News Pix the Planet IU!!Wllletter
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Sugar or sweetener? Your gut
can tell the difference
CAN you taste the difference
between sugar and a zero-calorie
sweetenerl It seems specialised
cells in your gut probably can
wlthinmOllseconds.
Resean:hinthe195osi:evealed
that food doesn't need to pass
through the mouth to stimulate
the brain-mice respond in this
waywbenfoodsareputdiredly
into their stomachs, too.
Two years ago, Diego
BohmquezatDuke Uniwisityin
North camlinaandhiscolleagues
!dentffteda new type of cell that
gives the gut ita ownabfiltyto
sense nutrients. These neumpod
cells were spotted in the intestines
of mice, and rapidly sent sigoals
via thevagus nerve, which links
the gut to the brain, related to
the presence of sugary snacks.
TD find out whether these cells
can tell the d!f'ference between
sugar andzero..calcnie sweeteners,
the researchers put a range of
sugars and sweeteners into the
gutsofmire.Atthesametime,
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the team used a device to measure
vagus nerve adivity. All of the
sugars triggered the neuropod
cells to send a signal tothevagus
nerve-exceptforfructose.
The fact that fructose, anatwal
sugar found in fruit, doesn'tseem
to trigger a rapid signal to the
brain may explain why fruit
doesn't give our brains the same
mvud as chocolate, says Elisa Hill
at RMITUnivenity in.Australia.
"It would be great to know if these
systems cm be trained to favour
fruit over chocolate," she says.
In another set of experiments,Bohorquez and bis team studied
oiganoids, small lumps ofliving
tissue grown from cells taken from
the intestines of mice or humans.
The team found that only sugars
that contamed calories triggered
release of a compoundcalled
glutamate as a signal to the vagus
nerve. 7.ero-c:alorie sweetenen
delivered an entirely separate
sigDa1 tothevagusnerve, via a"It would be great to know
If sweet-sensing gut cetls
can be trained to favour
fruit over chocolate"compound calledA1P (bioRxiv,
doiorg/dP43).
The findings suggest the gut
senses the sweet taste and calorie
content of substances separately,
and sends both signals to the brain
within mllliseconds. This sense
might have evolved to enable
anJmals to find energy-rich foods,
says Jonathan Swann at lmperlal
College London. "Determining
what's energy-dense and what's
energy-sca.rt"e would be very
important in seeking out foods."
It is likely that similar cells are
doing the same thing in people's
guts, says Hill. If so, tinkering
withthewaythecellswortmay
inluencethewayourbrams
respond to sweet foods. In the
futwe, the cells could be targeted
in treatments to modify eating
behaviours and for some people
with obesity. she says.
Neuropod cells may also be
=i a way for gut bacteria to rapidly
I commun!catewiththe bnin, says
~ Swann. Disruptions to the gut
9 microbiomehavebeenlinted to
i a range of neurological disord.en,
i including Parlcinaon'1 disease and
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