Specific Strains of Probiotics Can Support Healthy Immunity

Article by Don Goldberg

By Neil Edward Levin, CCN, DANLA

Senior Nutrition Education Manager of NOW® Health Group

Past President of American Nutrition Association

The intestinal epithelium is a continuous physical-functional barrier protecting our internal environment against undesirable external influences.  Surface disruptions cause the loss of epithelial cells, degrading our immune barriers.  Disruptive factors include reactions to dietary components, gastrointestinal secretory substances, and microbes (xenobiotics).  

Probiotics are defined as products which contain viable non-pathogenic microorganisms able to confer health benefits to the host.  In a healthy adult, cells of microorganisms are estimated to outnumber human cells by a factor of 10:1.  Aging changes our gut microbiota (microbial community) composition and alters immune system function.  There are many studies of adults linking altered gut microbiota with health problems such as digestive, immune, and bowel issues.  Probiotics, prebiotics, and related factors may affect the health status of seniors by modifying their G.I. environment and improving the composition of the microbial community, which modulates the immune system.  

Bacteria form colonies and communicate both among themselves and with intestinal cells. Communication between Natural Killer and Dendritic (antigen-presenting) cells is expedited via immunomodulation by certain bacterial probiotics such as Lactobacillus acidophilus.  Immune problems may be caused by miscommunication between bacteria and our cells, especially certain autoimmune reactions, unless a healthy microbial community is maintained. 

Each probiotic strain has specific health benefits, but doesn’t provide every health benefit associated with general probiotic use.  A probiotic’s origin (soil, food, human feces) also doesn’t guarantee benefits because “human strains” originate in food, soil, or water and to be an oral probiotic a strain must be:

• An identifiable safe species
• A specific microbial strain proven to have human health benefits
• Bile- and acid-resistant to reach the gut intact
• Viable throughout processing and in retail packaging to deliver the benefits to consumers, with clear label potency claims and storage requirements (preferably shelf stable for convenience)

Research indicates that some probiotic strains promote health-related functions, including normal host resistance to microbes.  Immune competency requires a balanced interaction of microflora, gut epithelium (the cells lining the G.I. tract), and our immune cells.  Disruption of these structural interactions contributes to potential immune dysfunction and short-term inflammation. Lactobacillus bacteria have been successful in helping address these issues.  

Here are two examples of the clinical science supporting strain-specific probiotic bacteria:

Lactobacillus acidophilus NCFM®: 

In a study of healthy children 3-5 years old without known pre-existing diseases, probiotic supplementation with L. acidophilus NCFM® (10 billion CFU/day) maintained healthy immune system function better than the placebo group.*  Daily supplementation of L. acidophilus NCFM® for 6 months was a safe, effective way to reduce the number of missed school days.²* 

In mouse studies, oral administration of L. acidophilus NCFM® effectively maintained healthy cellular health in the colon.*  

Lactobacillus acidophilus NCFM® has several positive characteristics.  It survives passage through the G.I. tract (is inherently acid resistant) and positively influences the gut microflora.* In healthy adults, consumption increases the number of Lactobacilli in the feces, indicating survival after oral supplementation.*  

Bifidobacterium lactis Bl-04: 

In a pilot study of healthy adults, B. lactis Bl-04 (20 billion CFU/day) modulated immune responses and induced a faster increase in serum IgG concentrations than several other probiotic strains or a placebo.*  

Lactobacillus acidophilus NCFM® combined with Bifidobacterium lactis Bl-04: 

In a 4-month, double-blind, randomized study, 47 children with birch pollen allergy received this probiotic combination (5 billion CFU/day) or placebo.  The allergy changed fecal microbiota composition.  Symptoms were recorded in a diary.  The strains were selected based on their inflammatory modulating properties and immune supporting effects.* Blood samples were taken for analysis of cytokines and eosinophils, and nasal swabs for eosinophils.  Fecal samples were analyzed for microbiota components, calprotectin, and IgA.  This specific combination of probiotics prevented pollen-induced infiltration of eosinophils into nasal mucosa, with a trend for reduced nasal symptoms.* 

These examples show the power of specific strains of probiotic bacteria to support healthy immune system function.*

* These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.