The human body hosts trillions of microorganisms that support various bodily functions, forming a complex ecosystem known as the microbiome. Probiotics are live microorganisms, primarily bacteria and yeasts, that offer health benefits when consumed in appropriate amounts. This article explores what “alive” signifies for probiotics and why their viability is central to their effectiveness.
What Makes Probiotics Alive
The term “live cultures” indicates that probiotics contain viable, active microorganisms capable of multiplying and forming colonies. Their effectiveness relies on these organisms reaching the gut alive to exert their beneficial effects.
A key measurement for probiotic products is Colony-Forming Units (CFUs), which quantifies the number of living, active microorganisms in each serving. Probiotic products typically specify their CFU count on the label, often ranging from 1 billion to over 100 billion.
While a high CFU count is important, these organisms must also remain alive and active until consumption. Manufacturers use methods like freeze-drying and protective packaging to ensure probiotics survive storage and transit. Proper storage, often involving refrigeration for certain strains, helps maintain their viability.
How Probiotics Support Health
Live probiotics contribute to a balanced gut microbiome by increasing the population of beneficial microorganisms. They actively compete with potentially harmful bacteria for space and nutrients within the gut. This competition helps control the growth of less beneficial microbes, supporting overall gut health.
Probiotics also produce beneficial compounds, such as short-chain fatty acids (SCFAs), including acetic, propionic, and butyric acids. These SCFAs serve as an energy source for colon cells and maintain gut integrity. Certain strains, like Lactobacillus and Bifidobacterium, are known SCFA producers. These compounds also have broader effects, contributing to immune regulation and inhibiting inflammation.
Probiotics also support immune function, with a significant portion of the immune system residing in the gut. They interact with gut cells, enhancing the intestinal barrier function and influencing immune signaling pathways. This can lead to increased production of protective substances, such as secretory IgA, and the modulation of immune cell activities. They may also help train the immune system to recognize and eliminate harmful microbes.
Beyond these roles, probiotics can aid in nutrient absorption and contribute to digestive regularity. A healthy gut microbiome helps break down and absorb certain nutrients and medications. By helping to restore microbial balance, live probiotics can improve overall gut function, which may alleviate discomfort and support consistent bowel movements.
Finding and Using Live Probiotics
Live probiotics can be found in a variety of sources, including both fermented foods and dietary supplements. Fermented foods like yogurt, kefir, sauerkraut, kimchi, and tempeh naturally contain live microorganisms. These foods provide a nourishing environment for beneficial bacteria to thrive.
When selecting probiotic supplements, several factors are important to consider to ensure you are getting viable organisms. It is advisable to look for products that specify the genus, species, and strain of the probiotics. Common genera include Lactobacillus and Bifidobacterium, which encompass numerous strains with different effects. The CFU count is also important, with many effective products containing 1 billion to 10 billion CFUs per dose for general health.
Proper storage is crucial for maintaining the viability of probiotics. Some probiotic supplements require refrigeration, while others are shelf-stable due to freeze-drying or other protective technologies. Always check the product label for specific storage instructions, as heat and moisture can reduce the number of viable CFUs over time. Consuming probiotics with food may help buffer stomach acid and improve their survival as they pass through the digestive system.
Considerations for Live Probiotic Use
While generally safe for most healthy individuals, live probiotics can sometimes cause mild, temporary side effects like gas, bloating, or mild diarrhea. These symptoms typically subside as the body adjusts.
However, certain populations should exercise caution and consult a healthcare professional before use. This includes individuals with compromised immune systems, those who are critically ill, premature infants, or those undergoing cancer treatments, recent surgery, or with severe underlying health conditions.
The U.S. Food and Drug Administration does not regulate probiotic supplements in the same way as medications.