What is SIBO? What causes SIBO?

(If you only skim this article, the last paragraph is the most important.)

SIBO (Small Intestinal Bacterial Overgrowth) is an overgrowth of bacteria in the small intestines, but it is complex. To understand SIBO, we need to define a few important keywords and understand some gut basics.

We all have a microbiome (microbiota), the trillions of microbial species that live within us. These bacteria, fungi, and yeast play an important role in how we function.  We have learned how to co-evolve with the microbial universe in an unprecedented way. We are a host to an incredibly complex ecosystem and live symbiotically with our microorganisms.

Think of an ecosystem; rain forest, desert, or ocean. Like an ecosystem, our microbiota needs balance or symbiosis to function optimally. The microbes need to have a functionally beneficial relationship with each other.

Each bacteria, yeast, and fungi belong to a certain species, like how an ecosystem has many different animal species. There are about 1200 identified species in the human body and trillions of strains within those species (there are most likely many more species, but we have yet to identify them).

Just like an ecosystem needs biodiversity, we need biodiversity in our gut. Biodiversity is the variety of life in the world or a particular habitat or ecosystem!

How does the Microbiome become unbalanced?

More on this topic below, but stress, poor diet, toxins, or physical obstructions can change our microbiota’s environment and cause overgrowth or undergrowth of certain bacterial or fungal species. 

The species in our gut need to maintain a symbiotic relationship. Certain species perform essential functions like producing Short Chain Fatty Acids, T and B cells (essential for our immune system), and hormones. 

They do all of these things by assisting with digestion! They feed on fiber and starch, and other foods we eat. I’m not going to get too sciency, but it is important to know that the food we eat is food for our gut microbiota.

If these functions do not happen because there is a lack of certain species, we may face many health issues. A situation where the species within our gut is out of balance is called dysbiosis. Meaning, our bacterial species now have a dysbiotic or unbalanced relationship.

So, SIBO is a form of dysbiosis. It does not define dysbiosis. When SIBO is present, there are most likely many other contributing factors causing dysbiosis.

Certain microbes are overgrown and in the wrong place (the small intestines). All bacterial species should mostly live in the large intestine, NOT the small intestine. When we have an overgrowth of bacteria invading the small intestines, we experience symptoms related to SIBO.

What are some symptoms of SIBO?

  • bloating (often wake up bloated)
  • gas (foul/smells of methane)
  • diarrhea
  • constipation
  • both diarrhea and constipation
  • abdominal pain/cramping after eating
  • brain fog
  • fatigue
  • symptoms worse in the evening or nighttime
  • excessive burping

What causes an imbalance of bacteria, yeast or fungi in the gut?

Well, that’s the million-dollar question. It is different for all of us because no two microbiomes are the same, just like everybody has their own genetic code. This means that everyone is affected by their environment and diet differently, and some may be genetically predisposed to dysbiosis or SIBO.

Here are some possible causes:

  • A bad bout of food poisoning or stomach flu, which negatively affects motility. (Motility– a natural wave triggered by the nervous system (Migrating Motor Complex, MMC) to help move food out between meals.)
  • Nervous System malfunction (MCAS, POTS, Dysautonomia)
  • Antibiotics
  • Intestinal Permeability
  • Poor Diet (processed foods, high sugar, high simple carbs, non-organic foods)
  • Inflammation
  • Chronic Stress

SIBO is complex because it is a secondary infection. This means that something else is malfunctioning in the body, causing an overgrowth to happen. While it is important to understand the basic concepts about SIBO, we should know the best way to address SIBO is from a “root cause” or “whole body” approach. If we do not consider underlying contributors, we may perpetuate relapse.

Written by @monicaboyle @betterhealthbymonica

Published by monicaboyle

I am a Health Coach and Pilates instructor. I strive to help people find their food freedom and digestive relief so they can become limitless!

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