Table 6 Metabolic fates of low-calorie sweeteners approved in the European Union (adapted from [107])

Saccharin (81-07-2)

Not metabolised, excreted unchanged.

Urine

[109, 110]

Acesulfame-K (55589-62-3)

Not metabolised, excreted unchanged.

Urine

[108]

Aspartame (22839-47-0)

Hydrolysed to aspartic acid, phenylalanine and methanol.

N/A

[121, 122]

Cyclamate (139-05-9)

80% of the population do not metabolise cyclamate. In 20%, it undergoes partial hydrolysis in the gut to cyclohexylamine. Extent of hydrolysis varies between and within individuals.

Faeces, urine

[113]

Thaumatin (53850-34-3)

Undergoes normal protein digestion.

N/A

[123]

NHDC (20702-77-6)

Metabolised by gut microflora to similar metabolites to naturally occurring flavonoids.

Urine

[124]

Salt of aspartame-acesulfame (106372-55-8)

Dissociates to individual sweeteners in digestive fluids and undergoes same metabolic fates.

See information for acesulfame-K and aspartame

[134]

Sucralose (56038-13-2)

Not metabolised, excreted mainly unchanged but 2% of absorbed portion excreted as conjugates.

Faeces, urine

[114, 115]

Steviol glycosides^†

Bacterial hydrolysis in the gut to steviol which is then absorbed and excreted as steviol glucuronide.

Urine

[117,118,119]

Advantam (714229-20-6)

Converted to advantame acid and mainly excreted as such with 2 minor metabolites.

Faeces, urine

[120]