Multimodal Chewing Gum Flavour Training to Aid Flavour Perception Recovery - a Pilot Study.

Olfactory training is developed for people who have partly or completely lost their sense of smell (olfactory dysfunction). Participants expose themselves to odours twice daily for usually 12 weeks or longer. It has been proven to effectively help people improve their sense of smell. However, when abnormal flavour perception is reported it may involve not only a dysfunctional sense of smell, but also taste and trigeminal perception (e.g. burning from chilly, cooling from mint, etc.). The stimulation of multiple sensations can theoretically enhance overall flavour perception. Therefore, we propose a pilot study to test the feasibility testing multi-sensation flavour impairment training approach using chewing gum that target sensations of smell, taste and trigeminal. This will be in comparison with an existing olfactory training approach. Individuals (aged 18 to 65) with changed flavour perception (self-perceived, within 3 months to 2 years) will be invited to take part in this study. Participants will be randomly and evenly allocated to 3 groups which are: flavour impairment training using chewing gum (FIT), olfactory training (OT) using smelling strips, and a waiting list control group (CTR) (delaying FIT training for 12 weeks). In the first two groups, a 12-week training will be conducted. The training will be undertaken twice a day (in the morning and evening). All participants will use four flavours in a pre-determined and randomised order. One flavour of chewing gum (FIT group) or smelling strips (OT group) will be used each time. Each training session is expected to last around 3 minutes. In addition to the training, all participants will be asked to pay two visits to the lab, once before and once after completing the 12-week training, or the 12-week wait, to evaluate their flavour (smell, taste and trigeminal) perception capability. Participants will also be asked to conduct flavour perception tests at home before and after training following instructions to evaluate if their flavour perception capability has improved due to the training. The OT group and the CTR group will be offered the FIT treatment after they have undertaken the 12 weeks of their study group allocation.