Defence mechanisms
against SIBO

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Defence mechanisms against SIBO

Medically reviewed by:
Dr James Freeman

Main defence mechanisms against SIBO:

An overpopulation of bacteria in your small intestine is a grade one potential health threat hence the body will have to initiate defence mechanisms to keep things under control.

Sometimes these don’t work correctly, and that’s when SIBO can occur.

The bodies fundamental defense mechanisms against SIBO are:

• acidic from the stomach
• downward propulsive impulses (wave-like movements) such as peristalsis and the migrating motor complex (MMC)
• secretion of Bile from the gallbladder
• immunoglobulins in the small intestine (that fight bacteria and other pathogens)
• ileocecal valve, a one-way valve connection between the small intestine and large intestine

The science behind your body’s defense mechanisms against SIBO:

1. The structural defense – The Pyloric valve and
the ileocecal valve

The small intestine has an entry (Pyloric valve), and an existing (ileocecal valve). The entry is controlled by the pyloric sphincter/valve, which separates the stomach from the duodenum. This is where the small intestines begin. The exist is the ileocecal valve. That is the end of the small intestine before the beginning of the secum (which is part of the large intestine). The secum is incredibly important as it stops bacteria present in the large intestine from entering the small intestines. Sometimes, these don’t work correctly or become impaired.

2. The chemical defense – Digestive enzymes, Hydrochloric acid, Bile

Digestive enzymes – The enzymes are present in our saliva. The pancreas is responsible for most of the digestive processes that help us break down our food properly.

Hydrochloric acid – The acid is made by our stomach and helps us break down protein. It also helps break down any bacteria in the food we eat before it travels further.

Bile – The gallbladder stores bile, which helps us digest fats in our diet.

3. The motility defences

We have something called a migrating motor complex. It is a wave of movement that goes through our small intestine. It propels undigested food residue and sloughed enterocytes out of the small intestine. It’s essentially the housekeeper in the small intestines.

Although the small intestine is narrower than the large intestine, it’s the most extended section measuring 20 feet or 1.5 meters. So, it’s not that small. So roughly every 90 minutes, peristalsis (the involuntary contraction and relaxation of the intestine muscles) occurs to make sure bacteria and food don’t sit there too long.