Sina Health Centre


What are probiotics?

Probiotics are live organisms that naturally live in the intestine. These are good organisms that help control unfriendly bacteria and viruses that cause diseases such as diarrhea. Probiotics are primarily thought to act by blocking colonization of the gut by pathogenic bacteria.

Probiotics for Diarrhea

You may have heard of using probiotics to help treat diarrhea.  Lactobacillus species have shown to reduce the duration of diarrhea, particularly in rotaviral infections.

For antibiotic-associated diarrhea, Lactobacillus rhamnosus GG, S. boulardii, and probiotic mixtures appear to be effective prophylactic agents if taken along with antibiotics. They have shown to reduce the incidence of diarrhea by about 60%-65%.

  • Results of studies looking at probiotics for traveler’s diarrhea have been mixed. Studies using Lactobacillus species have shown very modest or no effect. Combination treatment with L. acidophilus, L. bulgaricus, B. bifidum, and S. thermophilus may be better for reducing the frequency of diarrhea, but there have been no head-to-head comparisons with single agents.


  • infantismay benefit abdominal discomfort, bloating, and difficult bowel movements in irritable bowel syndrome.


  • Activia yogurt containing  lactis is marketed to regulate the digestive system. This product has been shown to speed gut transit time. However, its efficacy for constipation, irritable bowel, or any gastrointestinal disease or symptom has not been studied. People who like yogurt can try Activia to see if it helps with bloating or difficulty passing stool. Suggest one to three servings daily for at least ten to 14 days. Effects on gut transit time last at least two weeks after consumption.


  • Yakult, a beverage containing Lactobacillus casei Shirota, might benefit chronic constipation. It improved severity of constipation, softened stool, and increased stool frequency in one study. Benefits were noted after two weeks.


  • The probiotic combination Howaru Protect ( acidophilus NCFMand B. lactis Bi-07) is possibly effective for preventing cold and flu symptoms during the winter months in children ages three to five years.


Are they effective?

Below are products commonly found in pharmacies and a comparison of their usage and efficacy.

Comparison of Common Probiotic Products

Product Contents Promoted Use Labeled Dose or Dose Used in Studies Efficacy
Activia yogurt Bifidobacterium lactis DN-173 010: At least 100 million live & active bacteria per gram Regulates digestive system Consume daily for two weeks as part of balanced diet and healthy lifestyle Speeds gut transit time, but has not been studied for treatment or prevention of constipation
Bio-K+ Lactobacillus acidophilus CL 1285, L. casei LBC8R12.5 billion (regular strength), 25 billion (strong), or 50 billion (extra strength) live bacteria per capsule50 billion active bacteria/98 g bottle fermented beverage Promotes and maintains a healthy and balanced digestive system For digestive health:
one to two capsules daily, or one bottle (beverage) daily for a month, then ½ to one bottle daily (children over age of one: ½ to one bottle daily)To prevent antibiotic-associated diarrhea: one bottle or two extra-strength capsules daily within 24 to 48 hours of starting antibiotic. Continue until five days after stopping antibiotic. Take two hours after antibiotics.
Possibly Effective for reducing incidence and duration of antibiotic-associated diarrhea (including C. diff colitis) in inpatients.
DanActive Lactobacillus bulgaricus
Streptococcus thermophilus
Lactobacillus casei 
(strain used in product is trademarked L. casei Immunitas [Defensis in Canada]) Over 10 billion live and active L. casei per bottle
Strengthen the body’s defenses Strengthen defenses:
at least one bottle dailyPrevention of antibiotic-associated diarrhea (hospitalized adults):
one bottle twice daily during treatment and for one week afterward
Possibly Effective for preventing or reducing severity of acute diarrhea in infants and young children, and prevention of antibiotic-associated diarrhea (including Clostridium difficile diarrhea) in hospitalized adults
Florastor (Do not refrigerate) Saccharomyces boulardii lyo 250 mg per capsule or packet Protect against digestive imbalance due to antibiotics, travel, stress diet, or other digestive issues Digestive health (two months of age and older):
one capsule or packet twice dailyPrevention ofantibiotic-associated diarrhea:
two capsules twice daily beginning within three days of antibiotics, and continuing for three days after discontinuationPrevention of traveler’s diarrhea:
one or two capsules daily beginning five days before travel and continued for duration of tripTo prevent C. difficile recurrence:
two capsules twice daily for four weeks (with appropriate antibiotics)HIV-associated diarrhea:
1 gram three times daily, tapered to 1 gram daily to control diarrheaTube-feed diarrhea:
500 mg four times daily; has been used for up to 28 days
Possibly Effective for prevention of antibiotic-associated diarrhea, traveler’s diarrhea, and diarrhea in tube-fed patients prevention of recurrence of C. difficile colitis (adjunctive therapy); treatment of HIV-associated diarrhea; and treatment of diarrhea in infants
Jamieson Probiotic Sticks
(Jamieson Natural Sources)
Lactobacillus helveticus and Bifidobacterium longum1 billion colony-forming units per powder stick Balances gut flora to maintain health, decreases stress-related digestive symptoms One powder stick daily with a meal Possibly Effective for stress-related digestive symptoms (e.g., pain, nausea, vomiting, etc)
VSL#3 (Requires refrigeration, but can be kept at room temperature for up to a week with no potency loss) Lactobacillus acidophilus, L. plantarumL. paracaseiL. bulgaricus, Bifidobacterium breveB. infantisB. longum, and Streptococcus thermophilus 450 billion live bacteria per packet, and 225 billion live bacteria per two capsulesNOTE: Dosing for children based on age, weight, and number of bowel movements daily. See product information. Provide probiotics to protect the gastrointestinal tract and modulate intestinal inflammation to aid in the management of ulcerative colitis, irritable bowel syndrome, and ileal pouch Bloating and gas associated with diarrhea-predominant irritable bowel syndrome:
½ to one packet or two to four capsules dailyPouchitis, remission (maintenance):
two to four packets or six to 18 capsules dailyUlcerative colitis, remission (maintenance):
one to two packets or four to eight capsules dailyUlcerative colitis, active (adjunct):
four to eight packets or 16 to 32 capsules daily
Possibly Effective for maintenance of remission in pouchitis; bloating associated with diarrhea-predominant irritable bowel syndrome; achievement and maintenance of remission in ulcerative colitis
Yogurt Content varies. Choose a product with the National Yogurt Association’s seal to assure the product contains 100 million live and active bacteria per gram (e.g., DannonYoplait) N/A Prevention of antibiotic-associated diarrhea: Four to eight ounces twice daily Yogurt is Possibly Effective for prevention of antibiotic-associated diarrhea or recurrent vaginal candidiasis
UltraFlora IB 60 billion live organisms L. acidophilus NCFM and B. lactis Bi-07. Helps relieve abdominal discomfort, bloating, cramping, bowel irritation, and occasional urgent bowel movements. Take one capsule one to two times daily or as directed by your healthcare practitioner.
UltraFlora Balance  L. acidophilus NCFM and B. lactis Bi-07  (15 billion live organisms) Daily support for GI and immune health Take one capsule one to two times daily or as directed by your healthcare practitioner.
UltraFlora Acute Care S. boulardii (providing 5.5 billion live organisms), B. Lactis HN019 (combines  4 billion live organisms), and L. Rhamnosus HN001 (combines  4 billion live organisms) Targeted Relief for Acute Bowel Distress Take one capsule one to two times daily or as directed by your healthcare practitioner.



Generally, probiotics are very safe even in those with compromised immune function. Infections caused by lactobacilli, bifidobacteria, and Saccharomyces are extremely rare in humans. In some people, probiotics can cause stomach and intestinal upset, including gas and bloating which usually improve with time. The calcium in yogurt can also decrease the effectiveness of some antibiotics.



  1. Canadian Pharmacists Letter. [Online, Dec. 08, 2014] Available from:
  2. Natural Medicines Comprehensive Database [Online, Dec. 08, 2014]
  3. Marteau P, Cuillerier E, Meance S, et al. Bifidobacterium animalis strain DN-173 010 shortens the colonic transit time in healthy women. A double-blind randomized controlled study. Aliment Pharmacol Ther2002;16:587-93.
  4. Meance S, Cayuela C, Turchet P, et al. A fermented milk with Bifidobacterium animalis strain DN-173 010 shortened oro-fecal gut transit time in elderly. Microb Ecol Health Dis 2001;13:217-22.
  5. Meance S, Cayuela C, Raimondi A, et al. Recent advance in the use of functional foods: effect of the commercial fermented milk with Bifidobacterium animalis strain DN-173 010 and yogurt strains on gut transit time in the elderly. Microb Ecol Health Dis 2003;15:15-22.
  6. Dannon. Get answers to frequently asked questions about Activia
  7. Danone. Activia FAQ.
  8. Bio-K+ International Inc. Probiotics FAQ.