Pathogenic and dysbiotic bacteria don’t sound great, and inside your gut, they’re not. Imagine these types of bacteria as unwelcome visitors who have overstayed their invite. Rather than leaving when requested, they make themselves very comfortable in our gut. Because we are such amazing hosts, we, much to our disgust, sometimes can’t say “no” to their demands for junk, processed, and sugary foods. We might even secretly enjoy it until these hyperactive, undesirable visitors decide to go around wreaking havoc inside our intestinal walls! It’s time we take a firm stand and no longer feed these unwelcome visitors. No means no. Because these pathogenic bacteria are constantly hungry and needing food, food deprivation is their worst nightmare! That is why purification is the first step to a resilient gut.
The, "Bacteria are Hungry," Problem
Once our gut microbiome (the majority of our gut microbiome is made up of bacteria) is out of balance, it can be quite tricky to bring it back to harmony. Part of the difficulty is that the bacteria in our gut play a big part in determining what we want to eat and how much. The more we eat of one food, the more desirable that type of food is to our microbiome. Sweet, processed and high carb food contains readily available bacteria-food, allowing sugar-loving bacteria to populate and reproduce at a very fast rate. Sugar-loving bacteria have a much shorter life cycle than other types of bacteria such as: fibre-loving, fat-loving or protein loving bacteria. This means that if we give in and start eating sweet, processed junk our gut bacteria want more, fast!
Here’s how it works. We eat junk, our microbiome wants more junk. We eat more junk which usually means that we have a lower diversity of prebiotic foods and the diversity of our gut microbiome decreases, now dominated by a few hungry strains of junk-loving pathogenic or dysbiotic bacteria.
Currently, antibiotics and other medication are commonly used to treat imbalance or dysbiosis in a problematic microbiome, but this is like fighting fire with fire. Antibiotics are fairly indiscriminate killers, and wipe out huge chunks of the beneficial bacteria along with the harmful bacteria. This has longer term consequences.
With a strong will and enough time, it is possible to change the makeup and diversity of our gut bacteria through diet and lifestyle alone. But there is a shortcut that we can use to turbocharge the process of clearing out the problematic bacteria in our gut. Clearing out our gut is a very important step before rebuilding a flourishing ecosystem of beneficial microbiome.
The “Autophagy” problem
Autophagy (self-eating), is the process in which our body breaks down (eats) old, damaged, mis-formed and misplaced cells, proteins, bacteria and viruses. As our body breaks down the unwanted bits, it recycles the building blocks and uses them to build new, components for our body. If autophagy doesn't occur as regularly or as efficiently as needed we start to run in to trouble. Importantly, autophagy has been linked to the makeup of our microbiome and the health of our gut lining.
The lining of our gut is important as it has to let beneficial nutrients through, while keeping pathogenic, and damaging things in the gut, later to be expelled. We'll look more at the gut lining the next blog post. If the gut lining lets things through that it shouldn't like: chunks of food, viruses, bacteria etc, inflammation occurs and the whole microbiome is thrown out of balance. Autophagy has been shown to tighten up the gut lining so that it can keep doing its job.
Autophagy has also been shown to cleanse the gut lining of pathogenic bacteria and bacteria that are living where they shouldn't be (sometimes bacteria make their home between the cells of our gut lining). Although it's constantly occurring at slow rates, there are some ways we can drastically increase the rate of autophagy in our body.
Fasting: The Easy Answer
The rough estimate of 100 trillion bacteria found in our microbiome is thought to weigh 1-3kg (the exact number is hard to measure and varies from person to person). When fasting, there is a significant decrease in the number and weight of bacteria. It’s thought that the number of bacteria in the gut can decrease by 60% over 3 days of fasting, but it’s hard to measure exactly. Animal research shows that after fasting for 4 days the mass of gut bacteria was reduced by approximately 93%.
The bacteria that are first to die off during a fast are the bacteria feeding on sugar and carbohydrates. The bacteria needing the quick carb hit die fast. Fasting for 2-3 days is a surprisingly effective way of killing off many pathogenic and dysbiotic bacteria from our microbiome.
Because fasting disrupts our gut microbiome by starving our pathogenic bacteria and reducing our microbiome down to the essentials, research has shown that a new diet started after a fast is significantly more beneficial when compared to starting a new diet without first fasting.
More than this, fasting has been shown to supercharge the process of autophagy. While autophagy occurs at low levels all the time, if our body has constant access to new food, autophagy is sidelined in favour of processing the easy new building blocks that are entering our body through our mouth. When we fast, there's no longer any food entering our stomach, so our GI tract has no new food to use, instead it starts to break down all the inefficient and problematic cells in our GI tract. Depending on lots of factors like: how much we last ate, what we last ate, how physically active we've been and how fast our metabolism is, autophagy can start to ramp up after 14 hours of fasting. Autophagy really kicks into gear after about 48 hours, when our whole GI tract is empty, from our stomach to our colon.
How Do I Fast?
When fasting to purify, it’s important to fast from all forms of energy, especially carbohydrates and proteins. Anything we ingest that provides energy for our body will also feed our bacteria to some degree. Even juice fasts have a limited effect on changing gut bacteria when compared to water-only fasting. That is because fruit and vegetable juices contain plenty of carbohydrates and even bits of insoluble fibre that are sufficient to maintain the relative stability of our microbiome.
Water-only fasting is the best way to purify our gut. Drinking non-caloric beverages with a bitter taste during a fast also seems to also do the same job. Beverages such as green tea, black tea, black coffee, dandelion tea, etc. provide no energy so long as the tea leaves are removed after steeping. Teas such as matcha or hoji-cha that are normally prepared by mixing the tea powder into hot water are not ideal while fasting since the tea powder often contains enough fibre to give our gut bacteria a food hit.
It’s important not to have teas that taste sweet, even if they have no sugar in them. Teas such as licorice tea, honeybush tea, teas with added stevia, or added essential oils can sometimes taste sweet, even if there’s no sugar calories of any sort. If our body recognises the sweet taste it can sometimes release insulin, even if there’s no sugar to deal with. This insulin release can knock us out of a fasting state, making it more difficult to continue the fast.
Is Fasting Safe?
Fasting has been proven to be safe, especially if we keep our hydration up and add a little salt to our water. Researchers studied 768 people who had done a water-only fast for more than 2 consecutive days. While there were some expected adverse events such as headaches, fatigue, insomnia, back pain etc., there were only 2 hospitalizations. One hospital visit was for a 73-year-old man who had fasted for 3 days without drinking anything. He was dehydrated and recovered after being rehydrated. The other hospital visit was for a 70-year-old man who was found to have hyponatremia (low in salt) on day 9 of his water-only fast! This man recovered after being administered electrolytes.
When fasting, we should drink lots of water (or tea). Make sure to add a little salt to the water, especially if we’re fasting for longer than 2 days. Low salt can cause heart palpitations, fatigue, insomnia, and many other problems. It’s amazing how much vital salt we get from food. Without food, we flush our system of salt pretty quickly.
Both religious fasting and limited food supply in rural life have been a part of life for thousands of years. The western diet and an overabundance of food have become problematic for many people. In 2010, for the first time, across the globe, more disease was associated with people having too much to eat rather than having too little. We need to learn to change our relationship with food, both for us and our microbiome.
Other Benefits of Fasting
Fasting is a great way to starve problematic bacteria so that we can start fresh, but fasting also has many other benefits. Fasting has been found to:
Increase autophagy (clean out the bad and damaged parts of the body)
Reduce oxidative stress (which contributes to ageing)
And guess what? Fasting is free!