Love Your Gut

It’s been hours since you last ate, and your stomach is rumbling. Have you ever wondered what’s making it groan?

I've always found this topic interesting and came across a study this week that helped it make more sense for myself and hopefully now you !

Stomach rumbling is caused by the migrating motor complex, or MMC for short. The MMC is a repeating cycle of powerful contractions that helps push bits of food, bacteria, and other GI junk down toward your colon — sort of like a swallowing reflex that spans your entire gut. The MMC may be one of the most under-appreciated factors when it comes to the health of your digestive system.

“The migrating motor complex refers to recurring contractile waves that swoop down through the intestine,” says Emeran Mayer, MD, a professor of medicine and founding director of the Goodman Luskin Microbiome Center at the University of California, Los Angeles

That’s not all they do. “The initial interpretation of this motor pattern was mainly as housekeeping for the gut,” he says. “But today this has big relevance in terms of the gut microbial habitat.”

Along with pushing any left-over bits of food out of your stomach and upper GI tract, the migrating motor complex also appears to rebalance your gut’s bacteria populations so that more of them are located down in your large intestine, as opposed to higher up in your small intestine. This is a good thing. The normal distribution of your gut microbiome should be heavily weighted toward the lower GI tract, Mayer says. An overgrowth of bacteria in the small intestines is associated with gut dysfunction

To ensure the MMC has enough time to perform its duties, aiming for 14 hours without caloric foods or drinks is a good target, he says. For example, you could avoid all calories between 8 p.m. and 10 a.m. “The 14 hours without food intake would allow the MMC to kick in and not only cleanse your gut of any indigestible, unabsorbable food components, but also to reestablish the normal proximal-to-distal gradient of gut microbial density,” he says.

The weight-loss effects of intermittent fasting plans get most of the attention. But the microbiome benefits of taking breaks from food may ultimately prove to be even more significant.

“People always talk about these cleansing diets or regimens,” Mayer says. “Well, you have the best cleansing regimen built right into your gut if you leave it empty for 12 or 14 hours."

Deloose, E., Janssen, P., Depoortere, I. et al. The migrating motor complex: control mechanisms and its role in health and disease. Nat Rev Gastroenterol Hepatol 9, 271–285 (2012).