L-arabinose occurs naturally in plants, but it's in this formula for a mechanical reason rather than flavor.
It partially blocks sucrase, the enzyme that splits table sugar into absorbable sugars — which can soften the blood-sugar rise that follows a sugary breakfast.
It's the one ingredient here working on blood sugar specifically, separate from the three fermentable fibers or the cellular-renewal ingredient.
In the BrainLive formula: L-Arabinose is one of five named actives — see the full mechanism on how BrainLive works.