How the gut senses sugar and drives preference
What it found
In animals, sugar in the gut is detected by specific cells that send fast signals to the brain, shaping the desire to eat sugar independently of sweet taste.
The work is based on studies in mice and rats.
What they found
Animal and lab studies
Gut sensors for sugar
In mice, certain duodenal cells called neuropod cells detect glucose using a transporter called SGLT1 and release glutamate onto vagal nerve cells.
Sweet taste not required
Mice without working sweet taste receptors can still learn to prefer sugar over artificial sweetener, showing that sugar preference does not depend only on taste.
Fast gut-to-brain signal
Glucose applied to the gut triggers vagal firing within milliseconds, and blocking glutamate receptors in the gut stops mice from telling sugar from sweetener.
Brain reward circuits
In mice, sugar in the gut activates dopamine pathways in the brain that assign value to food, separate from pathways activated by sweet taste in the mouth.
Hunger neurons suppressed
In mice, glucose infused into the gut quickly reduces the activity of AgRP neurons, which are involved in hunger, and this depends on SGLT1.
Artificial sweeteners
Artificial sweeteners can activate sweet taste receptors but do not trigger the SGLT1-dependent gut pathway that sugar does.
What the authors conclude
“Artificial sweeteners cannot improve dietary choices alone because while artificial sweeteners can trick oral taste-receptor signalling, they do not trigger the intestinal SGLT1-dependent glutamatergic signalling pathway.”
Also in their conclusions
- They propose a model where sugar is sensed along the gut and this information is relayed to brain circuits that control consumption and learning.
- They say that artificial sweeteners cannot improve dietary choices alone because they do not trigger the intestinal SGLT1-dependent pathway.
- They suggest that understanding gut sensing could help promote healthy eating habits.
How it was done
The authors wanted to understand how animals detect and choose sugar, because efforts to curb intake using artificial sweeteners that only target taste have failed.
They reviewed decades of animal studies, including experiments where mice and rats were given sugars or sweeteners directly into the gut, and brain circuits were measured or manipulated.
What it can’t tell you
- These studies are mostly in mice and rats, so they cannot show how sugar sensing works in people.
- The review does not measure long-term health effects of sugar or sweeteners in people.
Who paid
- Funding
- Funded by NIMH NIH HHS; NIDDK NIH HHS; NCCIH NIH HHS; NIGMS NIH HHS (from the PubMed record).
- Authors work at
- Duke University, USA
The paper
- Title
- The neural basis of sugar preference
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Cite
- Liu WW, Bohórquez DV (2022). The neural basis of sugar preference. Nature reviews. Neuroscience. doi:10.1038/s41583-022-00613-5Free full textPubMed 35879409DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error