Soy yogurt, also referred to as Soya yogurt, Soygurt or Yofu (a portmanteau of yogurt and tofu), is yogurt prepared with soy milk.

Soy yogurt is made using soy milk, adding yogurt bacteria, sometimes adding sweeteners such as fructose, glucose, or sugar.

It is suitable for vegans, ovo-vegetarians, for people with PKU (Phenylketonuria) or other dangerous diseases, and for those with lactose intolerance or milk allergy, as the bacteria for shop-bought soy yogurt are usually not grown on a dairy base. Due to certain recurring doubts and controversies about the bacterial cultures used, most soy yogurt manufacturers nowadays include certified labels, usually by the Vegan Society or similar vegan organisations, clearly visible on the outer packaging.

More Info: en.wikipedia.org