Researchers at UC San Francisco, publishing in Nature on November 4, 2026, report that nutrients arriving in the gut trigger a sustained dopamine signal in the anterior basolateral amygdala, or aBLA.

Senior author Zachary Knight told Science Daily that this slow dopamine system is what drives us to learn to like certain foods over time.

According to The Brighter Side of News, dopamine release with a nutritional formula began about 48 seconds after nutrients reached the stomach and stayed elevated roughly nine minutes after infusion ended.

That delayed, minutes-long signal is very different from the fast dopamine bursts long studied in reward research, and it appears to teach the brain which flavors predict calories.

The surprise is that a calorie-free flavor can be made lovable by directly stimulating the circuit. In the mouse experiments described by both outlets, mice tasted two drinks: licking one delivered glucose into the stomach, the other water.

Control mice's preference for the glucose flavor rose from about 35% of licks to 81% after six days, The Brighter Side of News reports, while silencing dopamine neurons blocked that learning entirely.

Even more striking, pairing light-based stimulation of dopamine fibers in the aBLA with a calorie-free flavor made mice prefer it anyway — stimulation substituted for nutrient feedback.

Knight adds that once the brain links coffee's taste with caffeine's effects, 'that coffee starts to taste a lot better,' a possible explanation for why bitter drinks become morning favorites.

The strongest causal evidence comes from mice, but both outlets describe supporting human imaging.

Science Daily reports that Yale psychologist Dana Small reanalyzed PET data from an earlier milkshake study and found dopamine release concentrated in the left side of the BLA, while an fMRI study of 38 adults led by Marc Tittgemeyer showed increased activity in the same region after glucose consumption.

The Brighter Side of News notes the PET sample was too small for a powered left-right comparison and that fMRI does not directly measure dopamine.

The left-side asymmetry itself surprised Knight, since essential feeding networks are usually expected to be roughly symmetrical; his lab is now investigating why the left hemisphere dominates.

Both outlets stress that treatment applications remain untested. Science Daily reports that Knight did not study GLP-1 medications in this work, and his suggestion that the drugs might work partly by weakening nutrient-driven dopamine signals is a hypothesis, not a demonstrated effect.

Even so, the mapped pathway — from intestinal sensors to amygdala learning — suggests future approaches could target how the brain connects flavors with consequences, potentially changing preferences rather than merely curbing appetite.

'By understanding the steps between nutrient detection in the gut and learning in the brain, it might be possible to fine-tune them to subtly change our preferences for different foods,' Knight told Science Daily.

The Brighter Side of News adds caveats: caffeine, aroma and social experience are separate from the glucose-driven learning studied here, and coffee's particular appeal is not fully resolved.