Immune system regulates bitter taste: study
22 Apr 2015
"Bitter" taste is regulated by the immune system according to new research.
According to senior author Hong Wang, molecular biologist at Monell Chemical Senses Center, Philadelphia, said, specifically, the tumour necrosis factor (TNF) protein might make sick people more sensitive to bitterness, so that foods tasted more bitter and less appetising.
The finding could help explain the taste system abnormalities and lowered food intake associated with infections, autoimmune disorders and chronic inflammatory diseases.
In addition to its role in mediating inflammation, TNF had been implicated in the progression of varied diseases ranging from Alzheimer's disease to cancer.
The researchers first compared taste responses of normal mice to mice that were engineered to lack the gene for TNF (TNF knockout mice).
The TNF knockout mice were revealed to be less sensitive to bitter-tasting compounds in two different behavioural tests. This showed that the knockout mice required higher levels of bitterness than normal mice in order to show a response.
No difference in response was observed to sweet, salty, umami and sour tastes in the two sets of mice.
Reduced food intake and associated malnutrition was a significant concern that affected the long-term prognosis of many people, who were very ill.
The new research established a functional link between the immune and taste systems.
The authors further noted that an interesting question to consider was whether changing the levels of TNF, perhaps by using inhibitors, could modulate bitter taste sensations.
The journal Brain, Behaviour, and Immunity has published the findings.
