Acesulfame K, saccharin and the bitter taste receptors they activate
What it found
Saccharin and acesulfame K trigger two specific bitter taste receptors in human cells at levels that cause a bitter aftertaste.
Tests in people matched these cell findings.
What they found
Studies in people
Receptors sit on tongue
The two bitter receptors are found in the taste buds on the human tongue.
Animal and lab studies
Bitter receptors identified
In lab tests on human cells, saccharin and acesulfame K turned on two bitter taste receptors called hTAS2R43 and hTAS2R44. This happened at the same concentrations known to cause a bitter taste.
Sweet blocker had no effect
A substance called lactisole blocked the sweet taste receptor in cells but did not stop the bitter response from hTAS2R43 and hTAS2R44. The authors say these receptors only handle bitterness, not sweetness.
Another bitter compound worked
Very small amounts of aristolochic acid, a purely bitter substance, also activated the same two receptors in the cell tests.
Studies in people and animals
Human taste tests matched
Taste adaptation tests in people supported the cell results. The findings suggest both sweeteners share the same bitter receptors in humans.
What the authors conclude
- They conclude that hTAS2R43 and hTAS2R44 act as the specific bitter taste receptors for saccharin and acesulfame K.
- They note that these receptors do not play any part in the sweet taste of either ingredient.
How it was done
People watching their weight or managing diabetes use saccharin and acesulfame K to cut calories and sugar. A built-in bitter aftertaste limits how much these sweeteners can be used, and scientists did not know what caused it.
Researchers tested saccharin and acesulfame K on lab-grown human kidney cells carrying different taste receptor genes. They also ran taste tests with human volunteers to see if the two sweeteners shared the same bitter pathway.
What it can’t tell you
- We summarised it from the abstract only.
- Lab tests on kidney cells cannot fully show how taste works in a living person eating food.
- The human taste tests looked only at short-term adaptation, so they cannot show long-term effects on food choices.
Who paid
- Authors work at
- German Institute of Human Nutrition Potsdam-Rehbruecke, Germany
The paper
- Title
- Bitter taste receptors for saccharin and acesulfame K
- Type
- Study
- Evidence
- Studies in people · animals · lab
- Summarised from
- Abstract only
- Cite
- Kuhn C, Bufe B, Winnig M, et al (2004). Bitter taste receptors for saccharin and acesulfame K. The Journal of neuroscience. doi:10.1523/JNEUROSCI.1225-04.2004PubMed 15537898DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error