What are “probiotics”?

Probiotics are normal bacterial residents of the human body. In the intestinal tract, probiotics prevent the growth of pathogenic (harmful) bacteria, and also prevent overgrowth of other probiotic species. Additionally, probiotics break down food products that the body cannot digest, like cellulose, and create chemicals that maintain health of the intestinal lining.

The intestine contains friendly bacteria, called normal flora or probiotics. These bacteria exist with humans in symbiosis, meaning that both humans and probiotics benefit from the relationship.

While some of these bacteria reside in the small intestine, the majority lives and reproduces in the colon of the large intestine. In fact, one gram of the colon contains up to a trillion microorganisms. To understand the full significance of this number, remember that the population of the world is only 6 billion.

With the trillions of colonizing probiotics, there’s not enough space in the intestine for harmful bacteria. Even if a pathogenic bacterium found space, it may not receive enough nutrition. These are the most basic benefits of probiotics – their very presence discourages pathogenic growth through competition.

Probiotics gain their nutrition from materials that humans cannot digest, like cellulose. In the metabolism of cellulose and other compounds, probiotics also release chemicals that discourage growth of pathogenic bacteria. Some of their products also maintain a healthy intestinal lining.

Different species and types of probiotics also compete with each other. Bacteria in the body continuously fight for survival, against all other types of microorganisms. Those bacteria that adapt to the environment and defeat all others will survive.

This continual battleground is necessary for intestinal health. If probiotics do not kill pathogenic organisms, disease could result. If probiotics do not kill each other, one type could take over and intestinal health would be thrown off balance.