Reflex Plus Cat Food Xylo-oligosaccharides (XOS) are super prebiotics obtained by hydrolysis of corn cobs. XOS helps to reduce problems such as unwanted fat and glycemia in cats with approximately zero calorie value. XOS enters the large intestine without modification and is primarily used by the digestive bacteria Bifidobacteria and Lactobacilli. This reduces negative fermentations that cause energy loss, such as bloating and other digestive ailments.