Can the gut microbiome drive addiction?

Gut microbiome experiments involving transfers of gut microbes from depressed people to rodents indicate that the rodents may then display depression-like symptoms.

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.

The reason some people love exercise may be because of their microbiome

Certain gut microbes in mice trigger dopamine release and drive motivation to exercise more. Scientists are investigating whether humans carry similar microbial patterns that influence our natural inclination towards movement, exploring how unseen microbial ecosystems may shape mammalian fitness behavior and reinforce innate reward pathways. (Some users may experience a paywall.)

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 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.

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.

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.

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.

Researchers are investigating how altering the gut microbiome may influence the development of rheumatoid arthritis, which is an autoimmune disease.

Chronic drug use can cause neurological changes in the brain

Neuroscientist Judy Grisel breaks down the biology of addiction, examining how drugs hijack the brain’s natural reward system and create lasting neural changes. The physiological and neurological impacts of chronic drug use require a multifaceted treatment approach.

Addictive drugs can cause dopamine levels to become ten times higher than normal.

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

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

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

Addiction develops when the pleasure circuits in the brain get overwhelmed

Normal pleasure circuits become overwhelmed by addictive substances, triggering dopamine floods many times stronger than those induced by everyday reward experiences. The understanding of addiction as a brain disease has led to treatments pairing medication and counseling.

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.

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

GLP-1 drugs are under investigation for treating Alzheimer's, Parkinson's, and drug addiction

Researchers are investigating GLP-1 applications for a variety of chronic conditions. One area of interest stems from how study participants using GLP-1 for diabetes and obesity reported describing less longing for wine and cigarettes while taking the medication—intriguing researchers about using the drugs for addiction applications. The drug, they theorize, could bind to receptors that mediate desire. (Some users may experience a paywall.)

Addiction is defined as chronic compulsive drug use despite adverse consequences

This resource from the National Institute on Drug Abuse provides a comprehensive look at addiction as a complex brain disorder. It explores why people initially take addictive substances and how continued use alters the brain’s reward system.

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.

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.

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.

Some dementia cases may be linked to treatable microorganism infections in the brain.

Drug tolerance and withdrawals are consequences of overloading dopamine circuits

Addictive substances or behaviors will typically flood our brains with more dopamine than usual. In response to the overstimulation, our brains will decrease the number of available dopamine receptors. This results in the need for more stimulus for the same response (tolerance) and a rise in negative feelings when the stimulus is absent (withdrawal).

Exercise causes diet-independent changes in the gut microbiome.

'Susan's Brain': what happens to the brain during addiction

This engaging animation from Harvard Online breaks down the neuroscience of addiction through the story of “Susan’s brain,” demonstrating how addictive substances hijack normal reward pathways. Through clear visual metaphors and approachable narration, it explains complex brain chemistry in understandable terms.

'The opposite of addiction isn't sobriety—it's human connection'

This thought-provoking TED talk from journalist Johann Hari challenges conventional wisdom about addiction, with a special focus on his global research investigating its root causes. Through personal stories and scientific evidence, Hari debunks some of the most common myths around addiction.

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

The body produces its own opioids that act on several receptor types throughout the body, triggering the release of dopamine and suppression of noradrenaline, neurotransmitters associated with reward and alertness, respectively.

The science of addiction treatment

A helpful resource from the National Institute on Drug Abuse (part of the NIH). This article examines addiction treatment and recovery through the science behind several accepted methods. The guide draws helpful comparisons with other chronic disease treatments. In particular, it discusses the overlap between medications and therapeutic treatments, and the understanding that relapse doesn’t indicate treatment failure—only a need for continued or modified care.

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.

Why processed foods can be so addictive

In recent years, many critics have voiced their concerns about the food industry and how ultra-processed foods affect our health. Despite our awareness of these issues, processed foods are still incredibly hard to remove from our diet. In this podcast by The Guardian, Dr. Chris van Tulleken explains how “junk food” is created to get us hooked, how it negatively affects us, and what we can do to improve our eating habits.

Neural replays in mice help explain food aversions

Princeton University scientists published research in 2025 analyzing how mice learn to associate certain foods or flavors with feeling ill—even when there’s a time gap between eating something and feeling sick. The work, performed with grape Kool-Aid and injections of a substance that made mice sick, traced the literal “gut reaction” of how gut distress signals are linked to neural replays of what the mouse ate.

Some research suggests that the gut microbiome influences our risk of heatstroke, with elevated exercise levels raising body temperature to unsafe levels and increasing gut permeability—causing a "leaky" gut.

Psychedelics set off a flurry of brain activity that may permanently alter it

The brain seems to experience a sharp increase in communication between areas that generally don't interact. New research suggests a thin, sheet-like gray matter structure tucked deep within the brain, between the insular cortex and striatum, may be the key to this change. The area is centrally located and home to many of the receptors that psychedelics target, potentially rewiring the brain and rewriting thought patterns.

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.

Why the human brain loves opioids

When opioids enter the brain, they dock in receptors, blocking electrical pulses such as those that communicate pain. They also trigger the release of dopamine, a neurotransmitter tied to motivation and associated with stress relief.

Artificial sweeteners may disrupt gut health, throwing off the balance of beneficial bacteria in the gut and shifting the composition of the microbiome.

Fame can trigger addictive, drug-like highs in the brain

Differences in the type of fame, such as movie stardom, sports, and internet virality, can produce varying degrees of dependence on individuals based on their age and background. Some individuals—particularly children—can develop drug-seeking behavior as they pursue continuous dopamine spikes if they lack an existing sense of fulfillment from elsewhere.

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.

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.

These areas of the brain are hard-hit in depression—but the changes are reversible

Depressed brains can have certain characteristic changes, including an overactive amygdala, reduced hippocampus size, and changes to the thalamus and neuromodulating chemicals in the brain.

Social media addiction, though not a clinical diagnosis, refers to the idea that infinite scroll, notifications, and algorithms override one's ability to stop using them.

Move over gene editing, scientists can edit your epigenome

Instead of deleting genes, epigenetic editing modulates their activity. A new paper tests if it’s able to undo a genetic effect of early alcohol exposure.

Scientists identify hundreds of genes responsible for OCD

Researchers analyzed the DNA of more than 53,000 people with OCD and identified 30 areas in the genome linked to the disease, containing 249 genes of interest. Of those, several were linked to other brain disorders, paving the way for genetic treatments of various mental illnesses.

How alcohol rewires your brain

Alcohol doesn't just make you tipsy—it rewires your brain chemistry in real time. It slows your brain with GABA, spikes dopamine to make you feel unstoppable, and blocks glutamate so you can't form memories. That mix explains everything from slurred speech to blackouts … and brutal hangovers.

Autoimmune disease prevalence and incidence are on the rise—but no one knows why

Researchers theorize that environmental factors, including shifts to less healthy diets, air pollution, infections, stress, climate change, and exposures to xenobiotics—substances like pesticides, plastics, and toxins that incite immune responses—may all be fueling epigenetic changes to our bodies that make people's immune responses go awry.

Can microdosing improve mental health?

Animal studies involving microdoses of psilocybin, the psychoactive component in magic mushrooms and ketamine, found it helped to alleviate anxiety and inflammation, an immune response that can cause damage when chronically active. Human studies are ongoing. In at least one double-blind study, where researchers and patients don't know who got a placebo versus the real thing, about half of the participants incorrectly guessed they had been given placebos.

Fake sugars may disrupt metabolic health.