BBC Science Focus - 10.2019

FEATURE

ILLUSTRATION: MAGIC TORCH

YOUR BODY HOSTS A COLONY

OF CREATURES THAT BUILD

THEIR LIVES AROUND YOU.

NOW, SCIENTISTS ARE

BEGINNING TO SEE THAT NOT

ONLY DO THEY INFLUENCE

YOUR HEALTH, THEY CAN EVEN

CHANGE YOUR MIND TOO.

WELCOME TO THE WORLD OF

PSYCHOBIOTICS

EAT

YOURSELF

HAPPY

THE BRAIN CHANGERS

here’s a school of thought

t hat says you a re not

one single organism, but

rather a superorganism

made up of ma ny.

Human cells make up

less than half of what

you call ‘you’ – the rest

are trillions of bacteria,

f u ng i a nd v i r uses i n

your gut, on your skin

a nd t h roug hout you r

tissues. You need them because of the

role they play in digesting your food

and maintaining a healthy immune

system. They need you because they

need somewhere to live.

Now research is providing evidence

that you have an ext ra reason to

treasure the microbes living in the

depths of your bowels: if they’re

happy, you’re happy too. The hitherto

ludicrous-sounding idea that what

happens in your intestines affects

your mood has now got scientific

backing. And it’s become clear that

it’s your gut bacteria that are doing

the communicating with your brain

and affecting your state of mind.

Scientists are providing evidence

for this link, which they refer to as

the ‘microbiome-gut-brain axis’. Not

only that, but they are showing that

altering your gut bacteria (microbiota)

by administering probiotics (live

bacterial supplements) and prebiotics

(d ieta r y f ibre supplement s t hat

encourage bacterial growth), you

can actually improve stress response,

reduce a n xiety a nd mitigate t he

ef fect s of ot her menta l hea lt h

problems.

These findings are giving rise to

a whole new class of medicines:

psychobiotics. The hope is that they

will eventually provide powerful

new treatments for depression and

other mental health conditions,

as well as helping us to deal with

everyday stress and anxiety.

This year a large review of studies

found that probiotics yielded a small

but significant effect in reducing

anxiety and depression. A smaller

st udy, published i n t he jou r na l

Tr a nslat iona l Ps ych iat r y, fou nd

that introducing a Bifidobacterium

probiotic into the guts of healthy

volunteers reduced their feelings of

stress and improved their memory.

“I think the link is pretty strong,”

says Ti m Spector, professor of

genetic epidemiology at King’s

College London. “I’m not meeting 2

T

by SIMON CROMPTON

FEATURE

ILLUSTRATION: MAGIC TORCH

YOUR BODY HOSTS A COLONY

OF CREATURES THAT BUILD

THEIR LIVES AROUND YOU.

NOW, SCIENTISTS ARE

BEGINNING TO SEE THAT NOT

ONLY DO THEY INFLUENCE

YOUR HEALTH, THEY CAN EVEN

CHANGE YOUR MIND TOO.

WELCOME TO THE WORLD OF

PSYCHOBIOTICS

EAT

YOURSELF

HAPPY

THE BRAIN CHA

here’s a school of thought

t hat says you a re not

one single organism, but

rather a superorganism

made up of ma ny.

Human cells make up

less than half of what

you call ‘you’ – the rest

are trillions of bacteria,

f u ng i a nd v i r uses i n

your gut, on your skin

a nd t h roug hout you r

tissues. You need them because of the

role they play in digesting your food

and maintaining a healthy immune

system. They need you because they

need somewhere to live.

Now research is providing evidence

that you have an ext ra reason to

treasure the microbes living in the

depths of your bowels: if they’re

happy, you’re happy too. The hitherto

ludicrous-sounding idea that what

happens in your intestines affects

your mood has now got scientific

backing. And it’s become clear that

it’s your gut bacteria that are doing

the communicating with your brain

and affecting your state of mind.

Scientists are providing evidence

for this link, which they refer to as

the ‘microbiome-gut-brain axis’. Not

only that, but theyareshowingthat

altering your gutbacteria(microbiota)

by administeringprobiotics(live

bacterial supplements)andprebiotics

(d ieta r y f ibre supplement s t hat

encourage bacterialgrowth),you

can actually improvestressresponse,

reduce a n xiety a ndmitigate t he

ef fect s of ot her menta l hea lt h

problems.

These findingsaregivingriseto

a whole new class ofmedicines:

psychobiotics. Thehopeis thatthey

will eventuallyprovidepowerful

new treatmentsfordepressionand

other mental healthconditions,

as well as helpingustodealwith

everyday stressandanxiety.

This year a largereviewof studies

found that probioticsyieldeda small

but significanteffectinreducing

anxiety and depression.Asmaller

st udy, published i n t he jou r na l

Tr a nslat iona l Ps ych iat r y, fou nd

that introducingaBifidobacterium

probiotic into thegutsofhealthy

volunteers reducedtheirfeelingsof

stress and improvedtheirmemory.

“I think the linkis prettystrong,”

says Ti m Spector, professor of

genetic epidemiology at King’s

College London.“I’mnotmeeting 2

T

by SIMON CROMPTON

FEATURE