Could Vagus Nerve Dysfunction Be the Cause of SIBO?

The vagus nerve is the longest of the 12 cranial nerves, running from brainstem to gut and touching multiple organs along the way, including the brain, heart, esophagus, and lungs. It forms part of the parasympathetic nervous system that supports unconscious body processes, such as breathing, heart rate, body temperature and — yes, digestion — by managing communication between organs and the brain via neurotransmitters. While we're accustomed to hearing the media talk about serotonin as a "feel-good chemical in the brain," there are far more serotonin receptors in the gut than anywhere else in the body. That's why so many people with gut issues also deal with symptoms of depression, anxiety and even agoraphobia.

Interacting with the brain, the vagus helps manage anxiety and depression. Interacting with the gut, it controls neurotransmitters and enzymes responsible for the production of stomach acid, digestion, and motility, so having poor vagal tone increases risk of SIBO-C. By releasing intrinsic factor, the vagus nerve also helps with B12 absorption — and that's important because most SIBO-C sufferers are B12 deficient.

People with gut problems are very likely to have vagus nerve dysfunction. The vagus nerve can be damaged by any gut insult, such as food poisoning, antibiotics, chronic infection or illness. Luckily, there are many ways to stimulate the vagus nerve and most are easy and inexpensive. Here are the ones I've worked into my protocol so far:

• Yoga — I'm a beginner and practice a very gentle himalayan yoga with a lot of focus on the breath and relaxation
• 4/8 breathing at random times during the day — a four-counts inhale, eight-count exhale almost immediately calms all systems of the body
• Gargling two days a week — I gargle with warm salt water because it has the added benefit of breaking up biofilms in the mouth and sinuses
• Singing/humming while I drive to work
• Laughter — I've begun actively following comedian podcasts and watching comedy shows and movies

Other things I've learned that may help are coffee enemas and herbal medications that stimulate the postganglionic portion of the vagus nerve, like Parasym Plus.  I haven't been brave enough to try the former,and I'm not ready to add more medicines to my already aggressive daily regimen of supplements right now, but I've made a mental note of these.