The two most common probiotics for supplementation include L. acidophilus and Bifidobacterium.
L. Acidophilus
Perhaps the most well known probiotic, Lactobacillus acidophilus may grow with or without oxygen, making it extremely versatile. As its name suggests, L. acidophilus produces lactic acid during fermentation of cellulose and other compounds. Lactic acid then lowers intestinal pH, making the intestine undesirable to certain other bacteria.
Bifidobacterium
A highly successful probiotic, bifidobacterium bifidus comprises 25% of all anaerobic organisms in the intestine. It produces two types of acid during fermentation, acetic acid and lactic acid. Together, these acids inhibit growth and kill bacteria more effectively than lactic acid alone.
Bifidobacterium may also play a role in diarrhea prevention.
