Skip to Content
Home > Wellness Resources > Health Library > Probiotics
Probiotics are bacteria that
help keep the natural balance of organisms (microflora) in the
intestines. The normal human digestive tract contains
about 400 types of probiotic bacteria that reduce the growth of harmful
bacteria and promote a healthy digestive system. The largest group of probiotic
bacteria in the intestine is lactic acid bacteria, of which Lactobacillus acidophilus, found in yogurt with live cultures, is the best known.
Yeast is also a probiotic substance. Probiotics are also available as dietary
It has been suggested that probiotics be used to
treat problems in the stomach and intestines. But only certain types of
bacteria or yeast (called strains) have been shown to work in the digestive
tract. It still needs to be proved which probiotics (alone or in combination)
work to treat diseases. At this point, even the strains of probiotics that have
been proved to work for a specific disease are not widely available.
Many people use probiotics to prevent diarrhea, gas, and cramping caused by antibiotics.
Antibiotics kill "good" (beneficial) bacteria along with the bacteria that
cause illness. A decrease in beneficial bacteria may lead to digestive problems. Taking
probiotics may help replace
the lost beneficial bacteria. This can help prevent diarrhea.
decrease in beneficial bacteria may also lead to other infections, such as
vaginal yeast and
urinary tract infections, and symptoms such as
diarrhea from intestinal illnesses.
Probiotics may also
be used to:
Probiotics are being studied for benefits in colon cancer, skin infections, and
irritable bowel syndrome (IBS).
Most probiotics are like what is already in a person's digestive system. Some probiotics have been used for a very long time throughout history, such as in fermented foods and cultured milk products. These don't appear to cause illness. But more study is needed on the safety of probiotics in young children, the elderly, and people who have weak immune systems.
As with any dietary supplement, be aware that probiotic supplements are regulated as foods, not drugs. Tell your doctor about everything you are taking, including the specific bacteria in your probiotic supplement.
Other Works Consulted
National Institutes of Health, National Center for Complementary and Alternative Medicine (2012). Oral Probiotics: An Introduction. Available online: http://nccam.nih.gov/health/probiotics/introduction.htm.
Probiotics (2011). In A DerMarderosian et al., eds., Review of Natural Products. St Louis: Wolters Kluwer Health.
Thomas DW, et al. (2010). American Academy of Pediatrics Clinical Report: Probiotics and prebiotics in pediatrics. Pediatrics, 126(6): 1217–1231.
ByHealthwise StaffPrimary Medical ReviewerAdam Husney, MD - Family MedicineSpecialist Medical ReviewerKathleen Romito, MD - Family Medicine
Current as ofNovember 20, 2015
Current as of:
November 20, 2015
Adam Husney, MD - Family Medicine & Kathleen Romito, MD - Family Medicine
To learn more about Healthwise, visit Healthwise.org.
© 1995-2016 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.