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Author:

Betty Kovacs, MS, RD

Betty Kovacs, MS, RD

Betty is a Registered Dietitian who earned her B.S. degree in Food and Nutrition from Marymount College of Fordham University and her M.S. degree in Clinical Nutrition from New York University. She is the Co-Director and Director of nutrition for the New York Obesity Research Center Weight Loss Program.

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Medical Editor:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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In this Article

• What are probiotics?
• What is the gut?
• What are the health benefits of probiotics?
• What are the different types of probiotics?
• What foods contain probiotics?
• What are the side effects and risks of probiotics?
• How should people take probiotics?
• Where can I get more information on probiotics?
• Probiotics Index

What are the different types of probiotics?

Probiotic products contain bacteria and/or yeasts that assist in restoring the balance in our gut. Up until the 1960s, the gut microflora that they were able to identify were clostridia, lactobacilli, enterococci, and Escherichia coli. Since then, innovative techniques have discovered many more bacteria.

There are several different kinds of probiotics, and their health benefits are determined by the job that they do in your gut. Probiotics must be identified by their genus, species, and strain level. Here is a list of probiotics and their possible health benefits.

1. Lactobacillus

There are more than 50 species of lactobacilli. They are naturally found in the digestive, urinary, and genital systems. Foods that are fermented, like yogurt, and dietary supplements also contain these bacteria. Lactobacillus has been used for treating and preventing a wide variety of diseases and conditions.

Some of the lactobacilli found in foods and supplements are Lactobacillus acidophilus, L. acidophilus DDS-1, Lactobacillus blugaricus, Lactobacillus rhamnosus GG, Lactobacillus plantarium, Lactobacillus reuteri, Lactobacillus salivarius, Lactobacillus casei, Lactobacillus johnsonii, and Lactobacillus gasseri.

More research is needed regarding probiotics and their potential health benefits before any definitive claims can be made about their effects. However, studies have shown some benefits linked to Lactobacillus and treating and/or preventing yeast infections, urinary tract infection, irritable bowel syndrome, antibiotic-related diarrhea, traveler's diarrhea, diarrhea resulting from Clostridium difficile, treating lactose intolerance, skin disorders (fever blisters, eczema, acne, and canker sores), and prevention of respiratory infections. More specifically, results from some of the studies are as follows:

• Lactobacillus GG was given to children 5 to 14 years of age with irritable bowel syndrome over eight weeks' time. They were given 3 billion cells twice per day. This reduced the frequency and severity of abdominal pain.
• Lactobacillus GG was given to children taking antibiotics and there was a decrease in reported diarrhea.
• Lactobacillus casei, Lactobacillus bulgarius, and Streptococcus thermophilus given twice daily during antibiotic treatment and for a week later decreased the risk of diarrhea in hospitalized adults.
• Lactobacillus GG-containing milk was given to children 1 to 6 years of age who attended day care. They got fewer or less severe lung infections than those who did not drink it.
• Lactobacillus gasseri and Lactobacillus rhamnosus vaginal capsules lengthened the time in between bacterial vaginosis infections.
• Lactobacillus GG reduced the risk of traveler's diarrhea by 47% in a study with 245 people who traveled to 14 worldwide geographic regions.

2. Bifidobacteria

There are approximately 30 species of bifidobacteria. The make up approximately 90% of the healthy bacteria in the colon. They appear in the intestinal tract within days of birth, especially in breastfed infants.

Some of the bifidobacteria used as probiotics are Bifodbacterium bifidum, Bifodbacterium lactis, Bifodbacterium longum, Bifodbacterium breve, Bifodbacterium infantis, Bifodbacterium thermophilum, and Bifodbacterium pseudolongum.

As with all probiotics, more research is needed to prove a definitive benefit, but studies have shown that bifidobacteria can help with IBS, dental cavities, improved blood lipids, and glucose tolerance.

• Bifidobacterium infantis 35624 was given to 362 patients with irritable bowel syndrome in a four-week study. They showed improvement in the symptoms of abdominal pain, bloating, bowel dysfunction, incomplete evacuation, straining, and the passage of gas.
• Salivary levels of bifidobacteria are associated with dental cavities in adults and children.
• Bifidobacterium lactis Bb12 is reported to have beneficial effects on metabolism, including lowered serum LDL-cholesterol in people with type 2 diabetes, increased HDL in adult women, and improved glucose tolerance during pregnancy.

3. Saccharomyces boulardii

This is also known as S. boulardii and is the only yeast probiotic. Some studies have shown that it is effective in preventing and treating diarrhea associated with the use of antibiotics and traveler's diarrhea. It has also been reported to prevent the reoccurrence of Clostridium difficile, to treat acne, and to reduce side effects of treatment for Helicobacter pylori.

4. Streptococcus thermophilus

This produces large quantities of the enzyme lactase, making it effective, according to some reports, in the prevention of lactose intolerance.

5. Enterococcus faecium

This is normally found in the intestinal tract of humans and animals.

a. E. faecium SF68
b. E . faecium M-74

6. Leuconostoc

This has been used extensively in food processing throughout human history, and ingestion of foods containing live bacteria, dead bacteria, and metabolites of these microorganisms has taken place for a long time.