Friendly bacteria, or probiotics, consist of live microorganisms that reside in the body and enhance the health of their host. Certain strains of probiotic bacteria can affect the immune system. Friendly bacteria degrade toxic substances and allergenic food proteins in the digestive tract. They help regulate cholesterol and triglyceride uptake, make certain vitamins and provide signals that limit inflammation of the digestive tract. In addition, laboratory and clinical studies have shown that probiotics affect white blood cells, antibody responses, infectious diseases and tumor growth, according to the text "Nutrition and Immune Function."
Lactobacillus Acidophilus
Lactobacillus acidophilus occurs naturally in the mouth and intestines. In food, it occurs in fermented milks, unfermented milks with added cultures, ice cream, frozen yogurt and some cheeses. According to the website Probiotics.org, Lactobacillus acidophilus helps the body absorb nutrients such as the B vitamins, vitamin K, calcium and fatty acids; reduces lactose intolerance; and decreases allergic responses.
Bifidobacterium Bifidum
This bacteria inhabits the colon and helps control the increase of pathogenic bacteria. It enhances the immune system and aids digestion. Like Lactobacillus acidophilus, Bifidobacterium bifidum occurs in fermented milks, unfermented milks as an added culture, frozen yogurt, cheeses and ice cream.
Lactobacillus Rhamnosus
Lactobacillus rhamnosus, one of the most widely studied probiotics, survives and thrives in harsh conditions. It assists digestion in the intestinal tract and also assists the immune system to combat pathogens in the intestinal tract. Lactobacillus rhamnosus acts as a natural preservative in yogurt. According to probiotics.com, Lactobacillus rhamnosus reduces the inflammatory response to dairy products in lactose-intolerant people who consume milk.
According to "Nutrition and Immune Function," Lactobacillus rhamnosus not only decreases inflammatory response but also decreases expression of allergy reactions in milk-hypersensitive subjects and increases antibody responses to harmful bacteria.
Lactobacillus Casei
Lactobacillus casei promotes the growth of other beneficial bacteria such as Lactobacillus acidophilus and prevents overgrowth of pathogenic bacteria in the body. According to "Nutrition and Immune Function," research indicates that Lactobacillus casei increases cellular immune responses and decreases tumor recurrence in adult bladder cancer patients following resection.
Saccharomyces Boulardii
Saccharomyces boulardii, a strain of yeast, helps control diarrhea. It has been used to treat a condition caused by the overgrowth of the resistant Clostridium difficile bacteria after antibiotics have killed other nonresistant bacteria and upset the balance of intestinal microorganisms.
References
- Probiotics.org: Probiotic Strains
- "Nutrition and Immune Function"; P.C. Calder, C.J. Field and H.S. Gill; 2002
- "Understanding Nutrition, Ninth Edition"; Eleanor Noss Whitney and Sharon Rady Rolfes; 2002
