Exploring the Link Between Anorexia and the Microbiome
If you’ve ever heard the phrase “trust your gut,” you probably didn’t imagine it meant trusting billions of tiny bacteria inside your intestines. This begs the question: can gut bacteria mess with body image? But here’s the wild part—those microscopic microbes might be doing more than helping you digest food. They might also influence your thoughts, feelings, and maybe even how you see yourself. That’s right—some scientists are exploring whether gut bacteria could play a role in how anorexia nervosa (AN) warps body image and keeps people stuck in a cycle of restriction and fear.
Let’s break down “can gut bacteria mess with body image?” together.
1. The Gut-Brain Superhighway
Imagine a fast-moving highway that runs between your brain and your gut. That’s the gut-brain axis, constantly buzzing with signals via nerves, hormones, and even immune system messengers. Your gut microbiome – the trillions of bacteria living inside your digestive tract – are basically passengers on that road trip, sending messages that can affect your mood, appetite, and maybe even your sense of self.
So when people say the gut is the “second brain,” they’re not exaggerating. Science now shows that your gut has a huge say in how you feel emotionally. But could it also affect how you feel about your body? And be a possible way to see if the question “can gut bacteria mess with body image?” is true or not.
2. What’s Different in the Guts of People With Anorexia?
It turns out that people with anorexia have very different gut bacteria compared to those without the disorder. A big 2024 study published in Nature Microbiology found that several types of helpful bacteria—especially from the Clostridium group—were missing. These bacteria are usually involved in metabolism and helping the body process energy.
Instead, the guts of people with AN had more bacteriophages—viruses that infect bacteria—and fewer of the microbes that produce essential nutrients like thiamine (vitamin B1). This disruption might sound small, but over time, it can seriously affect how the body and brain work.
3. Can Gut Bacteria Affect the Mind?
Here’s where things get interesting—and a little spooky. Some of the bacteria found more often in people with anorexia have been linked with perfectionist tendencies, rigid thinking, and low self-esteem. That doesn’t mean the microbes cause these traits, but there’s definitely a pattern.
Gut bacteria also influence serotonin—the feel-good chemical that helps regulate mood. In fact, about 90% of the body’s serotonin is made in the gut. If that system gets thrown off, it could make emotional regulation harder and impact how someone judges their own body. Starving the body, which happens during anorexia, also starves the gut bacteria, creating a vicious loop that’s hard to break.
4. Hidden Chemicals That Mess With Hunger
Another way gut microbes might mess with things? Chemical sabotage. Also see
Some bacteria produce molecules that suppress hunger or interfere with the body’s fullness signals. One of these is called indole-3-propionic acid, which seems to lower appetite. Others mess with hormones like leptin (which tells your brain you’re full), or hijack tryptophan, a building block of serotonin.
Basically, the more your gut microbes get thrown off by under-eating, the more they start producing stuff that keeps you stuck in under-eating. It’s a chemical tug-of-war, and the bacteria might be pulling on the rope. Also see:
5. Mouse Studies Offer Clues
You might be wondering—how do we even know gut bacteria can influence eating habits?
In a landmark 2023 study, researchers took gut bacteria from patients with anorexia and transplanted them into germ-free mice. The results were startling: the mice started eating less and burning more energy. Some of their brain genes involved in appetite suppression lit up as if they’d been rewired.
Of course, mice aren’t people, but the study showed that gut microbes can directly change eating behaviour—without any emotional trauma or external pressures involved. That’s a pretty big deal.
6. Could This Explain Body Image Distortion?
So, do gut microbes literally make people see themselves differently in the mirror?
We’re not there yet. No study has proven that gut bacteria distort body image—but there are some compelling clues. For instance, the gut is deeply tied to interoception, which is your ability to sense what’s happening inside your body (like hunger, fullness, or heartbeat). If that system is off, it might affect how you interpret signals from your own body.
Add to that altered serotonin pathways, mood disturbances, and chronic malnutrition from AN—and you’ve got a brain that might be processing self-image through a very distorted lens.
7. The Chicken-or-Egg Question
One big question still hangs in the air: does anorexia cause changes in gut bacteria, or do weird gut bacteria help cause anorexia?
The answer is probably a bit of both. Starvation definitely alters the microbiome, but some people may have gut issues that predispose them to restrictive eating. In this feedback loop, the more someone restricts, the worse the gut imbalance becomes—and the more it fuels restrictive behaviors.
It’s complicated, but the important takeaway is that it’s not all in your head. There’s a body-brain-bacteria loop at work here.
8. Hope on the Horizon: Microbiome Therapy
Here’s the hopeful part. Researchers are now testing ways to fix the gut-brain imbalance in AN.
Some early studies show that certain probiotics—like Lactobacillus strains—might help people regain weight and reduce anxiety. Fecal transplants (yes, poop transplants) are also being explored to reset the gut microbiome. And supplements like vitamin B1 and omega-3 fatty acids may help support a healthier gut ecosystem.
We’re still early in this journey, but the idea that healing the gut could help heal the mind is incredibly promising.
9. What You Can Do Right Now
Even if you’re not in a lab or clinical trial, there are some gut-friendly things you can start doing today:
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Eat a variety of plant-based foods: fibre feeds the good bacteria
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Lower your stress: Solution-focused hypnotherapy, Meditation and mindfulness help gut-brain communication
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Avoid unnecessary antibiotics: they can wipe out helpful microbes
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Keep track: notice how certain foods or habits affect your mood or self-image
And most importantly, don’t go through this alone. Whether you’re struggling with anorexia, body image, or just feeling out of sync, reach out for help. Nutritional psychiatry (yes, it’s a thing!) is growing, and some professionals understand how food, mood, and microbes connect.
The Takeaway of the question: can gut bacteria mess with body image?
The gut-brain connection isn’t just trendy wellness talk, it’s real science. And while we still can’t say that gut bacteria directly cause anorexia or body image issues, the evidence is piling up that they play a bigger role than we ever imagined.
So next time you hear someone say “it’s all in your head,” remember: your head and your gut are on the same team—and sometimes, healing starts from the inside out.