While probiotics as a class are generally advantageous to digestion and health, it’s important to note that each genus, species, and strain of probiotic bacteria can often lend its own specific effects to the body. While the evidence for many probiotic effects lacks bulletproof scientific confidence, many are supported by well designed studies. It is worth taking a look at the results of just a few of the multitudinous studies linking the consumption of probiotic bacteria to health benefits. For those of you not used to scientific notation, the name of the bacteria is in italics.
- Lactobacillus casei Shirota - lowered recurrence of bladder cancer.
- L. acidophilus and B. infantis - reduced rates of overall mortality and necrotizing enterocolitis in infants.
- L. rhamnosus GG and Bifidobacterium lactis BB-12 for prevention and L. reuteri SD2222 for treatment - acute diarrhea caused by rotavirus.
- Saccharomyces boulardii - reduced diarrhea in travelers and prevention of diarrhea caused by Clostridium difficile resulting from antibiotic treatment.
- Mix of lactobacilli, bifidobacteria, and streptococcus species - prevented relapse of inflammatory bowel disease symptoms.
- B. lactis HN019 and L. rhamnosus HN001 - enhanced immunity in the elderly
For those that do make the trip successfully, a technology complementary to probiotics has developed to aid their growth. Prebiotics are food ingredients that are not digested by humans but that can be utilized by probiotic bacteria to spur their growth and aid their survival in the digestive tract. They also can provide the building blocks used by bacteria to synthesize compounds beneficial to the host human. Prebiotics generally take the form of carbohydrates and are often also classified as soluble fibers. Popular prebiotics found in many food products include various types of oligosaccharides as well as inulin. An interesting facet of prebiotic function is that the area of the digestive tract in which the prebiotic nourishes its target bacteria is dependent upon the chemical chain length of the prebiotic. Short chain prebiotics are fermented more quickly, allowing them to feed bacteria inhabiting the primary areas of the digestive tract. Longer chain prebiotics ferment more slowly and are consumed by bacteria living further along in the colon. So-called “full-spectrum” prebiotics are comprised of compounds of many different chain lengths and are able to nourish the entire colon.
A final category of food product that is undergoing growth at the current time is the synbiotic. Synbiotic foods contain both probiotic bacteria as well as prebiotic nutrients. The idea is to get both the organism and its food in one shot. While it’s a great idea, always be mindful when choosing synbiotics to ensure that both the bacteria and prebiotics are supplied at a level that has been shown to be beneficial. As with all supplements, unscrupulous companies often include only miniscule amounts of expensive compounds simply for labeling and marketing claims. Do your homework and make sure that you’re getting your money’s worth.