Related Experiment Video
Updated: Jun 29, 2026

Therapeutic Effectiveness of a Dietary Supplement for Management of Halitosis in Dogs
Published on: July 6, 2015
Urea supplementation is associated with holistic changes in suprathreshold non-volatile flavour perception through
Shuyuan Zhang1, Adrien Le Guennec2, Saeed Shoaie3
1Centre for Host Microbiome Interactions, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK. Shuyuan.2.zhang@kcl.ac.uk.
Abstract:
Urea is a small inorganic compound, readily available in saliva, that can be metabolised by the oral microbiome. We hypothesised that dietary supplementation with urea would increase salivary levels, alter microbial metabolism and, potentially, modify suprathreshold non-volatile flavour perception. A semi-trained panel of 20 participants completed taste evaluations using visual analogue scales for nine tastants, both before and during a 5-day urea supplementation regimen. System-level analysis revealed a significant shift in suprathreshold non-volatile flavour perception during supplementation (PERMANOVA, p = 0.008) even though none of the nine tastants showed significant changes (p > 0.05 or an absolute percentage change greater than 10%) during the intervention. Functional gene completeness analysis, together with 13C NMR, suggested that the oral microbiome primarily utilises carbon dioxide generated from urease-mediated urea metabolism. Overall, urea supplementation was associated with changes in microbiome carbon-related metabolic pathways and induce holistic level changes in suprathreshold non-volatile flavour perception.
Related Concept Videos
Urea Cycle
Overview of Metabolism
Plant Metabolism
Sunlight, the primary source of energy in plants, is first absorbed by the chlorophyll pigments present in their leaves. Plants then use this energy to carry out photosynthesis, where water is oxidized into oxygen and carbon dioxide...
Taste Buds and Receptors
Inorganic Nitrogen Assimilation
Overview of Nitrogen Metabolism
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this nitrogen...
The Physiology of Taste
