Study Links Depression With Gut Bacteria Imbalance

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iStock

The future of depression treatment might be chilling in the dairy case. A study published earlier this year in Nature Scientific Reports said that beneficial bacteria commonly found in yogurt can help relieve depression-like symptoms in mice.

Over the last few decades, scientists have begun exploring the connections between our brains and all the microbes that live on and inside our bodies, and they've learned that those little microbes have an awful lot of power. Some studies have shown that bacterial imbalances can affect nervous system function, while others have suggested that people with bacterial imbalances may be more prone to anxiety and depression.

To test these hypotheses, researchers at the University of Virginia decided to begin at the overlap between the nervous system and mood: stress. Stress increases depression risk; it also affects, and is affected by, the function of the nervous system.

The scientists began by collecting a group of unlucky mice and subjecting them to a variety of intense stressors. Some were kept in crowded cages; others had to sit under strobe lights or listen to loud noises. Predictably, the stressful situations took a toll, and the mice began exhibiting what the researchers called “despair behavior.”

The researchers collected poop samples from the mice before and after the stress sessions, then ran genetic analyses to determine the species and quantities of bacteria living in each mouse’s gut. The results showed that the stress resulted in a pretty significant drop in a microbe called Lactobacillus—the same type of so-called "good" bacteria found in yogurt.

But the rodents’ despair would not prove permanent. The researchers began giving the mice small doses of Lactobacillus with their meals, and, over time, their symptoms resolved.

Lead author Alban Gaultier. Image Credit: Josh Barney | University of Virginia Health System

 
"This is the most consistent change we've seen across different experiments and different settings we call microbiome profiles," co-author Ioana Marin said in a statement. "This is a consistent change. We see Lactobacillus levels correlate directly with the behavior of these mice."

The team hopes to take their experiments into the human body next. Lead author Alban Gaultier said he has “big hope” that probiotics could someday augment or even replace side-effect–heavy antidepressant drugs. “It would be magical just to change your diet,” he said, “to change the bacteria you take, and fix your health—and your mood.”

Why Is Pee Yellow?

Chloe Effron
Chloe Effron

WHY? is our attempt to answer all the questions every little kid asks. Do you have a question? Send it to why@mentalfloss.com.

Your body is kind of like a house. You bring things into your body by eating, drinking, and breathing. But just like the things we bring home to real houses, we don’t need every part of what we take in. So there are leftovers, or garbage. And if you let garbage sit around in your house or your body for too long, it gets gross and can make you sick. Your body takes out the garbage by peeing and pooping. These two things are part of your body’s excretory system (ECKS-krih-tore-eee SISS-tem), which is just a fancy way of saying “trash removal.” If your body is healthy, when you look in the toilet you should see brown poop and yellow pee.

Clear, light yellow pee is a sign that your excretory system and the rest of your body are working right. If your pee, or urine (YER-inn), is not see-through, that might mean you are sick. Dark yellow urine usually means that you aren’t drinking enough water. On the other hand, really pale or colorless pee can mean you might be drinking too much water! 

Your blood is filtered through two small organs called kidneys (KID-knees). Remember the garbage we talked about earlier? The chemicals called toxins (TOCK-sins) are like garbage in your blood. Your kidneys act like a net, catching the toxins and other leftovers and turning them into pee.

One part of your blood is called hemoglobin (HEE-moh-gloh-bin). This is what makes your blood red. Hemoglobin goes through a lot of changes as it passes through your body. When it reaches your kidneys, it turns yellow thanks to a chemical called urobilin (yer-ah-BY-lin). Urobilin is kind of like food coloring. The more water you add, the lighter it will be. That's why, if you see dark yellow pee in the toilet, it's time to ask your mom or dad for a cup of water. 

To learn more about pee, check out this article from Kids Health. 

Scientists Discover How to Snap Spaghetti Into Two Perfect Pieces

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iStock

Important news for pasta lovers: Researchers at MIT just figured out how to snap a strand of spaghetti into two perfect pieces, according to New Scientist. The days of having to sweep up the tiny fragments that fly in all directions when you break spaghetti into two pot-ready portions are over.

In 2005, researchers in France figured out why spaghetti cracks into bits: The strand flexes in the opposite direction after the initial snap, creating a “snap-back effect” that causes it to break a second time.

Now, after snapping hundreds of spaghetti sticks, MIT mathematicians have the solution. The researchers used a pair of clamps to twist individual strands of spaghetti almost 360 degrees. Next, the two clamps were slowly brought together to bend the stick, resulting in a perfect fracture. This worked for two kinds of spaghetti with different thicknesses—Barilla No. 5 and Barilla No. 7, to be precise.

The process was recorded using a high-speed camera (which can be viewed on MIT's website). While reviewing the footage, researchers realized that adding a twist is key because it prevents the spaghetti stick from forcefully flexing backwards. Their findings were published in the Proceedings of the National Academy of Sciences.

Even without equipment, you can can try this at home. It might take a bit of practice, though, so have a couple of boxes handy. Ronald Heisser, a former MIT student who is now a graduate student at Cornell University, came up with the technique for how to manually snap spaghetti in two.

“I would start with my hands opposite each other—one hand upside down and the other right side up—and then make both of them right side up while twisting the spaghetti so you can work your arm strength into it,” Heisser tells Mental Floss.

“You know you're twisting it right when you feel it really trying to untwist itself. Then, you can carefully bring the ends together, trying not to change the twist at all.”

He noted that your hands should also be dry, because oiliness can make the strand slip in your fingers.

However, it's unlikely that anyone has the patience to sit there and snap one strand of spaghetti at a time. So does this trick work for a whole handful of pasta? Dr. Jörn Dunkel, who led the study, says it’s difficult to predict how a handful of spaghetti would fracture, but he believes this technique would reduce the number of pieces you end up with.

“When many spaghetti [strands] become bunched together, they can transfer energy between them, which can change their bending and fracture behavior significantly,” Dr. Dunkel tells Mental Floss. “Very roughly, as a rule of thumb, one would expect that splitting the energy between bending and twisting should always help to reduce the fragment number compared to pure bending.”

Of course, if you want to cook the true Italian way, you’ll leave your spaghetti unsnapped and intact. (Longer pasta is said to wrap around your fork better, making it easier to eat.)

But if you want to try this bend-and-snap technique for yourself, the purists would probably give you a pass.

[h/t New Scientist]

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