drinking or eating the fluid connective tissue. This article details the history of blood drinking, from ancient Roman gladiators to modern-day sanguinarians.

Without liver bile, human poop would be a pale silver color

Stomach acid and enzymes break down food into smaller particles, expelling a semi-fluid mass called chyme into the small intestine, where bile is added. As the intestines absorb nutrients and water, the chyme solidifies and changes color.

Gut bacteria are evolving and can acquire as many as 100 new genes per year, on average.

Small ways to improve your health today: an animated guide

What are some ways that you could start making a positive impact on your health today? This animated gallery overviews several health topics, including sleep and hydration, and offers ways to improve that aspect of your life. Clicking on the...

What is a microbiome (and why are they important)?

Jump to: What is the microbiome? How microbiota benefit the body The role of probiotics Can diet affect one’s microbiota? Future areas of research What is the microbiome? Picture a bustling city on…

The ABCs and FAQs on GMOs from the WHO.

GMOs (or genetically modified organisms) are a subject of great debate in the food world…but how come? GMOs are organisms whose genetic materials have been altered in a way that does not occur naturally in order to create a product that has a...

Addressing lifestyle factors, which influence inflammation, can cure some chronic diseases

In this video, a physician claims that he reversed a patient's Type 2 diabetes in six weeks by addressing inflammation drivers such as diet. More broadly, he argues that society needs to better consider and address numerous disease factors that are modulated by inflammation, such as stress, sleep, diet, and movement.

Can we speed up our metabolisms?

Listen to this 31-minute podcast to better understand what science knows and doesn't know about metabolism, as well as the only thing that seems capable of changing it. Scientists understand that the difference between a so-called “fast” and “slow” metabolism does not affect one’s ability to lose weight.

Scientists from the frontline discuss the future of antibiotics and superbugs

Superbugs are a very real problem, but researchers around the world are working to advance our understanding of these pathogens and develop new medicines. This podcast talks with several scientists on the frontier of superbug research, offering insight into what we know—and what the future of medicine may look like.

Thoughts from an anonymous Michelin inspector

An anonymous Michelin inspector answers the most common questions about their job and explains how reviewing and awarding stars works. Covering everything from how they decide what to order to advice for young chefs, get a peek into the details of one of the most influential restaurant reviewing jobs.

Debunking myths about weight loss drugs

Business Insider delves into the research on GLP-1 to highlight the good and bad aspects other stories overlook. Few make it clear that GLP-1 drugs simply don’t work for many people. This deep dive raises a number of questions about the future of GLP-1 and how they will be used.

Some animals, including certain tropical ants, have little or no microbial populations in their gut, upending the idea that all animals rely on this ecosystem to help maintain their health and proper functioning.