Science says your gut feeling is not a metaphor. It's your enteric nervous system, the second brain, and it affects memory in the brain.
Adam Rifkin stashed this in Microbiome
The enteric nervous system they form is so powerful that it can work without any direct input from the brain:
The processes the enteric nervous system performs also gives it some control over the trillions of microbes that sit in your gut. Many of them are essential for our health, because they help us extract nutrients that we wouldn’t otherwise be able to, and some even fend off infections.
One way enteric neurons control these microbes is by changing the thickness of the mucus lining. Justin and Erica Sonnenburg, researchers at Stanford University and authors of The Good Gut, say this process is similar to how “creatures adapted to a moist rain forest would struggle in the desert.” Depending on what kinds of microbes are best suited for a job, the mucus lining can determine their population in the gut.
We are hosts to our microbiome's collective.
It's the other way around, Adam – they're the majority and they're hosting us.
Yes but we are bigger and we surround them. Doesn't that make us host?
Well, I do know that they (our microbiome community) actually surround us and are located across all parts of us (internally and externally) and they also have far bigger numbers (10x to 100x) of residents living upon and within us than we have cells in our own body:
that kinda makes them host... if bigger and surrounded is how you roll hosting.
Suddenly I feel like we are not the most advanced organisms on this planet.
Their hive mind is way bigger than our hive mind.
It had been suspected that what happens in the gut could have an impact on the brain. Now we have found too many correlations to ignore the gut-to-brain connection.
A 2011 study split a group of mice based on their personality: timid vs adventurous. Then the researchers took another set of mice with microbe-free guts. In half, they installed the microbiome of timid mice, and in the other half they placed the microbiome of adventurous mice. Lo and behold those germ-free mice took on the personality traits of the microbiome-owner.
In a 2013 study, using another mice model, researchers at the California Institute of Technology found that mice with autistic features—such as stress, anti-social nature, and troubling gastrointestinal symptoms—had much lower levels of Bacteroides fragilis than normal mice did. Worse still, when injected a chemical (4-ethylphenylsulphate) found in the guts of autistic mice in to normal mice, they developed autistic symptoms too.
In a 2014 study, researchers at University College Cork found that mice born via C-sections were found to have a greater risk of suffering from depression than mice born vaginally. Turns out, the C-section mice had far less diverse species of microbes in their gut, most likely because they couldn’t pick up the beneficial microbes found in their mother’s vagina.
Although mice are easier to manipulate, such connections are not limited to mice alone. In a 2013 study, researchers at Arizona State University found that humans with behavioral conditions, such as autism, had significant differences in their gut microbiome as compared to more normal humans.
Until now, however, these gut-brain connections have been mere correlations. With some help from tapeworms, a new study changes that.
I quoted the tapeworm study below. The finding: Guts affect memory in the brain.
Our guts can significantly affect memory loss in the brain.
One of the connecting factors between the brain and the gut has been the immune system. Neurological diseases, such as Alzheimer’s and multiple sclerosis, are linked to changes in the immune system, and auto-immune diseases of the gut, such as Crohn’s disease, are linked to mental illnesses.
Now a new study published in published in Brain, Behavior and Immunity has made use of this immune-system connection to show how the gut can have an impact on the brain. To trigger this connection, Staci Bilbo, a neuroscientist at Duke University, and her colleagues used tapeworms and showed how these nasty creatures can stop memory loss.
She split a group of 30 rats in two: those infected with the Hymenolepis diminuta worm and those without. Then, in both groups, she induced a second infection aimed at increasing the production of a brain signaling chemical called IL-1β. The chemical is usually beneficial, but in excess it can cause damage and has been associated with brain disease.
To test their memories, the rats were put in a room and were allowed to become familiar with it. Then Bilbo gave them a shock so that they would connect the room with bad memories. The next day she re-introduced both wormed and un-wormed rats in the room.
She found that mice with tapeworms were twice as likely to recoil from the room as rats that did not have worms. So the tapeworm infection seems to have protected the mice from memory loss, as compared to infection-free mice.
The relationships between mind (brain) and body have long interested philosophers including Plato. Rene Descartes is well know for his thoughts on the "Mind-Body Problem" which is becoming especially relevant today as we consider the promise and threat of Artificial Intelligence" (AI).
As with the gut, we have historically viewed in brain as insulated, if not isolated, from the peripheral circulation by the Blood-Brain Barrier" (BBB). What goes on in the blood stays in the blood and the same for the brain. It is true that the BBB can be selective for certain molecules, a fact that poses special challenges to delivering drugs to treat brain dysfunctions. The BBB can also be opened by brain injury and disease. But we are beginning to understand that the BBB is much more dynamically regulated than we have previously recognized. Common events such as stress and exercise can open the BBB. To emphasize the intimate relationship between the brain and the cerebral circulation, many investigators (including me in a recent publication) are studying the brain as comprised of neurovascular and gliavascular units. The term BBB is a misnomer and is better understood as the Blood-Brain Portal, even if we have yet to identify all of the gate keepers.
Although certainly no expert, I frequently read discussions that focus on AI in the context of in silico computational speed and power. If our new insights into mind as residing in a much more expensive and liquid milieu than represented by computer circuitry, then achieving the goals of AI will require careful consideration of these recent observations by biological neuroscience. That said, I'm intrigued by Adam's recent post, "Model for robots with bacteria controlled brains". Is other work more systematically addressing these blood and guts questions?
Thank you for the reminder about that article, Ron.
I don't know of any other work systematically addressing these questions.
But I'm always keeping my eyes open for more at Ray Kurzweil's sites: