Mindful yoghurt manufacturers often use bacteria that produce more ‘dextrorotatory’ (right-turning) than ‘levorotatory’ (left-turning) lactic acids. Molecules of the two kinds of lactic acid are mirror images of each other. Feeding the human digestive system with levorotatory lactic acid molecules is like giving a left-handed pair of scissors to a right-handed person: they’re hard to handle. That is why it is a good idea to pick yoghurt from the supermarket shelves that says ‘contains mainly dextrorotatory (or right-turning) lactic acid’ on the pot.
