What Is The Effect Of A Keto Diet On The Gut—Besides Six-Pack Abs?
Eating an ultra low-carb keto diet can help you easily burn unwanted stored bodyfat. Interested in giving a keto a try? If you are, keep in mind that you must be prepared to suffer a few days of “keto flu.” These flu-like symptoms occur when you switch from primarily burning carbs to healthy fats. Get over that hump and in just a short time, you can dramatically change your body composition.
But beyond aesthetic improvements, does a keto diet improve your gut health? Do the trillions of cells and thousands of bacterial species residing in your gut like it when you largely deprive your body of carbs?
Several research studies in just the last few years have explored these questions. Let’s dive in and take a look.
Keto, Gut Health & Epilepsy
The ketogenic diet was formulated approximately a century ago. It’s initial function was to serve as a medically-supervised diet for those suffering from seizures caused by the neurological disorder, epilepsy. A 2018 study explored the role a very low carb diet plays not only in lowering seizures but also on the microorganisms in the gut.
The study found that within four days of being on a keto diet, the experimental mice underwent significant changes in the number of different microbes in the gut. The two species of friendly bacteria that increased the most were Akkermansia and Parabacteroides. The former was described in a research paper last year as “a promising candidate as probiotics [which] is known to [improve] the host metabolic functions and immune responses.”
Bacteroides, meanwhile, account for about one-third of all the microscopic organisms in your gut. That makes these all-you-can-eat freeloaders the most predominant species of bacteria in your GI tract. Although some of them are disease-causing pathogens, they are essential members of a balanced microbiota; they play an essential role in fortifying the lining of the gut and lower inflammation.
Another recent study on a small number of people investigated the same link between epilepsy, a keto diet and gut health. Those with epilepsy demonstrated an imbalance of gut microbiota before embarking on a keto diet. The researchers found that the subjects with epilepsy had more pathogenic bacteria—Escherichia, Salmonella and Vibrio.
Guess what happened after the subjects with epilepsy switched to a keto diet (medically supervised, of course). Remember Bacteroidetes that was just mentioned? The number of bacteria from this species increased. Bacteroides help break down fats and regulate the secretion of pro-inflammatory cells called interleukins. These cells are what trigger seizures. The researchers suggest that a keto diet can reduce seizures by changing the diversity of gut bacteria.
Keto, Gut Health & Alzheimer’s
A 16-week study from 2018 demonstrated that mice who were fed a very low carb diet experienced significant neurovascular improvement. This improvement of blood flow to the nerves and through the blood vessels are associated with a lower risk of developing Alzheimer’s disease.
Again, the main reason for the improvement, the researchers speculated, is because of the improvement in gut microorganism composition. The two strains that were improved the most were Akkermansia Muciniphila—the same strain that was improved in the human epilepsy study—and Lactobacillus.
Lactobacillus, a common type of (mostly) friendly bacteria, produce lactic acid, which helps to keep harmful bacteria at bay. The study also showed that the mice fed a low-carb diet had less pro-inflammatory microbes such as the aforementioned vibrio as well as Turicibacter.
Keto, Gut Health & Autism
A 2016 study investigated whether or not a very low carb diet offered any benefits on gut health in regards to autism spectrum disorder. Now it’s important to note that this study was performed on mice, not people.
The researchers fed the mice a low carb diet for up to 14 days. What the researchers discovered was a paradox. On one hand, the low carb diet decreased the overall diversity of bacteria in the lower GI tract. But it also improved the ratio of Firmicutes to Bacteroides species. A low ratio of these two species is common in autism spectrum disorder. By improving this ratio, an improvement in behavioral symptoms in the experimental mice was observed.
Keto, Gut Health & Multiple Sclerosis
Researchers in 2017 showed a keto diet could improve multiple sclerosis (MS) symptoms. What the researchers discovered was that a very low carb diet completely restored the bacteria that ferments in the colon. This in turn provides bacteria in the colon with prebiotic fiber, which fertilizes the bacteria.
Gut Diversity On a Keto Diet
Similar to the autism study, the researchers in the MS study found that a very low carb diet decreases the diversity of gut bacteria. Doesn’t that sound like a bad thing? It could be. But it depends what kind of carbs you eat, even if you’re severely restricting the carb count.
If you’re eating a keto diet, make sure you’re eating foods like Miracle Noodle that are resistant to digestion in the small intestine (resistant starches).
But for anybody tackling gut health/inflammatory conditions, trying a ketogenic diet may prove that it’s worth having less gut diversity. Especially if the number of harmful, pathogenic bacteria is lowered.