8 Surprising Facts About the Stomach

The human body is an amazing thing. For each one of us, it's the most intimate object we know. And yet most of us don't know enough about it: its features, functions, quirks, and mysteries. Our series The Body explores human anatomy, part by part. Think of it as a mini digital encyclopedia with a dose of wow.

While you may only think of your stomach when you're eating or it catches your attention with a gurgle or burble, it's much more than a repository for the food you eat. Your stomach kills microbes, secretes hormones and mucus, and absorbs nutrients. Here are eight gut-clenching facts you might not have known:

1. IT HAS SOME SERIOUS STORAGE CAPACITY.

Your stomach at rest holds about 7 ounces of stomach acid and bile. However, it has the capacity to hold nearly a half-pound of food at a time if necessary. (The average capacity is about 32 ounces, or a quarter-gallon.) It normally takes from four to six hours to digest one meal, so this capacity can be important.

2. PH BALANCE AND MUCUS PREVENT ACID FROM CORRODING YOUR STOMACH.

"Thanks to the high production of hydrochloric acid, which is highly potent, the stomach regenerates its lining frequently," says Sydney Ziverts, a health and nutrition investigator for ConsumerSafety.org. The stomach cavity has a powerful protective process in place that normally keeps the pH of the stomach balanced. Potassium ions help to modulate the hydrochloric acid, and the stomach lining itself produces high numbers of goblet mucus cells to protect the lining.

3. IT ALLOWS YOU TO ABSORB THE CRUCIAL VITAMIN B12 OUT OF YOUR FOOD.

Your stomach is responsible for helping to release the crucial vitamin B12 [PDF] from the proteins you eat. Hydrochloric acid and an enzyme called pepsin break the locked B12 out of its protein so it can be absorbed into your blood stream. "The metabolism of vitamin B starts in the stomach in the parietal cells," Lisa Ganjhu, associate professor of gastroenterology and hepatology at NYU Langone Medical Center, tells Mental Floss. Vitamin B "is one of the main vitamins in our body to help with metabolism and energy production," she says.

4. IT'S A HORMONE-GENERATING MACHINE.

Eating and digesting your food is most likely something you never have to think about. Yet your GI tract is home to a veritable orchestra of hormones stimulated by epithelial cells that line the stomach and small intestine. These hormones engage in a wide range of functions, including stimulating appetite, encouraging the secretion of enzymes and gastric acid, and reminding the gall bladder to contract and empty. These hormones directly enter the blood, and eventually affect the function of other parts of the digestive system, including the liver and pancreas, and even your brain.

5. YOUR STOMACH IS ONE OF YOUR IMMUNE SYSTEM'S FIRST LINES OF DEFENSE.

Besides just digesting your food, the stomach helps protect your entire body. "The acidity in our stomach helps to sterilize whatever you're eating. It kills off bacteria and potential food toxins," says Ganjhu. Your gastrointestinal tract also has patches of lymphoid defense cells it sends out when something makes it through the stomach, such as a virus or bacterial infection.  

6. AND IT MAY PLAY A PART IN YOUR MOOD, TOO.

Your stomach may very well be a key player in keeping your mood balanced. New research suggests links between the gut microbiome—the microorganisms that live in any environment—and your mental health. A recent study in the Journal of Psychiatric Research found that transferring the gut microbiota of depressed human patients into rats induced depressive symptoms in the rodents, opening up a whole new realm of possible bacteria-based treatments.

7. STOMACH FLU ISN'T ACTUALLY A FLU.

If you've ever had the misfortune to find yourself stranded by the toilet for 24 to 48 hours purging the contents of your stomach, you may have described the cause as a stomach flu. However, actual influenza is primarily a respiratory infection. What keeps you in the bathroom is likely some form of norovirus or rotavirus, which causes gastroenteritis of the stomach and intestines, and usually resolves in one to two days.

8. THE MOST COMMON CAUSE OF STOMACH ULCERS IS LIKELY BACTERIAL.

The causes of ulcers have perplexed medical researchers for years. However, recent studies have found a link between the bacteria H. pylori and inflammation of the stomach lining, gastritis, and ulcers. In fact, new research suggests that the bacteria may also be linked to stomach cancer.

10 Products for a Better Night's Sleep

Amazon/Comfort Spaces
Amazon/Comfort Spaces

Getting a full eight hours of sleep can be tough these days. If you’re having trouble catching enough Zzzs, consider giving these highly rated and recommended products a try.

1. Everlasting Comfort Pure Memory Foam Knee Pillow; $25

Everlasting Comfort Knee Pillow
Everlasting Comfort/Amazon

For side sleepers, keeping the spine, hips, and legs aligned is key to a good night’s rest—and a pain-free morning after. Everlasting Comfort’s memory foam knee pillow is ergonomically designed to fit between the knees or thighs to ensure proper alignment. One simple but game-changing feature is the removable strap, which you can fasten around one leg; this keeps the pillow in place even as you roll at night, meaning you don’t have to wake up to adjust it (or pick it up from your floor). Reviewers call the pillow “life-changing” and “the best knee pillow I’ve found.” Plus, it comes with two pairs of ear plugs.

Buy it: Amazon

2. Letsfit White Noise Machine; $21

Letsfit White Noise Machine
Letsfit/Amazon

White noise machines: They’re not just for babies! This Letsfit model—which is rated 4.7 out of five with nearly 3500 reviews—has 14 potential sleep soundtracks, including three white noise tracks, to better block out everything from sirens to birds that chirp enthusiastically at dawn (although there’s also a birds track, if that’s your thing). It also has a timer function and a night light.

Buy it: Amazon

3. ECLIPSE Blackout Curtains; $16

Eclipse Black Out Curtains
Eclipse/Amazon

According to the National Sleep Foundation, too much light in a room when you’re trying to snooze is a recipe for sleep disaster. These understated polyester curtains from ECLIPSE block 99 percent of light and reduce noise—plus, they’ll help you save on energy costs. "Our neighbor leaves their backyard light on all night with what I can only guess is the same kind of bulb they use on a train headlight. It shines across their yard, through ours, straight at our bedroom window," one Amazon reviewer who purchased the curtains in black wrote. "These drapes block the light completely."

Buy it: Amazon

4. JALL Wake Up Light Sunrise Alarm Clock; $38

JALL Wake Up Light Sunrise Alarm Clock
JALL/Amazon

Being jarred awake by a blaring alarm clock can set the wrong mood for the rest of your day. Wake up in a more pleasant way with this clock, which gradually lights up between 10 percent and 100 percent in the 30 minutes before your alarm. You can choose between seven different colors and several natural sounds as well as a regular alarm beep, but why would you ever use that? “Since getting this clock my sleep has been much better,” one reviewer reported. “I wake up not feeling tired but refreshed.”

Buy it: Amazon

5. Philips SmartSleep Wake-Up Light; $200

Philips SmartSleep Wake-Up Light
Philips/Amazon

If you’re looking for an alarm clock with even more features, Philips’s SmartSleep Wake-Up Light is smartphone-enabled and equipped with an AmbiTrack sensor, which tracks things like bedroom temperature, humidity, and light levels, then gives recommendations for how you can get a better night’s rest.

Buy it: Amazon

6. Slumber Cloud Stratus Sheet Set; $159

Stratus sheets from Slumber Cloud.
Slumber Cloud

Being too hot or too cold can kill a good night’s sleep. The Good Housekeeping Institute rated these sheets—which are made with Outlast fibers engineered by NASA—as 2020’s best temperature-regulating sheets.

Buy it: SlumberCloud

7. Comfort Space Coolmax Sheet Set; $29-$40

Comfort Spaces Coolmax Sheets
Comfort Spaces/Amazon

If $159 sheets are out of your price range, the GHI recommends these sheets from Comfort Spaces, which are made with moisture-wicking Coolmax microfiber. Depending on the size you need, they range in price from $29 to $40.

Buy it: Amazon

8. Coop Home Goods Eden Memory Foam Pillow; $80

Coop Eden Pillow
Coop Home Goods/Amazon

This pillow—which has a 4.5-star rating on Amazon—is filled with memory foam scraps and microfiber, and comes with an extra half-pound of fill so you can add, or subtract, the amount in the pillow for ultimate comfort. As a bonus, the pillows are hypoallergenic, mite-resistant, and washable.

Buy it: Amazon

9. Baloo Weighted Blanket; $149-$169

Baloo Weighted Blanket
Baloo/Amazon

Though the science is still out on weighted blankets, some people swear by them. Wirecutter named this Baloo blanket the best, not in small part because, unlike many weighted blankets, it’s machine-washable and -dryable. It’s currently available in 12-pound ($149) twin size and 20-pound ($169) queen size. It’s rated 4.7 out of five stars on Amazon, with one reviewer reporting that “when it's spread out over you it just feels like a comfy, snuggly hug for your whole body … I've found it super relaxing for falling asleep the last few nights, and it looks nice on the end of the bed, too.” 

Buy it: Amazon 

10. Philips Smartsleep Snoring Relief Band; $200

Philips SmartSleep Snoring Relief Band
Philips/Amazon

Few things can disturb your slumber—and that of the ones you love—like loudly sawing logs. Philips’s Smartsleep Snoring Relief Band is designed for people who snore when they’re sleeping on their backs, and according to the company, 86 percent of people who used the band reported reduced snoring after a month. The device wraps around the torso and is equipped with a sensor that delivers vibrations if it detects you moving to sleep on your back; those vibrations stop when you roll onto your side. The next day, you can see how many hours you spent in bed, how many of those hours you spent on your back, and your response rate to the vibrations. The sensor has an algorithm that notes your response rate and tweaks the intensity of vibrations based on that. “This device works exactly as advertised,” one Amazon reviewer wrote. “I’d say it’s perfect.”

Buy it: Amazon

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.

30 Pungent Facts About Farts

This man is clearly not trying to hide the fact he just passed gas.
This man is clearly not trying to hide the fact he just passed gas.
BrilliantEye/iStock via Getty Images

Whether you openly admit it or desperately try to hide it, it’s an undeniable fact that every living and breathing human being farts. And while passing what you thought was going to be silent gas only to be wrong in certain situations can definitely be embarrassing, there’s something undeniably humorous about flatulence—no matter your age.

If you do love a good fart joke, you’re in good company. The very first recorded joke, which was written by the Sumerians and dates all the way back to 1900 BCE, was about—you guessed it—breaking wind. And some of the world's great thinkers, from William Shakespeare to J.D. Salinger, have slipped a fart joke (or 10) into their work.

In this episode of The List Show, we're sniffing out 30 fascinating facts about farts—from why humans expel gas to how often the average adult squeezes the cheese. You can watch the full episode below.

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