6 Cool Gut-Related Case Studies

Get our “getting started” mini-course:

Colored gut

Case studies are reports about what happened to one particular patient. They’re the lowest tier of medical evidence – no control group, no deliberate study design, no blinding or randomization. You can’t make a claim about people in general and then cite a case study to back it up – the one person in that case study might just have been a weirdo outlier, or had some particular unique circumstance.

But with that said, case studies are really interesting – they’re basically like professionally-described self experiments. It’s neat to get that much detail about something that worked (or didn’t work) for a complicated problem.

So here are 6 case reports about some interesting gut-related problems and solutions, from constipation to weight loss in diabetics.

1. Gut Hormones Help a Morbidly Obese Woman With Diabetes Lose 45 Pounds

The woman in this study was 38 years old, and had a pretty rocky health history: high blood pressure for years, trouble breathing, and extremely high blood sugar. She weighed 374 pounds.

The doctors recommended bariatric surgery, but first she had to lose some weight to reduce the potential for complications. The doctors put her on a diet and gave her metformin and another type of drug that increases production of Glucagon-like Peptide-1 (GLP-1). GLP-1 is a hormone produced in the gut, and stimulates the body’s production of insulin in response to carbohydrates and reduce appetite and food intake.

Most patients with diabetes who get put on GLP-1 agonists lose weight, and actually tend to keep it off in the medium-term (2-year follow-up). This woman had a fantastic response to the drug (21.2 kilograms, or 46.6 pounds) and kept it off for a year.

Gut hormones: more important for weight loss than you thought!

2. A Teenage Girl Develops Gut and Psychotic Symptoms From Gluten Exposure.

This case study is actually pretty scary. It’s the story of a perfectly normal 14-year old girl, who started having digestive problems and “severe headache, sleep problems, and behavior alterations, with several unmotivated crying spells and apathy.”

Then she started having vivid hallucinations:

The types of these hallucinations varied and were reported as indistinguishable from reality. The hallucinations involved vivid scenes either with family members (she heard her sister and her boyfriend having bad discussions) or without (she saw people coming off the television to follow and scare her), and hypnagogic hallucinations when she relaxed on her bed. She also presented weight loss (about 5% of her weight) and gastrointestinal symptoms such as abdominal distension and severe constipation.

She continued losing weight, and eventually her parents went to a nutritionist, who put the girl on a gluten-free diet for her digestive and weight-loss problems. Nobody expected the diet to affect the hallucinations at all, but it did. The doctors tested her with a blinded comparison of gluten flour and rice flour – the gluten brought all her hallucinations and digestive problems back, while the rice flour placebo had no effect.

It’s well-known that gut health affects mental health, but it’s rare for it to have such intense and dramatic effects!

3. Prebiotics + Antioxidants Make Metformin Better for One Man’s Blood Sugar Control

This case report describes a 30-year-old man with Type 2 Diabetes. One of the most common drugs for Type 2 Diabetes is metformin, which lowers blood sugar. But this man, like about 20% of the population, got diarrhea from the metformin. And he didn’t just get diarrhea; he also got pretty unimpressive results from the drug.

On the 9th day of his treatment, the researchers added a “cobiotic,” including inulin (a type of fiber), blueberry extract, and beta-glucan (another fiber). The goal of the cobiotic was to improve the man’s gut health with the combination of prebiotic fiber and antioxidants from the blueberries. His blood sugar immediately lowered and he started seeing much better results from the metformin. His diarrhea went away and his bowel movements normalized. After 8 weeks, he’d lost over 10 pounds and his blood sugar was down to 100mg/dl, the high end of normal.

This is just another example of how important the gut is for weight loss and blood sugar control.

4. Sympathomimetic Amines Cure a Teenager’s Treatment-Resistant Constipation.

The subject of this case study was an 18-year-old woman who had truly awful constipation: she had a bowel movement every 2-3 weeks. Ouch.

Then the doctor gave her 15 mg of dextroamphetamine sulfate, which belongs to a class of drugs called sympathomimetic amines. Sympathomimetic amines imitate the effects of the sympathetic nervous system (the “fight or flight” response).

The sympathomimetic amines cured the woman’s constipation almost immediately, and she’s apparently had normal bowel movements ever since. (And for the record, sympathomimetic amines can apparently do all kinds of other things, too, especially for women with inexplicable pelvic pain.)

This is more evidence for the theory of slow-transit constipation having something to do with the sympathetic nervous system in general. It also suggests that other central nervous system stimulants might be helpful for people with severe constipation. The drug used in this trial isn’t available over-the-counter because it has a high potential for abuse, but caffeine is a common and widely available stimulant drug that also affects the sympathetic nervous system.

5. Gut Flora Transplants Cure…Tons of Stuff

OK, this item is technically cheating a little, since it’s a bunch of different case reports that all go over one type of treatment. But to be fair, it’s a pretty impressive treatment! Fecal Microbiota Transplantation (FMT) is basically what it sounds like: transplanting the gut flora from the feces of a healthy person into a sick person’s colon. Yes, gross. But look at the benefits:

  • FMT is the hot new thing right now for treating Clostridium difficile, a notorious drug-resistant “superbug” that causes diarrhea and severe damage to the gut, and can eventually kill you if it’s not treated. This woman, age 49, had C. diff that kept coming back and didn’t respond to the antibiotic vancomycin, so she got a microbiota transplantation. Within 3 days, her diarrhea was gone and her symptoms resolved. The C. diff didn’t come back.
  • In this case report, FMT successfully treated septic shock and severe diarrhea in a 44-year-old woman after surgery.
  • In another case report, FMT was effective for chronic pouchitis (a type of intestinal infection that often occurs as a complication of Inflammatory Bowel Syndrome) in a 39-year-old man. The conclusion really says it all: “After 2 months of FMT, the patient’s stool frequency deceased from 20 to 5 times per day without urgency or rectal bleeding.” That gives an idea of just how dire the poor man’s situation was before the FMT, and how effectively the FMT cured it.

6. Antibiotics Control a Woman’s Treatment-Resistant Hypertension


Salt doesn’t cause high blood pressure…but gut dysfunction might, at least in this particular woman.

This case report discusses a 69-year-old woman with high blood pressure that didn’t respond to the usual antihypertensive drugs. While that was going on, she went into the hospital for an unrelated knee surgery. The wound became infected, and she got antibiotics for the infection.

To everyone’s surprise, the antibiotics were incredibly helpful for her blood pressure. For 2 weeks of antibiotic treatment, she was sitting around the low end of the healthy range (110 over 50-60) without any antihypertensive drugs at all. Her blood pressure was much better-controlled than usual for 6 months afterwards.

Most of us think of gut flora as being good for us, but it’s very possible that this woman was suffering from an overgrowth.

Case Studies =/= “Proof”

Again: none of these authors would claim that their conclusions apply to people in general. These are case studies, not randomized controlled double-blind clinical trials. They aren’t meant to draw conclusions about typical results; they’re just reporting an interesting or noteworthy thing that happened to one particular person.

But they’re still pretty neat to read about, and they do make you think about some problems that might be too out-there or too rare for doctors to do a big clinical study on.

Do any of the case studies sound like you? Let us know on Facebook or Twitter!

P.S. Have a look at Paleo Restart, our 30-day program. It has the tools to let you reset your body, lose weight and start feeling great.

+ Paleo Leap Tribe is now also available. Try out our meal plan generator and quick cheat sheets.

Get a PDF with our top 35 recipes