Supporting The Vagus Nerve & Migrating Motor Complex

The most successful SIBO doctors recommend retraining the Vagus Nerve and supporting the Migrating Motor Complex as part of SIBO healing and prevention.

The Vagus Nerve

The Vagus Nerve is the main digestive nerve. The Vagus Nerve begins at the base of the brain and travels down through the neck branching off to each digestive organ, and more. This nerve is how the brain speaks to the body to initiate digesting food and releasing biles and acids for digestion as well as to trigger the Migrating Motor Complex. When the brain does not talk to the body, the body may not know when to digest food, or when to move food and bacteria through the intestines. This can create an environment for SIBO to occur.

The Vagus Nerve can be retrained through various means of stimulation. Many doctors recommend gargling water very aggressively, using a tongue depressor to stimulate the gag reflex, and singing really loudly. While SIBO doctors say these methods are the best for stimulating the vagus nerve, there are more options if these don’t jive with your body. Check out this article for more suggestions: 32 Ways To Stimulate Your Vagus Nerve.

Supporting the Migrating Motor Complex

The Migrating Motor Complex or MMC is a cyclical process with four phases in which the body cleans out the digestive system. From the top of the small intestine all of the way to the colon small muscles in and around the intestines contract to push left over food particles, bacteria and other microbiota away from the intestinal wall. The first phase appears to be a rest phase while the second phase includes intermittent irregular contractions. Phase three has short burst of regular high-amplitude contractions and phase four transitions back to the quite state of phase one. The Migrating Motor Complex is triggered by signals from the Vagus Nerve and takes place during “fasting mode” which is 3-4 hours after the consumption of food. Once initiated phase three contractions of the MMC will occur every 90-120 minutes until food is once again consumed. While it is not yet studied if drinking water or tea will prevent the MMC from taking place, doctors recommend waiting to consume food for at least 3 hours (preferably 4 hours) after the last meal in order to give the MMC a chance to initiate. Then, as soon as food is ingested, the stomach will halt the Migrating Motor Complex. This is why snacking is frowned upon by SIBO doctors. Snacking and grazing prevents the MMC from completing its cleaning processes. Without the regular cycles of the MMC bacteria, fungi, and parasites can build up in the small intestine causing overgrowths and unwanted symptoms of gas, bloating, and pain.

As part of cleaning out the small intestines on a daily basis, the Migrating Motor Complex is the body’s natural defense against SIBO. When the MMC is pushing along waste and bacteria away from the intestinal lining and down into the colon, it also pushes SIBO bacteria through the small intestine. So when the Migrating Motor Complex is working properly, the body is naturally keeping the small intestine clean and free of infection. Even if there is no ileocecal valve or the ileocecal valve is not working properly a working MMC will clean the small intestines of unwanted bacteria, waste, and reflux multiple times during a 24 hour period.

In addition to waiting between meals to eat, the MMC can be triggered through various Prokinetics or motility agents such as pharmaceutical drugs like Low-dose Naltrexone or Low-dose Erythromycin , and herbal bitters like ginger and Iburogast. Talk with your doctor about what means of supporting your MMC is best for you.

So how do you know if your vagus nerve and MMC are working properly?

I actually don’t know the answer to this question apart from running some pretty expensive medical tests. One source (I couldn’t find any studies to back this up) suggested up to 70% of SIBO patients have an impaired MMC. You should always talk to your doctor about specifics for you body. As a general rule, the foremost leading SIBO experts (Dr. Siebecker and Dr. Pimentel) recommend supporting the MMC and neurological deficits as part of the prevention of SIBO protocol.

More resources on the Vagus Nerve

• Why Isn’t My Brain Working by Dr. Datis Kharrazian

More resources on the Migrating Motor Complex

• The Migrating Motor Complex
• Migrating Motor Complex in Dogs and Humans
• Mechanism of Interdigestive Migrating Motor Complex
• The Migrating Motor Complex: Control Mechanism and Its Role In Health and Disease
• SIBO Prevention