Digestive Health, General Health, Probiotic Health

Clarifying SIBO and SIFO – post 1 of 3


This is the first in a series of three posts on the often misunderstood conditions, SIBO and SIFO. My goal in these posts is to clarify these bacterial imbalances.

For the purpose of our talk and also because the symptoms can be similar, from time to time I may simply refer to both conditions as SIBO.

Clarifying SIBO and SIFO – exactly what are they?

SIBO stands for Small Intestinal Bacterial Overgrowth

SIFO stands for Small Intestinal Fungal Overgrowth

In essence, both conditions refer to an increased number and/or an abnormal type of either bacteria or fungus in the small intestinal tract where it doesn’t support healthy GI function.

What happens in the gut for this to occur?

The overwhelming large majority of bacteria and fungus exist in the colon, which is also known as the large intestine. With SIBO or SIFO there can be a backwash of bacteria from the colon, allowing the bacteria to get into the lower part of the small intestine and set up camp, creating imbalances.

Another reason this condition occurs is when there is impaired motility within the digestive tract. That means that the fecal matter isn’t moved through the approximately 22 feet of the small intestine rapidly enough. Stagnant food actually sits and rots. This process is called fermentation and results in the formation of various gases. Initially, constipation and/or diarrhea in addition to gas and bloating can occur.

SIBO can also manifest when undigested food from the stomach, usually at night, travels to the small intestine and stagnates there. Again, the food ferments, often stimulating gas, bloating, and cramping higher up in your digestive system, kind of between your rib bones.

Essentially two main factors are at play with SIBO and SIFO.

  1. An imbalance of the microbes in your gut environment
  2. A disturbance in nervous system function that affects the motility (movement) of your food through the intestine.

Let’s take a closer look at these contributing factors.

Clarifying SIBO & SIFO – Microbes

Let’s look at your microbes.

As mentioned above, an increased number and/or abnormal type of microbes are at the core of both SIBO and SIFO. Your microbiome, the community of microbes in your gut, basically consists of three organisms:

  • Bacteria
  • Archaea
  • Eukarya

Each type is a fascinating study in itself. For our purposes, I want you to grasp that the overgrowth of any group can potentially upset the balance of your health. The different locations you may experience unpleasant symptoms like gas and bloat depend on where the inappropriate microbes are multiplying and fermenting your undigested food. More on that later.

SIBO organisms

Candida is a form of yeast that is normally found in your gut in small amounts. Candida is a unicellular organism. When the gut environment becomes unbalanced and toxic, candida can transform into a multicellular fungus, which may lead to a Leaky Gut.

Clarifying SIBO & SIFO – The Nervous System

Next, how is your nervous system involved?

Muscular contractions of multiple types transport your food through the digestive process. These contractions are controlled by different aspects of your nervous system.  Most commonly, we think of the word “peristalsis” when referring to digestive motility. However, there is another very important process that affects motility and is often at the core of SIBO issues. Hang in there with me.

I’m sure you’re familiar with the central nervous system that travels down your spine. Within that is found the autonomic nervous system that is in charge of how organs like your heart and lungs operate. The autonomic nervous system is divided into parasympathetic and sympathetic brances that coordinate resting and stimulating responses.

Did you know that there is actually another entire nervous system called the Enteric nervous system that resides entirely within your gut? It’s embedded in your small intestine and can operate independently of your other nerves although it most often relies on the input of the Vagus nerve.

The Vagus nerve is Cranial Nerve 10. Also known as the wandering nerve, it travels throughout your body. It also interacts with the heart and lungs. Additionally, it assists with the mind-body connection. Through its actions with the enteric nervous system, the vagus nerve assists with digestion. It interacts with the migrating motor complex, another critical way that food is moved through your system.

What is the Migrating Motor Complex (MMC)?

SIBO - migrating motor complex

The migrating motor complex also called the MMC for short, stimulates gastric motility. As you now know, motility means movement. This is literally how your digestive system moves food, toxins, and bacteria through your gut and then out of your body. The MMC is very different from peristalsis.

The MMC is known as the housekeeping motor of the gut. It is neurologically stimulated by the hormone motilin, which is produced when your stomach is empty. It also responds to input from the Vagus nerve. Keep this in mind. This becomes very important later.

By the way, good bacteria also stimulate the movements of the MMC.

An impaired MMC is the number one cause of SIBO and SIFO!

Clarifying SIBO and SIFO – Over time, what are the identifying symptoms?

SIBO - burning gut
  • Gas & Bloating
  • Abdominal Pain
  • Fatigue
  • Nutritional Deficiencies
  • Malabsorption/Leaky Gut
  • Nonalcoholic Fatty Liver Disease (NAFLD)

SIBO and SIFO were formally known as IBS and Candida Overgrowth! Have you heard those terms before?

Our next post will take a closer look at the causes of these conditions. Check out my video on Facebook for even more information.

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