More than 400 strains of friendly flora, or probiotics, work with our bodies to fight off disease in a variety of ways. In fact, good bacteria secrete antibacterial substances, competing with pathogens to help us withstand a number of diseases. Probiotics also help balance the immune system, fighting allergies and reducing the risk of cancer.

For Infants and Children

Breast milk contains probiotics, critical since infants’ immune systems are still undeveloped. “For babies who can’t be breastfed, supplementation with probiotics has been found to establish better intestinal health,” says Earl Mindell, RPh, PhD. “If you would like to try this with your own child, do so with the guidance of your pediatrician,” he adds.

A good deal of research on probiotics focuses on their benefits for diarrhea, especially in children. The most extensively investigated strain, Lactobacillus rhamnosus, shortened the duration of diarrhea due to rotavirus in one randomized, double-blind, placebo-controlled trial with infants and young children. Other clinical trials find that Lactobacillus GG and Saccharomyces boulardii significantly lessen the incidence of diarrhea caused by antibiotic drugs.

Fighting Allergies

Probiotics have proved effective in treating young children with moderate to severe dermatitis. Swedish research finds differences in microflora between healthy and allergic infants. Experimental research suggests that beneficial bacteria exert antiallergic effects on immune and intestinal epithelial cells, protecting the gut’s defense barrier that prevents unwanted substances from moving into the bloodstream. Probiotics appear to reduce intestinal inflammation, which can cause tiny holes in the intestinal wall, allowing food particles to enter the bloodstream. Since the immune system works to rid the body of these particles, friendly bacteria are useful in preventing immune reactivity and allergic reactions.

Digestive Health

Not surprisingly, probiotics help prevent and treat inflammatory bowel disease (IBD), while supporting the internal ecosystems of those with Crohn’s disease, irritable bowel syndrome (IBS), and ulcerative colitis. And the role of good bacteria extends to healthy individuals, too.

Without probiotics, digestion, absorption, and detoxification cannot proceed normally. This explains why antibiotics usually cause digestive problems, since these drugs kill off beneficial as well as harmful bacteria. Many probiotics increase the acidity of the GI tract, protecting against pathogens and yeasts. Candida albicans yeasts in the digestive tract and mucous membranes quickly grow and spread when the levels of good bacteria fall, setting the stage for severe yeast overgrowth throughout the body and compromising immunity.

Other Benefits

Friendly flora also protect against H. pylori bacteria, implicated in stomach ulcers and cancer. Not only do probiotics fight infection by killing off bad bacteria, but they also enhance the activity of white blood cells (which attack pathogens) and support cytokine production (which helps cells communicate effectively). Animal research suggests that friendly bacteria help inhibit the growth of cancer caused by toxic chemicals and may even protect against colon cancer.

Beneficial bacteria manufacture a host of nutrients in the body: amino acids, antioxidants, B complex vitamins, vitamin K, and short-chain fatty acids. Bacterial cultures used to ferment foods make nutrients more bioavailable in the body and can help people with lactose intolerance enjoy yogurt and other fermented dairy products.