Intermittent Fasting and IBS

The gut microbiome disruption with IBS

There are many causes of irritable bowel syndrome (IBS), and what causes it for one person may not be the same for another. However, the one characteristic that all individuals with IBS have in common is a disruption in the gut microbiome. Whether this is due to stress, poor quality food (i.e., the standard American diet), or environmental toxins, all of these disrupt the balance of the gut microbiome, leading to an overgrowth of harmful bacteria and a decrease in good bacteria, causing typical symptoms like abdominal pain, bloating, constipation, diarrhea or(if you are lucky🤣) both. 

Intermittent Fasting Defined

Before delving into the benefits of intermittent fasting for IBS, let's first understand what it entails. Intermittent fasting is a dietary approach involving alternating fasting and eating periods. The fasting window can range from 12 to 72 hours, varying throughout the week. For instance, if you stop eating at 6 PM and resume meals the following day at 7 AM, you've completed a 13-hour fasting window. 

Our hunter-gatherer ancestors practiced intermittent fasting out of necessity for most of human existence.  It wasn’t until humans stopped the nomadic lifestyle and started farming(about 10,000 years ago) that the food supply became more predictable. Even then, the success or failure of a crop depends on weather, rainfall, soil quality, and other variables. It has only been over the last 60-70 years that we have an overabundance of food(sugar-filled, poor quality food-like substances) constantly available to us, any time of the day. We eat from the time we get up until we go to bed. Or, like many Americans who have poor quality sleep, they raid the refrigerator or freezer in the middle of the night, obliterating the fasting window.

The Benefits of Intermittent Fasting To Eliminate IBS

Over 2,000 years ago, the Greek physician Hippocrates, now known as the father of medicine, recognized fasting as a healing tool. He believed that disease results from environmental factors, diet, and lifestyle, and he used intermittent fasting as one tool to eliminate disease. 

Intermittent fasting has many beneficial effects on the body, such as increasing autophagy, repairing the immune system, and reducing cancer recurrence. For this article, I will focus on the two key benefits of reducing IBS symptoms: switching from sugar to Ketones for fuel and improving the gut microbiome.  

Sugar For Fuel

Our bodies use two primary fuel sources: Ketones(fat) and sugar. If you are still eating the SAD diet(standard American diet), then sugar is your fuel source. Americans eat sugar from the first bite in the morning until the last bite in the evening: cereals, sweetened yogurt, alternative milk, salad dressings, barbeque sauce, sodas, cookies, candies, juice, and, of course, desserts. I heard a quote that say, “Sugar is the new smoking.” Just as our ancestors were made aware of the health hazards of smoking, we are now becoming aware of the health hazards of too much sugar. It causes inflammation of the intestinal lining, causing a leaky gut and many chronic health conditions, including IBS! Eating excess sugar also increases abdominal fat, causing inflammation and chronic disease in the rest of the body. 

Most of all, sugar as a fuel source is very short-lived. Have you ever experienced being “hangry.” Before I started my health journey, my family used to tease me and say, “Watch out, mom is “hangry” whenever I experienced low blood sugar, which was frequent.  Using sugar as a fuel source is a vicious cycle. When you eat food filled with sugar, the sugar enters the bloodstream, the body releases insulin, which stores the sugar as belly fat. Then your blood sugar drops(hypoglycemia), and you frantically look around for more sugar-filled foods. Then, the cycle starts all over again. 

Ketones for Fuel

When you adopt an intermittent lifestyle, the liver makes ketones when sugar is unavailable(in the fasted state), and stored fat is used to produce ketones. Once you switch to ketones as a fuel source, say goodbye to mood and energy swings! Ketones turn off the hunger hormone in the brain, which is why the more you fast, the less hungry you will become. Ketones can regenerate nervous tissue, so when you switch and your ketone levels rise, you improve memory, increase your ability to retain new information, and increase mental clarity.

My Mistake

I made the mistake of trying to change my endurance training fuel source from sugar to ketones one week before one of the toughest mountain bike races I had ever done, The Grand Traverse. It is a 40-mile cross country race through the Elk Mountains from Aspen to Crested Butte. I knew I could and needed to make this switch, but I did it without doing research, just knowing it needed to be done. Well, I didn’t realize then that it can take over two weeks for your body to switch, and I should have tested my theory on a practice ride before implementing it in a race! As they say, hindsight is 20/20. Well, the start of the Grand Traverse is brutal, 3.6 miles with a 3,000 ft elevation gain straight up Aspen ski resort(climbing isn’t my strong suit!). As you might guess, it didn’t end well for me. I crashed about 15 miles into the race, suffered a mild concussion, and had to drop out of the race. I was lucky enough to catch a ride with a kind volunteer aid station worker, packed in the back of his tiny Subaru, bouncing down the rugged road(if you can call it a road). The boulders on this “road” were so large that sometimes his friend had to get out and move them, or the driver had to stop and analyze the situation to see how he would maneuver around the boulder, like a life-size chess game! 

If you suffer from IBS and need to lose weight, intermittent fasting is for you. Burning ketones for fuel requires fat to build the ketones, and weight loss from fat loss occurs. 

IBS and Intermittant Fasting

If you have IBS and implement intermittent fasting, you will switch from sugar to Ketones as your fuel source. This will decrease inflammation of the gut lining, and you will see that the bloating, gas, constipation, or diarrhea are resolved. This will help balance out the gut microbiome, allowing the good bacteria to flourish and the harmful bacteria to die off, a key to eliminating IBS. 

Balancing The Gut Microbiome

From your mouth to your anus, your intestinal wall is only one cell thick. This means you are one cell away from all the harmful chemicals, viruses, and bacteria you ingest from getting into your bloodstream, making you very ill. There are over 4,000 microbial species, 90% of which are in your gut, working incredibly hard to optimize the function of this one-cell thick lining to keep you healthy. They help pull vitamins and minerals out of your food, help build neurotransmitters to make you happy, and constantly scan your cells for inflammation. 

Fasting improves the health of the gut microbiome by improving microbial diversity, equally distributing the microbes so they perform optimally, and regenerating stem cells that repair the gut lining. 

Summary

In summary, intermittent fasting is just one tool in your toolbox to use if you suffer from IBS. Intermittent fasting alone will not cure your IBS. You must eat the right foods, decrease stress, and eliminate environmental toxins before fasting can work. I would also confess that intermittent fasting can sometimes be challenging, especially the longer fasts like 19-36 hours. But there are so many health benefits that it is worth the effort. So, if you are new on your health journey, I would clean up your diet and lifestyle first and then add intermittent fasting as another tool to uplevel your health.