A rehydration drink needs the sugar to move the salt
A transporter in the gut lining pulls two sodium ions across for every molecule of glucose, which is why the recipe pairs salt with sugar. It describes a gut coping with diarrhoea.
What the study found
Sugar is what carries the salt across the gut wall
A rehydration solution works through a gate that opens only for both at once. SGLT1, a transporter in the lining of the gut, pulls two sodium ions across for every one molecule of glucose, which is why the recipe pairs salt with sugar. It is a gut coping with diarrhoea, not a well person.
The caveat · Textbook physiology, not a trial
This is transport physiology rather than a trial, and the two-to-one ratio is standard textbook mechanism restated by the review, not a new finding of it. The review was written to argue for developing drugs that improve on rehydration therapy, which frames how generously that therapy is described. Its own authors note the treatment reverses dehydration without shortening the illness or reducing stool output.