Yogurt, a fermented dairy product, contains live cultures, which are microorganisms responsible for transforming milk into yogurt through fermentation. These cultures contribute to its distinct texture and tangy flavor.
Understanding Live Cultures
Live cultures in yogurt are beneficial bacteria that remain active. During yogurt production, these cultures are introduced to milk, consuming lactose and converting it into lactic acid.
This lactic acid causes milk proteins to coagulate, resulting in yogurt’s characteristic thick consistency and tart taste. The presence of these living bacteria distinguishes active culture yogurt from products heat-treated after fermentation.
Key Bacterial Strains in Yogurt
Two bacterial strains, Lactobacillus bulgaricus and Streptococcus thermophilus, are required as starter cultures. These two species work together in a symbiotic relationship; L. bulgaricus produces amino acids from milk proteins that S. thermophilus utilizes, and S. thermophilus creates an environment suitable for L. bulgaricus to thrive.
Beyond these essential starter cultures, many yogurts include additional live strains. Common examples are Lactobacillus acidophilus, Bifidobacterium lactis, and Lactobacillus casei. L. acidophilus contributes to the gut environment. Bifidobacterium lactis is known for its ability to survive acidic conditions. Lactobacillus casei is also acid tolerant.
How Live Cultures Support Your Body
Consuming yogurt with live cultures introduces these microorganisms into the digestive system. These bacteria contribute to the diverse community of microbes residing in the gut, known as the gut microbiome. A balanced gut microbiome is associated with various bodily functions.
The live cultures in yogurt can aid digestive processes. For individuals with lactose intolerance, the bacteria help break down lactose, making yogurt easier to digest than milk. These microorganisms may also support digestive regularity. Furthermore, some research indicates that live cultures can play a role in nutrient absorption.
Choosing Yogurt with Active Cultures
To identify yogurts with living and active cultures, look for specific labeling. In the United States, the National Yogurt Association (NYA) offers a “Live & Active Cultures” (LAC) seal. This seal indicates that the product contained at least 100 million cultures per gram at manufacture.
Not all yogurt products retain live cultures. Some undergo heat treatment after fermentation, which can eliminate the beneficial bacteria. Checking for the LAC seal or ingredient list helps ensure active cultures are present. Heat-treated yogurt may be labeled to indicate the absence of live cultures.