Specific ingredients for helping ailments has never been tried as far as I'm aware. If you can find out which fruits help which ailments, you could be helping people as well as serving delicious drinks. I have found out recently that honey mixed with powdered cinnamon is a cure for many complaints. It would go well in a banana smoothie.
citrus fruits not good for gout sufferers but strawberries are.
blackcurrants good for skin and glossy hair as they are full of wit c
elderflower very refreshing on hot days.
I have a couple of books one called super juice and the other called juicing for health which have combinations for smoothies and shakes that are for health and healing, although the first one is the only one of the two to actually say what they are supposed to help. Might be worth trying to get a copy from your local library.
A smoothie is an amalgamation of various foodstuffs processed into a drinkable product. These individual foodstuffs are varied in colour and shape. On entering an establishment purveying such items I would expect the decorations to reflect theme of the product. Bright and gaudy and abstract decor is a must.
But then I'm only an 'early retired' social worker. But it'll get the clientele talking...................!!!!!!!!!!!!!!!!!!!