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.

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...

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

The American Gastroenterological Association in 2020 concluded that although almost 4 million American adults have taken some form of probiotics, health claims about them are not backed in strong evidence. They only recommend their use for a few specific situations: to prevent Clostridioides difficile infection in people taking antibiotics that kill gut bacteria, to prevent necrotizing enterocolitis in preterm infants, and for the management of a complication of inflammatory bowel disease called pouchitis.

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

Exercise causes diet-independent changes in the gut microbiome

Cardiovascular exercise has been found to boost the gut's population of beneficial bacteria, and exercise overall decreases the likelihood of developing a "leaky gut," a condition in which a porous gut lining allows bacteria to leak into the bloodstream and cause inflammation.

Hookworm infection, though risky, may help fight certain health conditions

Early clinical trial research suggests that the parasites trigger the production of specific proteins that quiet our immune systems. This keeps the parasites from being killed, but it also quiets the inflammatory response that underpins allergies, type 2 diabetes, celiac disease, and other autoimmune conditions. Researchers still caution that infection with too many hookworms can cause serious medical complications and that this is not a standardized or approved medical treatment.

Gut microbiome experiments involving transfers of gut microbes from depressed people to rodents indicate that the rodents may then display depression-like symptoms, underscoring that gut microbes may influence behavior and personality more than previously known.

Gut microbiome rewrites may help reduce allergies

Researchers are investigating different strategies to determine if one day they could give people a combination of gut microbes to set them up for fewer allergies. In animal research, scientists have already prevented severe allergic responses in allergy-prone mice—supplying them with gut microbes from healthy, non-allergic human babies.

Fungi have been used to restore island habitats in the central Pacific

After removing 1.5 million invasive coconut palm trees and eradicating the black rats that fed on them, as well as seabirds and crabs, conservationists working with the US Fish and Wildlife Service identified areas where fungi could be transplanted to provide nutrients to native trees. These trees serve as nesting sites for seabirds whose guano nourishes coral reefs.

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.

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.

Examining the potential of the emerging field of insect-based bioremediation

Also known as entomoremediation, the novel approach uses larvae and adult insects, including their gut microbiomes and associated enzymes, to extract or degrade pollutants. As of 2025, research has shown that black soldier flies can degrade a wide range of antibiotics, highlighting their potential for bioremediating antibiotic-contaminated organic waste.

Recombinant DNA technology turns microorganisms into protein factories

Genes for molecules such as insulin can be inserted into loops of bacterial DNA called plasmids and reinserted into bacteria. Once placed in fermentation tanks, these bacteria use the gene to produce these molecules, which are then harvested and purified for eventual use.

Pig-to-human transplants have raised concerns about pig living conditions

Pigs are the current first choice for xenotransplantation procedures, yet such work gives some researchers and animal welfare advocates pause. Concerns include that pigs would have a poor quality of life since the animals must live in a strictly-controlled, hyper-clean environment to avoid risky pathogens.

Sewage on cruise ships is cleaned onboard by bacteria and advanced filtration systems

A cruise ship's onboard sewage plant processes black water, human waste or sewage, and gray water, wastewater from sinks, showers, and washing machines. Treated water is stored until the ship reaches a distance where it can legally discharge it.

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.

This scientist treated her own cancer

Virologist Beata Halassy treated her own breast cancer by injecting the tumor with lab-grown viruses. Though this self-treatment worked, it has not been approved for widespread use. Read to learn more about her fascinating experience, and how it has led to conversations about safety and ethics.

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.

Research suggests the cleanliness of the ISS may make astronauts unhealthy

The International Space Station's sterile conditions deprive astronauts of the opportunity to strengthen their immune systems through microbial exposure. To address this problem, future missions may use probiotic-based cleaners and foster diverse microbes in space habitats.

‘Hope for Healing’: The first-ever use of an in utero stem cell treatment

In 2023, researchers at UC Davis performed the first-ever fetal stem cell transplant, attempting to cure a case of spinal bifida prior to childbirth using stem cells derived from the placenta. The trial, and others including an effort to treat muscular dystrophy, highlight the potential power of stem cell therapy.

A clinical trial is underway in 2026 to help kidney transplant recipients avoid a lifetime of immunosuppressing drugs

This later-stage clinical trial, in Chicago and Taiwan, evaluates the efficacy and safety of a new cellular therapy that may be swapped in for immunosuppressing drugs among kidney transplant recipients. The study randomizes people to either receive standard immunosuppressants or this cellular therapy and fewer immunosuppressants. It only includes kidney transplant recipients receiving organs from live donors so transplant surgery timing won't hinge on the unpredictable schedule of performing surgery and follow-up care when a donor dies.

Neglected tropical diseases affect more people than the population of Europe

This group of conditions, which includes hookworm, sickens roughly one in seven people on the planet—a tally which dwarfs Europe's population of roughly 450 million. International cooperation and donations are helping to control some of these illnesses, which can be caused by parasites, viruses, and bacteria. They're all treatable or preventable, but primarily occur among poor, isolated communities that may not receive adequate care.

Learn how cholera bacteria sicken humans

Once a person has ingested large amounts of the bacteria, typically through contaminated water, cholera bacteria begin producing and releasing a toxin inside their host. It attacks the mucosal lining of the intestine, making it hard to absorb liquids. This process leads to cholera's characteristic symptoms, like voluminous, watery diarrhea.

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.

Although rare, HFMD can spreads in pools due to poor bathroom hygiene

In pools with inadequate levels of chlorine, this disease can spread via the poop-to-mouth route, though this isn't one of the most common ways the disease is transmitted. People can become infected by swallowing contaminated pool water after little kids (or their parents) don't do an adequate job removing virus-laden feces from the child before the child enters the water.

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

Gastroenterologist Dr. Ugo Iroku answers the internet’s burning questions about digestion and bowel movements. Get the lowdown on what it means when your stuff is super dark, the impact of coffee on evacuating bowels, and much more.

Western babies often are missing a key gut microbe common elsewhere

Studies show infants in Europe and North America often lack Bifidobacterium infantis, a microbe widespread in babies in Africa and South Asia that helps digest breast milk and train the immune system. Researchers link the gap to antibiotics, formula use, and sanitized spaces.

How heart transplants work

Heart transplants require an old heart to be removed and a new one to be installed without killing the patient. How does that work? In this easy-to-understand five-minute video, learn each step of the intricate process, from donor matching to the preservative solution a heart is doused in while it is transported.

View a breakdown of bioremediation strategies, divided into onsite and offsite options

Depending on the contamination's complexity, in situ—onsite—options may be preferred and can include supplying oxygen or nutrients into the existing soil to accelerate the microbial breakdown already present in the environment. Ex-situ methods instead displace contamination for treatment away from the environment and may be used for volatile chemicals that require isolation, though this displacement can also spread contaminants if spilled.

How scientists are using molecules found in acidophiles to develop new medical treatments

The Berkeley Pit, an open-pit copper mine in Butte, Montana, that ceased operations in 1982 and is now filled with highly acidic water, is home to various species of fungi and yeast. These extremophiles produce unique compounds that may have anti-inflammatory benefits and have already been used to create an antibiotic for staph infections.

You can sign up to donate your body to science

It's a separate process to donate your body for medical research; you usually must contact a whole-body donation program directly. Bodies can be donated for medical research, for forensic analysis research, or for medical students to work with as they learn anatomy and surgery, among other purposes. Learn more about numerous accredited organizations that provide human bodies, organs, and tissues to medical researchers and students.

Supplements ahead of exertional heatstroke helped protect mice against brain damage

In the lab, mice dosed with probiotics prior to inducing exertional heatstroke, had better cognitive outcomes. This evidence underscores the links between the gut microbiome and the brain, at least in rodents.

Model organisms like yeast, mice, and flies help scientists decode the human body

Some species are used to quickly study the effects of human diseases and treatments because they are short-lived and have similar systems to those found in humans. Bacteria, like E. coli, have been used as human proxies given their rapid growth and ease of genetic manipulability.

Gene therapy treats a disease by editing its DNA source

This modification is typically performed by viruses, which are naturally skilled at entering cells but have their disease-causing component removed before delivery. Once inside, cells can use the inserted genetic material to produce more helpful proteins, fewer harmful ones, or create new proteins.

Living donations most commonly involve a kidney or part of a liver

In 2023, more than 6,900 transplants were made possible thanks to living donors. Living donation is when a living person donates an organ or part of an organ—usually one of their two kidneys or part of the liver, since that organ can regenerate in a healthy person. Much more rarely, living donors donate other organs. Living donations often occur when someone wants to ensure a loved one has certainty that they will quickly receive a needed organ.

When was the first blood transfusion?

In the 1600s, an English doctor transferred the blood from one dog to another via quills. The procedure ended when one of the dogs died. This article details the early days of blood transfusions, which turned toward humans shortly after the 1666 dog experiment and involved putting the blood of a sheep into a human recipient (who reportedly survived the encounter).

Oral rehydration solution was developed in the 1960s in response to cholera deaths

Drinking this life-saving mix, which consists of clean water, salts, and sugar, helps the human body rehydrate after extreme bouts of diarrhea, vomiting, or both. It's now used for a variety of diarrheal diseases.

Odor blockers use nonpolar oils to trap smelly polar molecules

In the case of feces, gut bacteria produce compounds such as skatole and hydrogen sulfide, which the brain registers as unpleasant. Because oils do not dissolve in water, they can be used to create a layer on the surface that prevents smelly compounds underwater from escaping into the air.

'Human composting' is an eco-friendly burial method legal in only a few states

Formally known as natural human organ reduction, this process relies on the same principles as standard composting and breaks down the body over many weeks, turning it into a type of soil. It's currently only legal in a handful of states.

Microbial research suggests shifts in diverse populations may help an invasive species establish itself

In 1958, English ecologist Charles Elton suggested that diverse ecosystems should be more resistant to invasive species because gaining a foothold would be more challenging when resources are more thinly spread. However, in lab-grown microbial ecosystems with greater biodiversity, population volatility opened more ecological roles that invasive species could easily fill.

Most people breathe fungal spores daily without getting sick

Most people breathe in hundreds of Aspergillus fumigatus spores daily without getting sick—it’s a common microscopic fungus in our environment. But people who are severely ill, including those who have undergone an organ transplant, are at risk of developing infections from these spores.

Watch students comically portray how plants can detoxify the environment

Through a series of processes that collectively make up phytoremediation, plants can take up pollutants from soil and water through their roots, then break them down, release them as less harmful gases, or store them within their cells. Any plants that sequester heavy metals or other toxins must be removed and managed after the environment is decontaminated.

Candida albicans is a natural body-dwelling yeast, but it can cause yeast infections

This fungus is naturally occurring on the body, but C. albicans can become a problem when the natural balance of bacteria on the body is off-kilter, allowing this yeast to spread. It can cause anything from diaper rash to a yeast infection in the throat or vagina. It’s typically treated with doctor-prescribed antifungal medications.

NSF-funded research into matching algorithms improved the success of organ transplants

Investigations in game theory, including concepts focused on creating mutually beneficial partnerships—matching theory—led to the design of computer systems that efficiently matched kidney recipients and live donors, resulting in higher-quality matches. By 2019, these matching algorithms were used for multi-organ exchanges.

The cholera bacteria was first isolated in 1854—but the discovery was largely ignored

The pathogen was isolated by the Italian physician Filippo Pacini in Florence, Italy, though his discovery was largely ignored in favor of the popular miasma—bad air—theory of disease at the time. The pathogen was separately isolated about three decades later by German microbiologist Robert Koch.

What conditions can be treated with stem cells?

Stem cell research is a global enterprise, and much of the work is being done in Europe. This page gives readers a good sense of the medical conditions stem cell researchers in Europe focus on, and the specific research challenges they address. This page also offers links to in-depth information about many of the research projects.

Teaching immune cells to fight cancer

CAR T-cell therapy is a type of immunotherapy, which involves strengthening the immune system to attack cancer cells. Patient T cells, which manage immune responses and are responsible for killing pathogen-infected cells, are collected and re-engineered to produce surface-level proteins called chimeric antigen receptors. These CARs, now able to bind to specific proteins on cancer cell surfaces, are multiplied into the millions and infused back into the patient.

Artificial sweeteners may disrupt gut health

Some research suggests that certain sweeteners can throw off the balance of beneficial bacteria in the gut and shift the composition of the microbiome. Such changes, depending on an individual's specific gut flora and levels of sweetener consumption, could potentially affect metabolism and glucose tolerance or lead to bloating and diarrhea.

Mitochondrial DNA swapping can occur before or after fertilization

Mitochondrial replacement therapy can be conducted with four different techniques, with varying genetic material transferred depending on the approach. Maternal spindle transfer, one common method, involves transplanting the nuclear DNA from a mother into an unfertilized egg from a donor. The donor egg is then fertilized and implanted into the mother's uterus using in vitro fertilization. Another major approach, pronuclear transfer, does the genetic swapping after the mother's egg has already been fertilized. This order of operations may be uncomfortable for some individuals, but the success rate with this technique is higher.

Women's wartime suit features silk dyed with CRISPR-modified bacteria

Anna Dumitriu's bioart piece was created to commemorate the 75th anniversary of the first use of penicillin in a human patient and intends to raise awareness about the rapid development of antibiotic-resistant pathogens by using bacteria that have essentially been transformed into their pre-antibiotic era state.

Open brain surgery is not required for BCIs inserted via blood vessel injection

Synchron's brain-computer interface, the Synchron Switch, takes advantage of preexisting medical devices, such as stents and catheters. Cells grow over the device over a 90-day period, incorporating it into the vessel wall and minimizing clots.