Do gut bacteria rule our minds? In an ecosystem within us, microbes evolved to sway food choices

It sounds like science fiction, but it seems that bacteria within us -- which outnumber our own cells about 100-fold -- may very well be affecting both our cravings and moods to get us to eat what they want, and often are driving us toward obesity.

In an article published this week in the journal BioEssays, researchers from UC San Francisco, Arizona State University and University of New Mexico concluded from a review of the recent scientific literature that microbes influence human eating behavior and dietary choices to favor consumption of the particular nutrients they grow best on, rather than simply passively living off whatever nutrients we choose to send their way.

Bacterial species vary in the nutrients they need. Some prefer fat, and others sugar, for instance. But they not only vie with each other for food and to retain a niche within their ecosystem -- our digestive tracts -- they also often have different aims than we do when it comes to our own actions, according to senior author Athena Aktipis, PhD, co-founder of the Center for Evolution and Cancer with the Helen Diller Family Comprehensive Cancer Center at UCSF.

While it is unclear exactly how this occurs, the authors believe this diverse community of microbes, collectively known as the gut microbiome, may influence our decisions by releasing signaling molecules into our gut. Because the gut is linked to the immune system, the endocrine system and the nervous system, those signals could influence our physiologic and behavioral responses.

"Bacteria within the gut are manipulative," said Carlo Maley, PhD, director of the UCSF Center for Evolution and Cancer and corresponding author on the paper." "There is a diversity of interests represented in the microbiome, some aligned with our own dietary goals, and others not."

Fortunately, it's a two-way street. We can influence the compatibility of these microscopic, single-celled houseguests by deliberating altering what we ingest, Maley said, with measurable changes in the microbiome within 24 hours of diet change.

"Our diets have a huge impact on microbial populations in the gut," Maley said. "It's a whole ecosystem, and it's evolving on the time scale of minutes."

There are even specialized bacteria that digest seaweed, found in humans in Japan, where seaweed is popular in the diet.

Research suggests that gut bacteria may be affecting our eating decisions in part by acting through the vagus nerve, which connects 100 million nerve cells from the digestive tract to the base of the brain.

"Microbes have the capacity to manipulate behavior and mood through altering the neural signals in the vagus nerve, changing taste receptors, producing toxins to make us feel bad, and releasing chemical rewards to make us feel good," said Aktipis, who is currently in the Arizona State University Department of Psychology.

In mice, certain strains of bacteria increase anxious behavior. In humans, one clinical trial found that drinking a probiotic containing Lactobacillus casei improved mood in those who were feeling the lowest.

Maley, Aktipis and first author Joe Alcock, MD, from the Department of Emergency Medicine at the University of New Mexico, proposed further research to test the sway microbes hold over us. For example, would transplantation into the gut of the bacteria requiring a nutrient from seaweed lead the human host to eat more seaweed?

The speed with which the microbiome can change may be encouraging to those who seek to improve health by altering microbial populations. This may be accomplished through food and supplement choices, by ingesting specific bacterial species in the form of probiotics, or by killing targeted species with antibiotics. Optimizing the balance of power among bacterial species in our gut might allow us to lead less obese and healthier lives, according to the authors.

"Because microbiota are easily manipulatable by prebiotics, probiotics, antibiotics, fecal transplants, and dietary changes, altering our microbiota offers a tractable approach to otherwise intractable problems of obesity and unhealthy eating," the authors wrote.

The authors met and first discussed the ideas in the BioEssays paper at a summer school conference on evolutionary medicine two years ago. Aktipis, who is an evolutionary biologist and a psychologist, was drawn to the opportunity to investigate the complex interaction of the different fitness interests of microbes and their hosts and how those play out in our daily lives. Maley, a computer scientist and evolutionary biologist, had established a career studying how tumor cells arise from normal cells and evolve over time through natural selection within the body as cancer progresses.

In fact, the evolution of tumors and of bacterial communities are linked, points out Aktipis, who said some of the bacteria that normally live within us cause stomach cancer and perhaps other cancers.

"Targeting the microbiome could open up possibilities for preventing a variety of disease from obesity and diabetes to cancers of the gastro-intestinal tract. We are only beginning to scratch the surface of the importance of the microbiome for human health," she said.

The co-authors' BioEssays study was funded by the National Institutes of Health, the American Cancer Society, the Bonnie D. Addario Lung Cancer Foundation and the Institute for Advanced Study, in Berlin.

Harnessing the power of bacteria's sophisticated immune system

Bacteria's ability to destroy viruses has long puzzled scientists, but researchers at the Johns Hopkins Bloomberg School of Public Health say they now have a clear picture of the bacterial immune system and say its unique shape is likely why bacteria can so quickly recognize and destroy their assailants.

The researchers drew what they say is the first-ever picture of the molecular machinery, known as Cascade, which stands guard inside bacterial cells. To their surprise, they found it contains a two-strand, unencumbered structure that resembles a ladder, freeing it to do its work faster than a standard double-helix would allow.

The findings, published online Aug. 14 in the journal Science, may also provide clues about the spread of antibiotic resistance, which occurs when bacteria adapt to the point where antibiotics no longer work in people who need them to treat infections, since similar processes are in play. The World Health Organization (WHO) considers antibiotic resistance a major threat to public health around the world.

"If you understand what something looks like, you can figure out what it does," says study leader Scott Bailey, PhD, an associate professor in the Bloomberg School's Department of Biochemistry and Molecular Biology. "And here we found a structure that nobody's ever seen before, a structure that could explain why Cascade is so good at what it does."

For their study, Bailey and his colleagues used something called X-ray crystallography to draw the picture of Cascade, a key component of bacteria's sophisticated immune system known as CRISPR, an acronym for Clustered Regularly Interspaced Short Palindromic Repeats. Cascade uses the information housed in sequences of RNA as shorthand to identify foreign invaders and kill them.

Much of the human immune system is well understood, but until recently scientists didn't realize the level of complexity associated with the immune system of single-cell life forms, including bacteria. Scientists first identified CRISPR several years ago when trying to understand why bacterial cultures used to make yogurt succumbed to viral infections. Researchers subsequently discovered they could harness the CRISPR bacterial immune system to edit DNA and repair damaged genes. One group, for example, was able to remove viral DNA from human cells infected with HIV.

Bailey's work is focused on how Cascade is able to help bacteria fight off viruses called bacteriophages. The Cascade system uses short strands of bacterial RNA to scan the bacteriophage DNA to see if it is foreign or self. If foreign, the cell launches an attack that chews up the invading bacteriophage.

To "see" how this happens, Bailey and his team converted Cascade into a crystalized form. Technicians at the National Synchrotron Light Source at Brookhaven National Laboratory in Upton, NY, and the Stanford Synchrotron Radiation Lightsource then trained high-powered X-rays on the crystals. The X-rays provided computational data to the Bloomberg School scientists allowing them to draw Cascade, an 11-protein machine that only operates if each part is in perfect working order.

What they saw was unexpected. Instead of the RNA and DNA wrapping around each other to form what is known as a double-helix structure, in Cascade the DNA and RNA are more like parallel lines, forming something of a ladder. Bailey says that if RNA had to wrap itself around DNA to recognize an invader -- and then unwrap itself to look at the next strand -- the process would take too much time to ward off infection. With a ladder structure, RNA can quickly scan DNA.

In the new study, Bailey says his team determined that the RNA scans the DNA in a manner similar to how humans scan text for a key word. They break long stretches of characters into smaller bite-sized segments, much like words themselves, so they can be spotted more easily.

Since the CRISPR-Cas system naturally acts as a barrier to the exchange of genetic information between bacteria and bacteriophages, its function can offer clues to how antibiotic resistance develops and ideas for how to keep it from happening.

"We're finding more pieces to the puzzle," Bailey says. "This gives us a better understanding of how these machines find their targets, which may help us harness the CRISPR system as a tool for therapy or manipulation of DNA in a lab setting. And it all started when someone wanted to make yogurt more cheaply."

"Crystal structure of a CRISPR RNA-guided surveillance complex bound to a ssDNA target," was written by Sabin Mulepati, Annie Heroux and Scott Bailey.

Hoopoes' eggs show their true colors

Hoopoe females use cosmetics on their eggs -- and the eggs gradually change color when they are incubated, from bluish-grey to a more saturated greenish-brown. This happens because secretion from the uropygial or preen gland -- a substance birds use to preen and protect their feathers -- is transfered from the female hoopoe's gland to her eggs directly with the bill and by means of belly feathers. This is one of the findings from a study led by Juan J. Soler of the Estación Experimental de Zonas Áridas, CSIC in Spain, published in Springer's journal Naturwissenschaften -- The Science of Nature.

Previous work by Soler´s team has shown that the preen gland secretion of incubating hoopoes is brown in color and holds antimicrobial properties. The color is thanks to a combination of symbiotic bacteria found in the uropygial gland that provides protection against pathogenic bacteria. The symbiotic bacteria help to protect embryos from trans-shell infections, and in vitro are highly effective against Bacillus licheniformis, a well-known feather-degrading bacterium. The darker the color of the secretion, the more of the "good" bacteria are present -- and the better protection there is against the "bad" bacteria to ensure that a bird's embryos or feathers stay healthy.

To find out if indeed it is the gland secretion that causes hoopoes' eggs to change color, Soler's team conducted field studies in southern Spain and experimental work at the University of Granada and in Finca Experimental la Hoya in Almeria. In some cases, the researchers blocked off female hoopoes' uropygial glands found over their tails, to make it impossible for them to spread any preen oil onto their feathers or eggs. In other instances, the researchers smeared eggshells with this preen oil.

Their experimental tests showed that eggs that came into contact with the gland secretion changed color from their initial bluish-grey to greenish-brown. Eggs that were not covered with this so-called preen oil showed no color change.

"The eggshell coloration of hoopoe eggs is the consequence of the female birds' spreading uropygial secretion on the eggshells," says Soler.

The researchers speculate that the egg coloration might be a way through which a female hoopoe signals to the male that she is good breeding material, for future reference. It can inform a male of the presence, abundance, or even particularities of the antimicrobial bacterial community found in a female's glands -- qualities that she will be able to carry over to their offspring should they mate in the future. Males can use this information to adjust their investment in the actual breeding attempt. Although further experimental work is needed to establish the validity of this signaling hypothesis, Soler hopes that the new results will encourage such research in hoopoes and in other birds.

Story Source:

The above story is based on materials provided by Springer Science+Business Media . Note: Materials may be edited for content and length.

A 1996 Plan to Use NASA’s Oldest Orbiter to Make Money on the Moon

NASA

Assembly of NASA’s first spaceworthy Space Shuttle Orbiter, OV-102 Columbia, commenced in March 1975. The 111-ton reusable winged spaceship first reached low-Earth orbit on STS-1 (12-14 April 1981), the Space Shuttle Program’s first mission. Named for the first American sailing ship to circle the globe and the Apollo 11 Command and Service Module, Columbia completed 27 successful flights.

NASA’s oldest Orbiter was also its heaviest. Unlike its sisters Atlantis, Discovery, and Endeavor, Columbia had difficulty reaching the 51.6° orbital inclination of the Russian Mir station and the International Space Station (ISS) with a useful payload in its 15-by-60-foot payload bay. It was the only Orbiter that did not visit the Russian Mir station. This performance constraint meant that, in the Shuttle-Mir/ISS era, NASA relegated to Columbia its few remaining low-inclination, non-space station missions, such as Hubble Space Telescope servicing.

Extended-Duration Orbiter modifications would permit Columbia to remain in orbit for more than two weeks to serve as a science research platform. Such missions would, however, become increasingly rare – or end entirely – as research expanded on board ISS.

In an April 1996 paper presented at the 33rd Space Congress in Cocoa Beach, Florida, Carey McCleskey of the Vehicle Engineering Directorate at NASA’s Kennedy Space Center proposed using the oldest Orbiter’s excess mission capacity “to ignite a billion dollar, sustained enterprise on the Moon.” Specifically, he advocated using Columbia as a joint NASA/private sector Earth-orbital launch platform for rocket stages bearing small lunar landers. Columbia would remain in space for only a few hours during each of its lunar lander deployment missions.

The first Space Shuttle launch: Columbia lifts off at the start of STS-1 on 12 April 1981. NASA

The landers would deliver to the moon teleoperated “micro-robots” akin to Mars Pathfinder’s Sojourner minirover. These would serve as proxy lunar explorers for paying visitors at “space theme parks” on Earth.

Confident that his proposal would help to build public support for U.S. astronauts to return to the moon, McCleskey wrote that

use of Columbia only makes sense for the start-up and initial take-off phases of the enterprise. The Shuttle system. . .will reach a limit which will drive the nation toward advanced space delivery systems. The use of the Shuttle for starting a lunar enterprise, therefore, is not the answer for space delivery, but rather our next opportunity.

Columbia lifted off at the start of STS-107, its 28th mission, on 16 January 2003. Eighty-two seconds after launch, a piece of foam insulation about 20 inches long broke free from its External Tank and struck its left wing. Engineers examining high-resolution video images of the impact warned of possible wing damage, but Shuttle management elected to disregard their warnings.

The oldest Orbiter’s seven-person crew conducted wide-ranging science research for 16 days – long enough for the moon to wax from nearly full to full, then wane to last quarter and new. The crew beamed to Earth a breathtaking image of the last quarter moon taken on 26 January (image at top of post).

On 1 February 2003, the day of the new moon, Columbia fired its twin Orbital Maneuvering System engines to slow itself and reenter Earth’s atmosphere. Temperatures on the Orbiter’s belly tiles, nose cap, and wing leading edge panels began to climb as Columbia reentered at an altitude of 400,000 feet. About 40 minutes after the deorbit burn the wing leading edge temperature neared its peak value of about 3000° Fahrenheit.

As Columbia crossed the California coast in predawn darkness en route to its planned landing in Florida, hot plasma began to penetrate its internal structure through a breach in its left wing leading edge. Flight controllers in Mission Control in Houston puzzled over the cause of sensor failures in the Orbiter’s left wing. The failures progressed aftward from the leading edge.

For observers on the ground in California, Nevada, Utah, Arizona, Colorado, New Mexico, and Texas, many of whom had observed pre-dawn Shuttle reentries before, Columbia was a fast-moving, brilliant point of light leaving behind a luminous, sky-spanning ionization trail. Veteran observers along Columbia‘s reentry path noted more than 20 unusual flashes around the Orbiter and peculiar bright streaks in the trail.

As Columbia crossed from New Mexico into Texas, it began to shed pieces. Meanwhile, thrusters fired automatically to compensate for increased drag on the left wing. Columbia did not give up without a fight.

Radio contact with Columbia was lost about 10 minutes after hot plasma first entered the left wing. Less than a minute later, the gutted wing folded over the fuselage. The oldest Orbiter tumbled and disintegrated at an altitude of 203,000 feet just west of Dallas, Texas, killing its crew and raining wreckage over parts of eastern Texas and western Louisiana.

Had Columbia not been destroyed, NASA would have launched it to the ISS for the first (and probably only) time in November 2003. The STS-118 mission would have seen NASA’s oldest Orbiter stand in for its younger sister Discovery, which was scheduled for periodic maintenance. As it turned out, Endeavour, the Orbiter built to replace Challenger, carried out STS-118 in August 2007. Columbia was the only Orbiter that never visited a space station.

The STS-107 accident triggered far-reaching changes in the U.S. space program that even now have yet to play out fully. Most obvious of these was President George W. Bush’s January 2004 call to end the Space Shuttle Program when ISS was completed, which at the time was scheduled for 2010. The 135th and last flight of the Shuttle, designated STS-135, concluded on 21 July 2011, with the landing of Atlantis in Florida. On 16 August 2011, Space Shuttle Program Manager John Shannon announced that the Shuttle Program would end officially on 31 August 2011.

Reference

“Using the Space Shuttle Columbia to Begin Bringing the Moon to America,” Carey M. McCleskey; paper presented at the 33rd Space Congress in Cocoa Beach, Florida, April 23-26, 1996.

Related Beyond Apollo Posts

Space Station Columbia (1991)

Columbia, Discovery, and Atlantis

Ten Years After Columbia: A List of Shuttle-Station Posts

Game|Life Podcast: Sony, Microsoft Trade Exclusives In Germany

Concept artwork from Rise of the Tomb Raider. Square Enix

We discuss Sony’s and Microsoft’s announcements at Gamescom, Europe’s big gaming trade and consumer show, on this week’s Game|Life Podcast.

Microsoft certainly riled up some fans with the news that Rise of the Tomb Raider, pictured above, would be exclusive to the Xbox One. Apparently, this will only be for a specified period of time, so it’s highly likely that PlayStation 4 will also be graced with Lara Croft’s presence at some point. But if you want to play her latest adventure the day it comes out, you’ll need to own an Xbox One. Console wars are tough things, kids. This is the topic of our discussion on the podcast, and Peter Rubin and Bo Moore join me to chat about exclusives and other announcements.

Bo gives us more thoughts on Firefall , and I talk about my recent piece on the Night Trap Kickstarter, too. Enjoy!

Game|Life’s podcast is posted on Fridays, is available on iTunes, can be downloaded directly and is embedded below.

[dewplayer: http://ift.tt/1vSxym9]

The Internet Is Now Officially More Popular Than Cable in the U.S.

Ariel Zambelich/WIRED

You can’t call them “cable companies” anymore.

For the first time, the number of broadband subscribers with the major US cable companies exceeded the number of cable subscribers, the Leichtman Research Group reported today. Among other things, these figures suggest the industry is now misnamed. Evidently these are broadband companies that offer cable on the side.

To be sure, the difference is minimal: 49,915,000 broadband subscribers versus 49,910,000 cable subscribers. But even assuming a huge overlap in those numbers from customers who have both, the primacy of broadband demonstrates a shift in consumer priorities. Nearly all the major cable companies added broadband subscribers over the past quarter, for a total of nearly 380,000 new signups. Cable subscribers don’t have to worry about TV as they know it going away any time soon. But cable is on its way to becoming secondary, the “nice to have” compared to the necessity of having broadband access.

Not Bad for Business

Such a transition might suit the “cable companies” just fine. I first saw these numbers pointed out by Peter Kafka at Recode, who wrote: “Some smart people suggest that the cable guys would not be unhappy if most of their business moved over to broadband instead of video, since there are much better margins—and almost no competition—for broadband.”

The better margins boil down to the fact that broadband is purely about access, while cable is about content. The crux of the cable side of the cable business is hatching deals with the makers of sports, news, and entertainment so there’s something to send through the box. And the costs can be steep. ESPN, the most pricey by far, tops $5 per subscriber per month.

With broadband, the cable companies don’t have to put anything through those pipes themselves. They just have to be the plumbers. They may not like the way Netflix and its more than 36 million U.S. subscribers are eating into their TV businesses. But Netflix and other streaming services are helping drive demand for broadband—a service cable operators can provide without having to serve up any content themselves at all.

TV’s Broad Future

What this means for the future of TV is still tough to predict. While these figures may suggest the inevitable transition to an internet-dominated future, nearly 50 million cable subscribers don’t appear ready to cut the cord just yet. Even with a plethora of on-demand options, people are still watching TV like they used to, which means a business model still based around ads and subscription fees. But that’s still a loss of millions of cable subscribers over the past half-decade, while the number of broadband subscribers has climbed at a much faster clip.

Meanwhile, traditional TV as a format already is being engulfed by the open-endedness of the internet. From mainstream streaming services like Netflix, Hulu, and Amazon Instant Video to niche sites like Funny or Die to YouTube celebrities—to name just some of the options that fall under entertainment—the kinds of moving pictures available and the ways to consume them have never been greater. Within this broader spectrum, cable as a concept could become just another niche, one channel among many as the insatiable internet swallows everything it encounters.

What to Do in Honolulu if You Hate Surfing

Just 30 minutes from downtown Honolulu, Makapuu beach offers some of the best bodysurfing in the world. Marco Garcia

Every August, Honolulu's premier ocean sports event kicks off on Waikiki Beach. It's Duke's Ocean-Fest, a nine-day tournament with events like tandem surfing, paddleboard racing, and surf polo—water polo on longboards! More than 2,000 athletes from Australia, Japan, New Zealand, and the US compete. Now in its 13th year, the festival honors Duke Kahanamoku, Hawaii's famed Olympic gold medalist and aloha ambassador, who died in 1968. “He helped pioneer and expand surfing to the rest of the world,” says event director Brent Imonen. Which means the Duke also helped fuel a whopping industry: Surfing looks likely to reach $13 billion in global revenue by 2017.

Waikiki Aquarium This 110-year-old aquarium has the only peppermint angelfish on public display in the world—the rare striped critter is worth over $30,000.

Atlantis Premium Sub Tours Board the 64-passenger Atlantis XIV, the world's largest high tech passenger sub, and descend 100 feet to visit shipwrecks and coral reefs.

EVERETT COLLECTION

Oahu Nature Tours A rain forest walkabout takes you to some filming locations of Jurassic Park.

Nocturna Lounge This classed-up bar-cade offers gaming tournaments—from Street Fighter to Marvel vs. Capcom—as well as karaoke.

Hawaii Shark Encounters Dip into shark-infested waters: Only a 1/4-inch-thick Polyglass window separates you from dozens of Galapagos and sandbar sharks.

Honolulu Fish Auction Get up at the crack of dawn to watch top restaurant chefs bid for killer fresh ahi.

MARCO GARCIA

Leonard's Bakery For more than 60 years, Leonard's has been serving up Portuguese doughnuts called malasadas. Also try the pão doce.

Pint + Jigger Go for the craft beer but stay for this gastropub's eats, like marlin maque choux and bacon-and-brandy-covered strawberries.

Justin Mezzel