Like yogurt, kefir is a food made from fermented milk. Rich in probiotics, kefir is said to enhance health by boosting immunity, stimulating the digestive system, and protecting against a number of common health problems. For example, many proponents suggest that kefir can shield heart health by keeping your cholesterol in check. While there's very little evidence that kefir can reduce your cholesterol levels, preliminary research indicates that soy-milk-based kefir may offer some cholesterol-fighting benefits. If you're looking for an all-natural way to lower your cholesterol, try sipping green tea, eating moderate amounts of soy, and using cinnamon to flavor your food. In addition, some studies show that consuming oats, flaxseed, and hibiscus tea on a regular basis may help prevent high cholesterol.