Probiotics – the benefits
Probiotics are live microorganisms administered to boost the immune system and improve microbial balance, by replenishing normal intestinal flora.
Probiotics are regulated as dietary supplements and are also present in certain foods. Typically, a probiotic should contain several billion microorganisms to increase the chance of adequate gut colonization.
The most commonly used probiotics are the yeast strain Saccharomyces boulardii and the lactic acid bacteria, particularly Lactobacillus and Bifidobacterium species.
Mechanism of Action
Probiotics exert their beneficial effects through various mechanisms:
• Lowering intestinal pH;
• Decreasing colonisation and invasion by pathogenic organisms; and
• Modifying the host immune response.
Clinical Evidence
There is increasing clinical evidence to support the use of probiotics in the following conditions:
• Antibiotic-associated diarrhoea;
• Traveller’s diarrhoea;
• Vaginal yeast infections;
• Urinary tract infections;
• Irritable bowel syndrome;
• Inflammatory bowel disease;
• Helicobacter pylori infections; and
• Atopic eczema in children.
The strongest evidence for the clinical efficacy of probiotics has been in the treatment of acute diarrhea, most commonly due to rotavirus, and pouchitis.1
Safety
Probiotics are generally regarded as safe and well tolerated. They should however, be used cautiously in patients who are critically ill or severely immunocompromised.
Storage and Dosing
Bacteria-derived probiotics should be separated from antibiotics by at least two hours. To assist with compliance, some newer supplemental probiotics do not require refrigeration.
GPs can:
• Educate patients about the benefits of probiotics;
• Consider probiotics for patients who travel overseas; and
• Encourage patients to seek further clarification about optimal probiotic dosing from their pharmacist.
Useful URLs
National Centre for Complementary and Alternate Medicine (NCCAM) www.nccam.nih.gov
Natural Medicines Comprehensive Database www.naturaldatabase.therapeuticresearch.com
MedlinePlus: Drugs, Supplements and Herbal information www.nlm.nih.gov/medlineplus