Irritable Bowel SyndromeA daily drink containing probiotics significantly reduced IBS symptoms in one study.In several double-blind trials, probiotic products have been found to relieve symptoms of IBS. Preparations that have been found to be effective include 1) a combination of Lactobacillus rhamnosus GG, L. rhamnosus Lc705, Propionibacterium freudenreichii ssp. shermanii JS and Bifidobacterium animalis ssp. lactis Bb12;1 2) Lactobacillus GG;2 3) a combination of Lactobacillus acidophilus NCFM and Bifidobacterium lactis Bi-07;3 and 4) a product known as VSL#34
ConstipationResearch has shown that the probiotic strain Lactobacillus casei Shirota may help relieve chronic constipation after two weeks of supplementation.In one double-blind study, 70 people (average age, 44 years) with chronic constipation were randomly assigned to receive 65 ml/day of a probiotic beverage or placebo for four weeks.5 The probiotic beverage provided daily at least 6.5 billion colony-forming units of Lactobacillus casei Shirota. The treatment group began showing statistically significant improvements at the end of the second week. At the end of the treatment period, the proportion of patients having moderate or severe constipation was 34% in the active-treatment group and 83% in the placebo group. Another double-blind trial found that a probiotic supplement taken for 4 weeks significantly increased bowel movement frequency in adults with constipation. The product used in that study provided 200 million colony-forming units of Lactobacillus reuteri DSM 17938 per day, and was taken twice a day after meals.6
Tooth DecaySupplementing with probiotics may inhibit cavity-causing bacteria.
In a double-blind study of children aged 1 to 6 years, supplementation with Lactobacillus GG five days a week in milk for seven months reduced the incidence of cavities by 49%, compared with unsupplemented milk.7 The amount of Lactobacillus added to the milk was 5 to 10 x 105 CFU per ml.In another study, supplementing with Lactobacillus reuteri strain ATCC 55730 (derived from breast milk) significantly decreased the number of children who had dental cavities at 9 years of age. The probiotic was given in the amount of 108 colony-forming units per day to the mother during the last 4 weeks of pregnancy, and then to the infant in the same daily amount during the first year of life.8
ColicResearch suggests probiotics may benefit babies with colic who are breast-fed or fed milk-based formula.
In a double-blind study of infants, supplementation of a standard milk-based formula with probiotic organisms (Bifidobacterium lactis and Streptococcus thermophilus) significantly reduced the frequency of colic, compared with the same formula without the probiotics.9 Another double-blind study found that the probiotic preparation, Lactobacillus reuteri, was an effective treatment for colic in exclusively breast-fed infants.10 In another study, L.reuteri taken once a day was significantly more effective than simethicone, a drug frequently used to treat colic.11 Other double-blind research has confirmed the benefit of probiotics in infants with colic.1213
Probiotic bacteria favorably alter the intestinal microflora balance, inhibit the growth of harmful bacteria, promote good digestion, boost immune function, and increase resistance to infection.14,15 People with flourishing intestinal colonies of beneficial bacteria are better equipped to fight the growth of disease-causing bacteria.16,17Lactobacilli and bifidobacteria maintain a healthy balance of intestinal flora by producing organic compounds—such as lactic acid, hydrogen peroxide, and acetic acid—that increase the acidity of the intestine and inhibit the reproduction of many harmful bacteria.18,19 Probiotic bacteria also produce substances called bacteriocins, which act as natural antibiotics to kill undesirable microorganisms.20