Our Microbial Puppetmasters
Carl Zimmer writes in The New York Times about a fascinating new paper by Athena Aktipis and her colleagues on how our gastrointestinal microbes may be manipulating us:
We've come to appreciate how beneficial our microbes are -- breaking down our food, fighting off infections and nurturing our immune system. It's a lovely, invisible garden we should be tending for our own well-being.But in the journal Bioessays, a team of scientists has raised a creepier possibility. Perhaps our menagerie of germs is also influencing our behavior in order to advance its own evolutionary success -- giving us cravings for certain foods, for example.
Maybe the microbiome is our puppet master.
"One of the ways we started thinking about this was in a crime-novel perspective," said Carlo C. Maley, an evolutionary biologist at the University of California, San Francisco, and a co-author of the new paper. "What are the means, motives and opportunity for the microbes to manipulate us? They have all three."
...How parasites control their hosts remains mysterious. But it looks as if they release molecules that directly or indirectly can influence their brains.
...Different species of microbes thrive on different kinds of food. If they can prompt us to eat more of the food they depend on, they can multiply.
Microbial manipulations might fill in some of the puzzling holes in our understandings about food cravings, Dr. Maley said.
...Take chocolate: Many people crave it fiercely, but it isn't an essential nutrient. And chocolate doesn't drive people to increase their dose to get the same high. "You don't need more chocolate at every sitting to enjoy it," Dr. Maley said.
Perhaps, he suggests, the certain kinds of bacteria that thrive on chocolate are coaxing us to feed them.
The abstract of the paper, published in BioEssays:
Is eating behavior manipulated by the gastrointestinal microbiota? Evolutionary pressures and potential mechanismsMicrobes in the gastrointestinal tract are under selective pressure to manipulate host eating behavior to increase their fitness, sometimes at the expense of host fitness. Microbes may do this through two potential strategies: (i) generating cravings for foods that they specialize on or foods that suppress their competitors, or (ii) inducing dysphoria until we eat foods that enhance their fitness. We review several potential mechanisms for microbial control over eating behavior including microbial influence on reward and satiety pathways, production of toxins that alter mood, changes to receptors including taste receptors, and hijacking of the vagus nerve, the neural axis between the gut and the brain. We also review the evidence for alternative explanations for cravings and unhealthy eating behavior. 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.
Authors: Joe Alcock, Carlo C. Maley, and C. Athena Aktipis.
So what makes the germs decide to give me gas when I eat green peppers? ;-b
jdgalt at August 16, 2014 11:30 PM
https://www.youtube.com/watch?v=XuKjBIBBAL8
lujlp at August 16, 2014 11:46 PM
https://www.youtube.com/watch?v=63IDKUbh8kI
lujlp at August 16, 2014 11:52 PM
https://www.youtube.com/watch?v=Go_LIz7kTok
lujlp at August 16, 2014 11:56 PM
https://www.youtube.com/watch?v=VfXS0KQmN_I
lujlp at August 17, 2014 12:01 AM
Theres more, but it just gets scarier from their
lujlp at August 17, 2014 12:02 AM
I have feelings for Bonnie Bassler.
Strong, masculine feelings...
http://www.ted.com/talks/bonnie_bassler_on_how_bacteria_communicate
crid at August 17, 2014 12:04 AM
Another way to escape the blame for a lot of us.
How do those little bastards know when to crank up the internal pressure (so to speak) **just** as some pleasant looking female gets on the treadmill next to me???
drcos at August 17, 2014 4:36 AM
Huh. I thought it was already widely accepted that an overgrowth of yeast in the intestines (usually related to antibiotic use) would produce wild sugar cravings because yeast need sugar. More or less the same thin, right?
Jenny had a chance at August 17, 2014 4:58 AM
Anyone interested in this topic is likely to enjoy the novel Parasite by Mira Grant. It's up for a Hugo (it won't win, as it's up against the Wheel of Time series juggernaut, but still, it's been nominated). The author has clearly done a LOT of research on the topic. Sequel is coming out soon, too.
I'd type more, but I'm suddenly craving chocolate...
marion at August 17, 2014 5:58 AM
Does this explain why whole families are liberal? Or conservative? Fungal capture.
Andrew_M_Garland at August 17, 2014 7:34 AM
Wow, luj, Crid, marion...great additions to the post.
And Andrew, actually, there are a number of papers tying belief systems to avoidance of parasites. In "Good Manners For Nice People Who Sometimes Say F*ck", I reference the work of Josh Tyber, Debra Lieberman, and Vlad Griskevicius on disgust -- the best on the subject (because Haidt and Rozin, et al have this nutty and unfounded theory about how we're disgusted because we don't want to be like the animals).
Amy Alkon at August 17, 2014 7:40 AM
Our government secrecy establishment has known how to use this for years.
jefe at August 17, 2014 1:52 PM
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