Probiotics - the Research

Probiotics are live bacteria and yeast, also known as “friendly bacteria,” that help maintain the natural balance in the gut. They are vital for a healthy immune system, protect against infections, and help in both digestion and absorption of food. The normal gut has hundreds of types of friendly bacteria. The most well- known probiotics used in medicine are Lactobacillus acidophilus, occurring naturally in yogurt, and Bifidobacterium, commonly found in the gut of breast-fed infants and thought to help confer natural immunity from disease. There are certain strains of yeast, such as Saccharomyces boulardii, that also function as probiotics.

Scientific Evidence

The best evidence for probiotics is in the treatment of diarrhea, irritable bowel syndrome, and the intestinal infection caused by Clostridium difficile, to prevent and treat infections of the urinary tract or female genital tract, to reduce recurrence of bladder cancer, and to prevent and manage dermatitis/eczema in children.

Which Strains to Take
When considering the use of probiotics, there is always a question of which strain to use. Because these bacteria are normally killed in the stomach, it is important to identify those strains that have been shown to actually colonize the GI tract. Different strains are effective for different health issues. Studies performed in inflammatory bowel disease suggest that high doses of combinations of different probiotic strains are more effective in decreasing inflammation and maintaining patients in remission than a single probiotic strain. There are many strains and a variety of research.

The following attachments are a draft attempt to summarize this information:
Probiotic indications species studied - Probiotic indications with species studied and level of evidence March 2013

Probiotic products with studied indications - Some commercial products with the species contained and their studied indications March 2013

Probiotic species for indication.xlsx- Excel version of the above with some of the references as well as species studied and found not to be effective for particular indications

Prebiotics (to distinguish from probiotics) are nondigestible carbohydrates that selectively stimulate the growth of the beneficial bacteria already present in the gut. Prebiotics can be taken in supplement form as fructo-oligosaccharides (FOS) and/or inulin and may be taken with probiotics. Food sources include oat bran, onions, asparagus, chicory, and banana.