The ketogenic diet is similar to other reduced-carb diets used for gut issues, and creates specific molecules similar to short-chain fatty acid.
Josh Nock suffered for years from nauseating pain and unpredictable bowel movements caused by irritable bowel syndrome (IBS) that didn’t ease up with doctor-recommended medication or a high-fiber diet.
While attending a health seminar, Mr. Nock, a personal trainer, learned that a ketogenic diet could help improve gut symptoms. In desperation, he committed to a 30-day keto challenge in January.
The first two weeks were horrible, and Mr. Nock told The Epoch Times he nearly gave up. But he pushed through symptoms sometimes called “keto flu,” a condition of headaches, nausea, fatigue, constipation, and more. Ultimately, his IBS stopped aggravating him—and he experienced other benefits he wasn’t counting on.
“The main thing is I don’t go to the toilet nearly as much as I used to, and no bloat anymore,” Mr. Nock said. “I was only going to do it for a month, but I feel so good I’ve just carried it on.”
Registered dietitian Tamzyn Murphy explained that a ketogenic diet is well-known for being anti-inflammatory, much like other diets that restrict carbohydrate intake. Keto diets are intentionally high in fat and sometimes protein, used to switch the body’s metabolic state from burning carbs to burning fat for energy.
Many other diets for gut issues are low in carbs, such as specific carbohydrate and low-FODMAP diets. FODMAP refers to hard-to-digest carbohydrates—fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. By limiting total carbohydrate intake, ketogenic diets logically have a similar efficacy, Ms. Murphy told The Epoch Times.
Related Stories
Defining a Keto Diet
Studies on ketogenic diets are lacking and sometimes flawed, argued a 2021 Human Microbiome review. The authors point to evidence that, when done correctly, ketogenic diets may be a healthy alternative to the predominant advice to eat a diet of diverse plants to heal poor gut health.
Although keto diets are not medically recommended for IBS or other gut disorders the review outlines evidence that the diet may reduce gut permeability, regulate immune system function, increase mucosal production, and create the same short-chain fatty acid proven valuable for gut health in plant-based diets.
The authors tackle the dual notions driving criticism of ketogenic diets—that fiber is not only beneficial but necessary, and animal fat is destructive to gut microbiota.
One complication of keto diet research is how high-fat diets are defined. According to the review, in animal studies particularly, low-carb diets are often low in fiber and contain refined sugar, soybean oil, and lard. In other words, they may more closely resemble the standard American diet, including being high in damaging ingredients, than a therapeutic ketogenic diet.
“No wonder people get confused—because they’re two different things they’re trying to make one and the same,” organic farmer and environmental scientist Alison Gannett told The Epoch Times.
Ms. Gannett prefers the term therapeutic carb reduction because keto has unlimited definitions. She eats nine cups of vegetables a day—other keto diets might be more carnivore in nature. In her opinion, a custom-designed diet with a breadth of high-quality, low-carb options should be distinguished from the popularized keto diet for weight loss that’s typically high in red meat and cheeses.
Ms. Gannett is the owner of Personalized Anticancer Nutrition, which tests clients’ unique DNA and microbiome to personalize eating plans that will keep them in a fat-burning state. The microbiome is measured using stool samples that check the abundance of various bacteria, viruses, fungi, and other microorganisms in the colon.
Ms. Murphy said instead of learning more about the metabolic role of foods, many people who already eat a lot of bread, rice, and pasta start a keto diet by getting low-carb alternatives rather than looking for alternative whole foods naturally low in carbohydrates.
“The biggest mistake on a ketogenic diet is taking your preconceived ideas about diet before—when you ate processed foods—and trying to apply those to a ketogenic diet, instead of rethinking it in totality,” she said. “The problem is you’re going from one form of processed food to another form of processed food.”
It’s possible, Ms. Murphy noted, that people wouldn’t need to be exploring therapeutic diets if there wasn’t a chronic disease epidemic driven by overconsumption of ultra-processed foods high in refined carbs, sugar, and highly refined seed and vegetable oils.
An Option for GI Disease
Noting that the authors aren’t aware of studies specifically assessing the diet for gut barrier function, the Human Microbiome review spells out how ketogenic diets may be a “therapeutic option in certain patients with gastrointestinal diseases.”
- Keto diets increase beta-hydroxybutyrate, which may restrict the growth of certain beneficial gut bacteria but has also been shown to enhance intestinal function and reduce the permeability of the intestinal barrier and has been therapeutic in ulcerative colitis, a type of inflammatory bowel disease (IBD).
- Ketosis reduces Th17 cells in the small intestine, which maintain the gut barrier and clear out pathogenic microbes, but are also associated with inflammation and autoimmune diseases.
- Ketosis may support the gut mucus layer.
- Other molecules take the place of the short-chain fatty acid butyrate, which is produced on a diverse plant-based diet but not on a high-fat diet.
Butyrate is important because it helps to maintain gut barrier function and protect the body from toxins and an immune response that can lead to a variety of autoimmune diseases. Because the ketogenic diet is lower in fiber and diverse plants, there is less colon fermentation—the process that creates butyrate.
Fast-Changing Microbiota
Interestingly, both critics and proponents of ketogenic diets often point to the same study to prop up their arguments. Published in Nature in 2014, the study noted how quickly the gut microbiota are able to adapt when the diet changes from plant-based to an animal-based diet.
In the study, six men and four women followed a plant-based diet exclusively for five days and then a mostly animal-based diet for five days, with microbiome monitoring before and after each session. Both diets permitted pathogenic bacteria to enter the gut. Both diets were also shown to produce butyrate, with the animal-based diet resulting in significantly higher levels of isobutyrate.
The authors noted that the animal-based diet increased the amount of Bilophila wadsworthia, known to trigger IBD.
In his book “Fiber Fueled,” Dr. Will Bulsiewicz highlights this study as a reason to avoid carbohydrate-restricted diets, with his take being, “It’s alarming to consider that in less than five days the foundation is being laid for the development of Crohn’s disease or ulcerative colitis with this diet.”
He writes that losing weight and looking good isn’t necessarily associated with being healthy—that people can be “rotting on the inside. It’s short-term gain and long-term pain. Do you know the average life expectancy of a professional bodybuilder? It’s just forty-seven years. Weight loss doesn’t always translate into better health.”
Still, the authors of the Human Microbiome review noted that the sometimes contradictory findings of how keto diets affect the gut warrant more inspection, “The most interesting and perhaps contentious finding was that there was no significant change in alpha-diversity in either group … While often cited as evidence that an animal-based diet is harmful, this is far from conclusive.”
The Choice to Live
Ms. Gannett agrees that weight loss itself doesn’t equate with health. However, she’s a proponent of carbohydrate restriction—when done correctly—and it’s personal for her.
She was a world champion extreme skier when she underwent extensive testing in 2013 and discovered she had the gut microbiome of an “overweight, unathletic woman with diabetes”—and she’d just been diagnosed with a terminal brain tumor that gave her an average life expectancy of just over six months.
However, Ms. Gannett was determined to make radical changes as necessary to beat the odds and has spent the past decade thriving as a result. Starving the cancer by switching her metabolism from digesting carbs (glycolysis) to digesting fat (ketosis) has been so transformative in stopping her tumor growth that Ms. Gannett became a coach to help others with testing and personalized diets within the ketogenic framework.
“I wanted to live, so I decided I was going to take the approach and find the people who would support me in finding the root causes of my cancer. I got so addicted with putting the pieces of the puzzle together, and it gave me so much inspiration and so much hope that I wanted to do that for other people,” she said. “I feel better at age 59 than I did in my 20s.”
