A woman gave herself poop transplants using her brother’s feces to treat debilitating IBS. Then she started getting acne just like him.

FMTs are only approved by the US Food and Drug Administration for C diff. bacterial infections, but scientists are looking into them as a potential treatment for many conditions, including depression, as growing research suggests there is a link between gut health and mental and physical health conditions.

While some of Koepke’s symptoms got better, she said she also started experiencing acne like her brother, and later depression like her boyfriend.

A similar experience was documented in the 2023 documentary “Designer $hit.” A man in his mid-30s with Crohn’s disease did DIY poop transplants using his mom as a donor for years. They appeared to ease his gut symptoms, but he experienced menopause symptoms such as sweating, hot flashes, and mood swings, similar to his menopausal mom.

Thomas Borody, the director of the Centre for Digestive Diseases in Sydney, Australia, who pioneered FMT treatments in the 1980s, told “Designer $hit” that it’s possible the man absorbed hormones from her poop, but that link has not been proven.

Cutting food out of her diet made things worse

Koepke’s gut symptoms, which she believes were the result of a diet high in refined sugar and low in fiber, didn’t fit neatly into a box. Doctors were at a loss for what to do, so they prescribed antibiotics “like candy,” she said.

Over the past five years, she had taken six courses of antibiotics a year. But they didn’t help. Studies have found that antibiotics can kill off good bacteria in the gut.

As she got sicker, Koepke cut more and more foods out of her diet, as they were inflaming her symptoms, and she lost a lot of weight. Now, she can only eat between 10 and 15 foods without discomfort.

“It’s really hard for me to remember what it was like to eat food before it became associated with anxiety and pain and discomfort,” she said.

Guilia Enders, a medical doctor who’s written a book on the gut, told the documentary: “If we cut foods out of our diet, we’ll change our microbes drastically. Because who can live there if you don’t feed them?”

The gut microbiome is made up of trillions of microbes that live in the colon lining. They feed off of the food we eat, but different foods feed different microbes.

Later, if a person tries to reintroduce certain foods to their diet, they might get symptoms such as bloating and stomach pain, Enders said. Dietary fiber is particularly important for gut health as it feeds the good microbes, but intake needs to be built up gradually, she said.

As Koepke can’t tolerate a lot of nutritious foods, she takes supplements to try to get the nutrients her body needs but said she feels deprived by her limited diet. She said she needs to repopulate her gut with healthy bacteria by eating a diverse range of plant foods, but that makes her symptoms flare up.

Koepke turned to poop transplants because she felt there were no other options

An FMT starts with blending a healthy donor’s feces with saline solution and inserting it into the recipient’s gastrointestinal tract, either through an enema, oral capsules, colonoscopy, or upper endoscopy.

Experts in the documentary warned against trying poop transplants at home because there is a risk of transferring bad microbes and susceptibility to all kinds of diseases.

“The microbial community inside our gut can have surprising influences on different parts of our body,” Jack Gilbert, a microbial ecologist at UC San Diego, told Business Insider. Stools are screened before clinical FMTs, and anything that could cause major problems, such as certain pathogens, would be detected, he said. When you do this at home, you don’t get that kind of screening.

“With fecal microbiome transplants, there is really compelling evidence, but the science is still developing. We’re still working on if it actually has benefits for wider populations and if the benefit is long-lasting,” Gilbert, told the documentary.

She got acne like her brother and depression like her boyfriend after FMTs

Initially, Koepke made fecal transplant pills from her brother’s donated stools. She slowly started to gain weight despite not changing her diet and was able to go to the bathroom naturally for the first time in three years.

However, she also developed acne, like her brother, who had a history of hormonal acne.

It’s possible that the bacteria in the stool can influence inflammation in the recipient’s body, by affecting their metabolism and activating their immune response, Gilbert told BI. This would cause shifts in their hormonal activity, which could promote the bacteria that can cause acne on the skin.

“We nearly all have this bacterium on skin, but it is often dormant,” he said.

Koepke decided to switch donors and, for a few months, used her boyfriend’s poop for the fecal transplants, who had no physical health problems but did experience depression. After she made the switch, her acne went away, but this time, she experienced depression symptoms.

“Over time, I realized my depression was worse than it’s ever been in my life,” she said. Koepke believes whatever microbes were playing a role in his depression were transplanted into her.

When Koepke once again switched back to her brother’s poop transplants, the depression went away within a week, she said.

Gilbert said that according to his research, people with depression are missing certain bacteria from their gut. “She may have had the ‘anti-depressant’ bacteria in her gut, but when she swapped her microbiome with his, her anti-depressant bacteria got wiped out,” he said.