Study Links Depression With Gut Bacteria Imbalance

iStock
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.”

No Venom, No Problem: This Spider Uses a Slingshot to Catch Prey

Courtesy of Sarah Han
Courtesy of Sarah Han

There are thousands of ways nature can kill, and spider species often come up with the most creative methods of execution. Hyptiotes cavatus, otherwise known as the triangle weaver spider, is one such example. Lacking venom, the spider manages to weaponize its silk, using it to hurl itself forward like a terrifying slingshot to trap its prey.

This unusual method was studied up close for a recent paper published in the Proceedings of the National Academy of Sciences by researchers at the University of Akron in Ohio. They say it's the only known instance of an animal using an external device—its web—for power amplification.

Hyptiotes cavatus's technique is simple. After constructing a web, the spider takes one of the main strands and breaks it in half, pulling it taut by moving backwards. Then, it anchors itself to a spot with more webbing in the rear. When the spider releases that webbing, it surges forward, propelled by the sudden release of stored energy. In the slingshot analogy, the webbing is the strap and the spider is the projectile.

This jerking motion causes the web to oscillate, tangling the spider's prey further in silk. The spider can repeat this until the web has completely immobilized its prey, a low-risk entrapment that doesn’t require the spider to get too close and risk injury from larger victims.

The triangle weaver spider doesn’t have venom, and it needs to be proactive in attacking and stifling prey. Once a potential meal lands in its web, it’s able to clear distances much more quickly using this slingshot technique than if it crawled over. In the lab, scientists clocked the spider’s acceleration at 2535 feet per second squared.

Spiders are notoriously nimble and devious. Cebrennus rechenbergi, or the flic-flac spider, can do cartwheels to spin out of danger; Myrmarachne resemble ants and even wiggle their front legs like ant antennae. It helps them avoid predators, but if they see a meal, they’ll drop the act and pounce. With H. cavatus, it now appears they’re learning to use tools, too.

[h/t Live Science]

Bad News: The Best Time of the Day to Drink Coffee Isn’t as Soon as You Wake Up

iStock.com/ThomasVogel
iStock.com/ThomasVogel

If you depend on coffee to help get you through the day, you can rest assured that you’re not the world's only caffeine fiend. Far from it. According to a 2018 survey, 64 percent of Americans said they had consumed coffee the previous day—the highest percentage seen since 2012.

While we’re collectively grinding more beans, brewing more pots, and patronizing our local coffee shops with increased frequency, we might not be maximizing the health and energy-boosting benefits of our daily cup of joe. According to Inc., an analysis of 127 scientific studies highlighted the many benefits of drinking coffee, from a longer average life span to a reduced risk for cancer, heart disease, type 2 diabetes, and Parkinson’s disease.

Sounds great, right? The only problem is that the benefits of coffee might be diminished depending on the time of day that you drink it. Essentially, science tells us that it’s best to drink coffee when your body’s cortisol levels are low. That’s because both caffeine and cortisol cause a stress response in your body, and too much stress is bad for your health for obvious reasons. In addition, it might end up making you more tired in the long run.

Cortisol, a stress hormone, is released in accordance with your circadian rhythms. This varies from person to person, but in general, someone who wakes up at 6:30 a.m. would see their cortisol levels peak in different windows, including 8 to 9 a.m., noon to 1 p.m., and 5:30 to 6:30 p.m. Someone who rises at 10 a.m. would experience cortisol spikes roughly three hours later, and ultra-early risers can expect to push this schedule three hours forward.

However, these cortisol levels start to rise as soon as you start moving in the morning, so it isn’t an ideal time to drink coffee. Neither is the afternoon, because doing so could make it more difficult to fall asleep at night. This means that people who wake up at 6:30 a.m. should drink coffee after that first cortisol window closes—roughly between 9:30 a.m. and 11:30 a.m.—if they want to benefit for a little caffeine jolt.

To put it simply: "I would say that mid-morning or early afternoon is probably the best time," certified dietitian-nutritionist Lisa Lisiewski told CNBC. "That's when your cortisol levels are at their lowest and you actually benefit from the stimulant itself."

[h/t Inc.]

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