If you have found yourself snacking more these past few months you are definitely not alone.
And I am not here to tell you to stop, or that it's a bad thing to do. My approach to nutrition is not about restriction, deprivation, or stressing about how much you are eating.
However, I do want to talk about the migrating motor complex (MMC) and its role in maintaining healthy gut function.
What is MMC? Migrating Motor Complex is a sequence of muscle contractions throughout the digestive system that acts as a 'cleaning wave' to help keep contents moving along. (1,3)
These cleaning waves occur after ~ 90 mins of fasting. The majority of the cleaning waves happen at night while we are asleep, and for many people this will be sufficient enough to help maintain a healthy, balanced environment in the digestive tract. For others, it may be beneficial to space out food intake to allow for a couple cleaning waves to occur between meals throughout the day as well.
If you are someone that experiences bloating or other digestive issues, it may be worth trying out a few different options when it comes to supporting the MMC.
Whether or not snacking in between meals is a new habit or something you have always done, try spacing out your snacks/meals by about 4 hours, and only having water in between.
To help maintain this eating schedule, it is important to eat enough at each meal, and for the meals to include plant based proteins, healthy fats, and complex carbohydrates.
This type of eating schedule won't be suitable for everyone, and it may be difficult for athletes to get the calories they need by just eating 3 meals a day.
If you try it and feel it doesn't work for you, you could try instead to increase the length of time you are not eating between dinner and breakfast the next day in order to help increase the number of cleaning waves that happen at night (aim for a 12-13 hour window). Then, throughout the day, you may be able to have more frequent meals (i.e. every 2.5-3.5 hours) since you'll likely be increasing the cleaning waves that happen between dinner and breakfast the next day.
Again, everyone is different so it will be important to figure out what works for you.
Obviously, this alone may not solve all of your digestive issues, but it is a piece of the puzzle that's worth considering when dealing with bloating, indigestion, heartburn, and other symptoms associated with SIBO or IBS.
There are multiple underlying factors that can contribute to decreased activity of the MMC:
MMC & the Vagus Nerve:
The health of your vagus nerve can sometimes be the missing piece of the puzzle when it comes to examining the root cause of gut imbalances. Work with your doctor to determine whether or not your vagus nerve or MMC may be involved with your digestive symptoms.
The vagus nerve is a 2-way highway of communication between the gut and the brain. (7) And they influence each other in both directions. Low vagal tone can lead to gut disfunction and dysbiosis, and dysbiosis can lead to low vagal tone. (10)
There are many factors when it comes to the involvement of the vagus nerve with digestive health. Low vagal tone may be involved with:
There are a number of simple ways to support the health of the vagus nerve (12):
MMC & IBS/SIBO:
There are often gut motility issues and MMC irregularities involved with Irritable Bowel Syndrome (IBS) and Small Intestinal Bacterial Overgrowth (SIBO). (9)
"The MMC has been considered an “intestinal housekeeper” that prevents SIBO" (9)
Your doctor may include short-term use of prokinetics after SIBO treatment to help prevent relapse (prokinetics stimulate gut motility and MMC - however it is still important to try to figure out the underlying reason(s) for the gut motility/MMC issues as prokinetics are not always a suitable long-term solution)
It is important to treat SIBO and determine the underlying causes of SIBO (2,9), IBS and other digestive issues since SIBO and other gut imbalances eventually lead to nutrient deficiencies and other chronic health issues.
There are many possible underlying causes when it comes to digestive issues, and the MMC and health of the vagus nerve is only one area of possibility. However, it is one that is important to talk to your doctor about, especially when many other factors have already been ruled out as a cause, or have been addressed in your treatment protocol.
Shawna Barker BSc., R.H.N. is a nutritionist, vegan chef, college instructor, and an expert in plant based nutrition. She graduated with honours from the University of British Columbia with a Bachelors of Science degree in Food, Nutrition and Health, as well as the Canadian School of Natural Nutrition with a Diploma in Holistic Nutrition.