Her parents were running out of hope. Their teenage daughter, Mary,
had been diagnosed with a severe case of obsessive–compulsive
disorder (OCD), as well as ADHD. They had dragged her to clinics
around the country in an effort to thwart the scary, intrusive thoughts
and the repetitive behaviors that Mary felt compelled to perform.
Even a litany of psychotropic medications didn’t make much
difference. It seemed like nothing could stop the relentless nature
of Mary’s disorder.
had been diagnosed with a severe case of obsessive–compulsive
disorder (OCD), as well as ADHD. They had dragged her to clinics
around the country in an effort to thwart the scary, intrusive thoughts
and the repetitive behaviors that Mary felt compelled to perform.
Even a litany of psychotropic medications didn’t make much
difference. It seemed like nothing could stop the relentless nature
of Mary’s disorder.
Their last hope for Mary was Boston-area psychiatrist James
Greenblatt. Arriving at his office in Waltham, MA, her parents had
only one request: help us help Mary.
Greenblatt. Arriving at his office in Waltham, MA, her parents had
only one request: help us help Mary.
Greenblatt started by posing the usual questions about Mary’s
background, her childhood, and the onset of her illness. But then he
asked a question that no psychiatrist ever had: How was Mary’s gut?
Did she suffer digestive upset? Constipation or diarrhea? Acid reflux?
Had Mary’s digestion seemed to change at all before or during her
illness? Her parents looked at each other. The answer to many of the
doctor’s questions was, indeed, “Yes.”
That’s what prompted Greenblatt to take a surprising approach:
besides psychotherapy and medication, Greenblatt also prescribed
Mary a twice-daily dose of probiotics, the array of helpful bacteria that
lives in our gut. The change in Mary was nothing short of miraculous:
within six months, her symptoms had greatly diminished. One year after
the probiotic prescription, there was no sign that Mary had ever been ill.
besides psychotherapy and medication, Greenblatt also prescribed
Mary a twice-daily dose of probiotics, the array of helpful bacteria that
lives in our gut. The change in Mary was nothing short of miraculous:
within six months, her symptoms had greatly diminished. One year after
the probiotic prescription, there was no sign that Mary had ever been ill.
Her parents may have been stunned, but to Greenblatt, Mary’s case was
an obvious one. An imbalance in the microbes in Mary’s gut was either
contributing to, or causing, her mental symptoms. “The gut is really your
second brain,” Greenblatt said. “There are more neurons in the GI tract
than anywhere else except the brain.”
Greenblatt’s provocative idea — by targeting the digestive system
— is increasingly reinforced by cutting-edge science. For decades,
researchers have known of the connection between the brain and the
gut. Anxiety often causes nausea and diarrhea, and depression can
change appetite. The connection may have been established, but
scientists thought communication was one way: it traveled from the
brain to the gut, and not the other way around.
an obvious one. An imbalance in the microbes in Mary’s gut was either
contributing to, or causing, her mental symptoms. “The gut is really your
second brain,” Greenblatt said. “There are more neurons in the GI tract
than anywhere else except the brain.”
Greenblatt’s provocative idea — by targeting the digestive system
— is increasingly reinforced by cutting-edge science. For decades,
researchers have known of the connection between the brain and the
gut. Anxiety often causes nausea and diarrhea, and depression can
change appetite. The connection may have been established, but
scientists thought communication was one way: it traveled from the
brain to the gut, and not the other way around.
But now, a new understanding of the trillions of microbes
living in our guts reveals that this communication process
is more like a multi-lane superhighway than a one-way street.
By showing that changing bacteria in the gut can change
behavior, this new research might one day transform the way
we understand — and treat — a variety of mental health
disorders.
Greenblatt’s solution might strike us as simple, but he’s
actually targeting a vast, complex, and mysterious realm
of the human body: around 90 percent of our cells are
actually bacterial, and bacterial genes outnumber human
genes by a factor of 99 to 1. But those bacteria, most of
which perform helpful functions, weren’t always with us:
a baby is essentially sterile until it enters the birth canal,
at which point the bacteria start to arrive — and they
don’t stop. From a mother’s vaginal microbes to hugs
and kisses from relatives, the exposures of newborns
and toddlers in their earliest years is critical to the
development of a robust microbiome. For Greenblatt,
this radical treatment protocol has actually been decades
in the making. Even during his psychiatric residency at
George Washington University, he was perplexed by the
way mental disorders were treated. It was as if, he said,
the brain was totally separate from the body. More than 20
years of work treating eating disorders emphasized
Greenblatt’s hunch: that the connection between body and
mind was more important than conventional psychiatry
assumed. “Each year, I get more and more impressed at
how important the GI tract is for healthy mood and the
controlling of behavior,” Greenblatt said. Among eating
disorder patients, Greenblatt found that more than half of
psychiatric complaints were associated with problems in
the gut — and in some patients, he says he has remedied
both using solely high-dose probiotics, along with
normalizing eating.
GREENBLATT'S ACTUALLY TARGETING A VAST, COMPLEX, AND MYSTERIOUS REALM OF THE HUMAN BODY
In fact, recent research
suggests that early
microbiome development
might play a key role
in at least some aspects
of one’s adult mental
health. One 2011 study
out of McMaster
University compared the
behaviors of normal
eight-week-old mice and
mice whose guts were
stripped of microbes.
Bacteria-free mice exhibited higher levels of risk-taking, and
neurochemical analysis revealed higher levels of the stress
hormone cortisol and altered levels of the brain chemical
BDNF, which has been implicated in human anxiety and
depression. “This work showed us that anxiety was normal,
and that the gut-brain axis was involved in that,” Jane Foster,
the study’s lead author, said.
“Everybody knew that stress and anxiety could lead to
gastrointestinal symptoms, but we looked at it from the
bottom up and showed that the gut could communicate with
the brain. It was the first demonstration that the gut itself
could influence brain development.”
suggests that early
microbiome development
might play a key role
in at least some aspects
of one’s adult mental
health. One 2011 study
out of McMaster
University compared the
behaviors of normal
eight-week-old mice and
mice whose guts were
stripped of microbes.
Bacteria-free mice exhibited higher levels of risk-taking, and
neurochemical analysis revealed higher levels of the stress
hormone cortisol and altered levels of the brain chemical
BDNF, which has been implicated in human anxiety and
depression. “This work showed us that anxiety was normal,
and that the gut-brain axis was involved in that,” Jane Foster,
the study’s lead author, said.
“Everybody knew that stress and anxiety could lead to
gastrointestinal symptoms, but we looked at it from the
bottom up and showed that the gut could communicate with
the brain. It was the first demonstration that the gut itself
could influence brain development.”
Subsequent research out of McMaster further enforces those
findings, by showing that swapping one mouse’s gut
bacteria with that of another can significantly alter behavior.
Researchers transplanted microbes from one group of mice,
which were characterized by timidity, into the guts of mice
who tended to take more risks. What they observed was a
complete personality shift: timid mice became outgoing,
while outgoing mice became timid. “It’s good evidence that
the microbiota houses these behaviors,” Foster said.
findings, by showing that swapping one mouse’s gut
bacteria with that of another can significantly alter behavior.
Researchers transplanted microbes from one group of mice,
which were characterized by timidity, into the guts of mice
who tended to take more risks. What they observed was a
complete personality shift: timid mice became outgoing,
while outgoing mice became timid. “It’s good evidence that
the microbiota houses these behaviors,” Foster said.
While researchers have established a compelling link
between gut bacteria and mental health, they’re still trying
to figure out the extent to which the human microbiome
— once it’s populated in early childhood — can be
transformed. “The brain seems to be hardwired for anxiety
by puberty and early adolescence,” Foster said. If the
microbiome is part of that hardwiring, then it would
suggest that once we pass a certain threshold, the impact
of bacterial tweaks on problems like depression and
anxiety might wane.
between gut bacteria and mental health, they’re still trying
to figure out the extent to which the human microbiome
— once it’s populated in early childhood — can be
transformed. “The brain seems to be hardwired for anxiety
by puberty and early adolescence,” Foster said. If the
microbiome is part of that hardwiring, then it would
suggest that once we pass a certain threshold, the impact
of bacterial tweaks on problems like depression and
anxiety might wane.
In one Japanese study, for instance, researchers were only
able to change the baseline stress characteristics of
germ-free mice until nine weeks of age. After that, no
variety of bacterial additions to the mice’s guts could
properly regulate stress and anxiety levels. The explanation
for this phenomenon might lie in what’s known as
“developmental programming” — the idea that various
environmental factors, to which we’re exposed early on,
greatly determine the structure and function of organs
including the gut and the brain.
able to change the baseline stress characteristics of
germ-free mice until nine weeks of age. After that, no
variety of bacterial additions to the mice’s guts could
properly regulate stress and anxiety levels. The explanation
for this phenomenon might lie in what’s known as
“developmental programming” — the idea that various
environmental factors, to which we’re exposed early on,
greatly determine the structure and function of organs
including the gut and the brain.
“There are changes that happen early in life that we can’t
reverse,” said John Cryan, a neuroscientist at the University
of Cork in Ireland and a main investigator at the Alimentary
Pharmabiotic Centre. “But there are some changes that we
can reverse. It tells us that there is a window when microbes
are having their main effects and, until this closes, many
changes can be reversed.”
reverse,” said John Cryan, a neuroscientist at the University
of Cork in Ireland and a main investigator at the Alimentary
Pharmabiotic Centre. “But there are some changes that we
can reverse. It tells us that there is a window when microbes
are having their main effects and, until this closes, many
changes can be reversed.”
Even if our gut bacteria carries the biggest influence when
we’re young, experts like Greenblatt and Cryan are still
convinced that tweaking these bacteria later in life can yield
profound behavioral and psychological changes. In a study
led by Cryan, anxious mice dosed with the probiotic
bacterium Lactobacillus rhamnosus (JB-1) showed lower
levels of anxiety, decreased stress hormones, and even an
increase in brain receptors for a neurotransmitter that’s vital
in curbing worry, anxiety, and fear.
we’re young, experts like Greenblatt and Cryan are still
convinced that tweaking these bacteria later in life can yield
profound behavioral and psychological changes. In a study
led by Cryan, anxious mice dosed with the probiotic
bacterium Lactobacillus rhamnosus (JB-1) showed lower
levels of anxiety, decreased stress hormones, and even an
increase in brain receptors for a neurotransmitter that’s vital
in curbing worry, anxiety, and fear.
John Bienenstock, a co-author on that study, compared the
probiotics’ effects to benzodiazepines like Valium and
Xanax. “The similarity is intriguing. It doesn’t prove they
both use the same pathway [in the brain], but it’s a
possibility.”
probiotics’ effects to benzodiazepines like Valium and
Xanax. “The similarity is intriguing. It doesn’t prove they
both use the same pathway [in the brain], but it’s a
possibility.”
Although plenty of questions remain, the benefits of using
probiotics to treat human behavior are becoming
increasingly obvious. Yogurts like Danone’s Activia have
been marketed with much success as a panacea for all of
our intestinal ills. Other probiotic supplements have
claimed to support immune health. Probiotics’ potential to
treat human behavior is increasingly apparent, but will
manufacturers one day toss an anxiety-fighting blend into
their probiotic brews?
EXPERTS ARE
CONVINCED THAT
TWEAKING THESE
probiotics to treat human behavior are becoming
increasingly obvious. Yogurts like Danone’s Activia have
been marketed with much success as a panacea for all of
our intestinal ills. Other probiotic supplements have
claimed to support immune health. Probiotics’ potential to
treat human behavior is increasingly apparent, but will
manufacturers one day toss an anxiety-fighting blend into
their probiotic brews?
EXPERTS ARE
CONVINCED THAT
TWEAKING THESE
BACTERIA LATER IN
LIFE CAN YIELD
PROFOUND
BEHAVIORAL AND
PSYCHOLOGICAL
CHANGES
It’s a distinct possibility: in one 2013 proof-of-concept study,
researchers at UCLA showed that healthy women who
consumed a drink with four added probiotic strains twice
daily for four weeks showed significantly altered brain
functioning on an MRI brain scan. The women’s brains were
scanned while they looked at photos of angry or sad faces,
and then asked to match those with other faces showing
similar emotions.
researchers at UCLA showed that healthy women who
consumed a drink with four added probiotic strains twice
daily for four weeks showed significantly altered brain
functioning on an MRI brain scan. The women’s brains were
scanned while they looked at photos of angry or sad faces,
and then asked to match those with other faces showing
similar emotions.
Those who had consumed the probiotic drink showed
significantly lower brain activity in the neural networks that
help drive responses to sensory and emotional behavior.
The research is “groundbreaking,” Cryan said, because
it’s the first trial to show that probiotics could affect the
functioning of the human brain. Still, he notes that the
results need to be interpreted with care.
significantly lower brain activity in the neural networks that
help drive responses to sensory and emotional behavior.
The research is “groundbreaking,” Cryan said, because
it’s the first trial to show that probiotics could affect the
functioning of the human brain. Still, he notes that the
results need to be interpreted with care.
As the research community increasingly lends credence
to Greenblatt’s ideas, and public awareness about gut
bacteria grows, he’s confident we’ll soon know more
about the power of probiotics. “Because of the
commercials and the other information that’s out there,
patients are beginning to ask,” he said. “They’re much
more aware of how important probiotics are.”
to Greenblatt’s ideas, and public awareness about gut
bacteria grows, he’s confident we’ll soon know more
about the power of probiotics. “Because of the
commercials and the other information that’s out there,
patients are beginning to ask,” he said. “They’re much
more aware of how important probiotics are.”
Whether all of our mental woes respond to probiotic
treatment as dramatically as Greenblatt’s patient Mary
remains to be seen. “We have to be very cautious in
this field not to be too hyperbolic about what we
promise,” Cryan said. Indeed, scientists still aren’t sure
exactly which microbial species are part of a healthy
microbiome, nor do they know whether certain bacterial
strains are absolutely vital to mental functioning, or
whether the right balance is what’s key. Furthermore,
research still hasn’t parsed which illnesses might be
affected by the microbiome and, therefore, treatable
using probiotics. “There are beginning to be
suggestions that this type of probiotic treatment is
worth pursuing,” Bienenstock said. “Whether we can
use this to improve people’s lives, well, the door is
just beginning to open on this.”
treatment as dramatically as Greenblatt’s patient Mary
remains to be seen. “We have to be very cautious in
this field not to be too hyperbolic about what we
promise,” Cryan said. Indeed, scientists still aren’t sure
exactly which microbial species are part of a healthy
microbiome, nor do they know whether certain bacterial
strains are absolutely vital to mental functioning, or
whether the right balance is what’s key. Furthermore,
research still hasn’t parsed which illnesses might be
affected by the microbiome and, therefore, treatable
using probiotics. “There are beginning to be
suggestions that this type of probiotic treatment is
worth pursuing,” Bienenstock said. “Whether we can
use this to improve people’s lives, well, the door is
just beginning to open on this.”
This article is by Carrie Arnold and was published in
theverge.com
theverge.com
You can read it here:-
http://www.theverge.com/2013/8/21/4595712/
gut-feelings-the-future-of-psychiatry-may-be-inside
-your-stomach
http://www.theverge.com/2013/8/21/4595712/
gut-feelings-the-future-of-psychiatry-may-be-inside
-your-stomach
No comments:
Post a Comment