Fact check: Meat digested like any other protein source

·6 min read

The claim: Because meat has no fiber, body must create mucus to move it through colon

In recent years, Americans have grown more aware of gut health, with gastrointestinal-friendly products such as fermented goods or probiotics increasingly in vogue.

Digestive health was a $40 billion industry in 2019, and Fortune Business Insights predicts it will grow to over $70 billion by 2027.

But the growing discussion around digestive health has spurred an accompanying increase in related misinformation.

One social media claim that misstated the workings of the digestive system was posted June 9 on an Instagram page called @drsebidiet and liked by over 4,500 users. It asserts foods like meat can "get stuck" and "make us sick" while moving through our digestive system because meat is more difficult to digest than fibrous foods.

“Digestive tract is over 6 feet long. No fiber in meat so your body has to create mucus to move it through your colon. What’s making us sick is literally the s--- that gets stuck in the process,” reads the meme, which shows a picture of a digestive tract. “Does this look like it’s designed for meat to travel through?”

Facebook pages that have posted the same meme include Vegan in Oakland.

The @drsebidiet page claims to maintain the legacy of "Dr. Sebi" (real name Alfred Bowman) who became known for his attempts to wean Michael Jackson off of painkillers by "healing people with electric food and herbs." The page links to an online business that sells herbal "healing packages" and "immune booster" supplements. These purportedly reduce acidity in the body, though it has been proven that human blood pH cannot be significantly altered.

Steak is cooked in a saute pan.
Steak is cooked in a saute pan.

Experts say the Instagram post's argument for vegetarianism misrepresents the workings of the digestive system. Meat cannot become "stuck" in the colon as it is digested in the small intestine, and the digestive tract produces mucus to move all foods through the colon, not just meat or foods without fiber in them.

USA TODAY reached out to the Instagram page and to Alkaline Food Solutions, the business to which the page links.

Meat isn’t 'getting stuck' in the colon

The post’s claim evokes the image of a chunk of steak bumping into intestinal walls as the gut frantically ejects slippery mucus to ease its way. But according to multiple experts, the idea that meat “travels through” the colon, and the notion that it could get stuck, doesn't reflect how the digestive system works.

That's because our chunk of steak essentially goes through a biological scrap yard where it's stripped for parts so the system can salvage its nutrients.

The digestive system, or gastrointestinal tract, is a roughly 30-foot long tube running from the mouth down to the anus, where fecal matter exits the body. It's primarily made up of a series of connected organs – esophagus, stomach, small intestine and large intestine – and other nearby organs such as the liver, pancreas and gallbladder that help out with their own digestive juices.

After acid breaks meat down in the stomach, it goes through another round of digestion in the small intestine, Patrice D. Cani, a professor of molecular metabolism and nutrition at the University of Louvain in Brussels, Belgium, said in an email to USA TODAY.

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There, the pancreas releases enzymes that break down the mashed protein into tiny molecules called amino acids. These important molecules are absorbed through the walls of the small intestine and eventually are used by the body for energy, growth and cellular repair, according to the National Institute of Diabetes and Digestive and Kidney Diseases.

What goes on to enter the large intestine, or colon, is the slurried remnants of the food and digestive juices. Unlike the small intestine, no digestion occurs here, only the absorption of water and electrolytes like sodium and potassium. Anything remaining after this exits the body through the feces.

"The question of having meat stuck in the colon is not the case in reality, because the meat will be digested in the upper part of the digestive tract and very few peptides/proteins will reach the colon, not the meat in itself," said Cani.

Gut produces mucus for several different purposes

The post implies that foods without fiber, such as meat, uniquely encourage mucus production in the digestive tract. But mucus plays a role in the digestion of all foods and is present in both carnivores and herbivores, said Geert W. Schmid-Schönbein, a distinguished professor of bioengineering at the University of California San Diego who directs the university’s Microcirculation Laboratory — Center for Autodigestion Research.

According to Schmid-Schönbein, there are two types of mucus in the human digestive tract. One of these is indeed created by the body in order to facilitate the movement of food and waste through the intestines. Made by cells lining the interior of the intestine called goblet cells, this type of mucus detaches as food brushes past the gut's inner walls, making foods slippery and easier to pass through.

Fibrous foods actually stimulate these mucus-producing cells more than meat does, the opposite of what the post claims, said Cani.

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The second type of mucus, which Schmid-Schönbein studies, stays attached to the gut’s interior walls in order to form a “protective barrier.” This barrier prevents digestive enzymes from literally digesting the body's own tissue, while allowing nutrients to pass through the surface of the gut for absorption. Diseases such as Crohn’s disease are characterized by the breakdown of this barrier.

Schmid-Schönbein said digestive enzymes, and therefore the protective mucus layer, need to be present for both fibrous foods and non-fibrous foods, like meat.

Both kinds of mucus are critical for human health, and our diet does have some effect on the mucous lining of the gut – but not in the way the post states. For example, Cani said it has been proven that diets too low in fiber cause the lining to become thinner, but eating some foods without fiber does not mean you are harming the body.

Our rating: False

We rate this claim FALSE, according to our research. Meat cannot become "stuck" in the colon because it is digested in the small intestine and is broken down into nutrients by the time it reaches the colon. It is also misleading to say the digestive tract must produce mucus to move non-fibrous foods through the colon, since the body produces mucus for a host of digestive purposes involving all types of food.

Our fact-check sources:

Contributing: Miriam Fauzia

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This article originally appeared on USA TODAY: Fact check: Body creates mucus to digest all foods, create barrier