Yogurt is easier to digest than milk because its live bacteria help break down lactose.

Lactose intolerance affects approximately 65 percent of the human population after infancy, according to data from the National Institutes of Health (NIH). The condition stems from a deficiency in the enzyme lactase, which is produced in the small intestine. Without enough lactase, undigested lactose moves into the colon, where it interacts with normal bacteria to cause bloating and gas.Yogurt production relies on specific starter cultures, typically Lactobacillus bulgaricus and Streptococcus thermophilus. During the fermentation process, these bacteria produce their own lactase enzyme to metabolize the milk sugar into lactic acid. This biological activity reduces the total lactose concentration of the product by about 20 to 30 percent before it is even consumed.A landmark study published in the New England Journal of Medicine found that individuals with lactase deficiency absorbed lactose from yogurt much better than from milk. The researchers discovered that the bacterial lactase survives the acidic environment of the stomach. Once it reaches the small intestine, the enzyme is released and assists the body in digesting the remaining lactose.The European Food Safety Authority (EFSA) officially recognized this health claim in 2010, confirming that live yogurt cultures improve lactose digestion. For maximum benefit, the yogurt must contain at least 100 million colony-forming units (CFU) of live bacteria per gram. This internal digestion aid is why many people who experience distress from a glass of milk can enjoy yogurt without symptoms.