Recent Studies:

Probiotics Help Boost Immunity:

Probiotics and immune health by Yan F, Polk DB, published in Current Opinion in Gastroenterology 2011 Oct;27(6):496-501.

Purpose of review:

The beneficial effects of probiotics have been demonstrated in many diseases. One of the major mechanisms of probiotic action is through the regulation of host immune response. This review highlights the recent scientific research findings that advance our understanding of probiotic regulation of the host immune response with potential application for disease prevention and treatment.

Recent findings:

Probiotic genomic and proteomic studies have identified several genes and specific compounds derived from probiotics, which mediate immunoregulatory effects. Studies regarding the biological consequences of probiotics in host immunity suggested that they regulate the functions of systemic and mucosal immune cells and intestinal epithelial cells. Thus, probiotics showed therapeutic potential for diseases, including several immune response-related diseases, such as allergy, eczema, viral infection, and potentiating vaccination responses.


Probiotics may provide novel approaches for both disease prevention and treatment. However, the results of clinical studies regarding probiotic application are preliminary and require further confirmation.

Vitamin A Helps Integrity of Skin Cells:

The effect of vitamin A on epithelial integrity by McCullough et al, published in The Proceedings of the Nutritional Society, 1999 May;58 (2):289-93.

Vitamin A is the generic term for a variety of fat-soluble substances including retinol, retinyl palmitate and the pro-vitamin A carotenoids such as all-trans-beta-carotene. Vitamin A is commonly known as the anti-infective vitamin and has an essential role in vision and cellular differentiation, the latter providing a unique core mechanism helping to explain the influence of vitamin A on epithelial barriers. Alterations in the epithelial lining of vital organs occur early in deficiency, suggesting a potentially important role for the barrier function.

Catherine J. Field et al, published in the Journal of Leukocyte Biology, 2002;71:16-32, Nutrients and their role in host resistance to infection.

The importance of vitamin A in immune function and protection against infections is well-established and has been reviewed. The different chemical forms of vitamin A (retinol, retinal, retinoic acid) all appear to be involved in its metabolic functions. Vitamin A deficiency can affect host defences directly through its essential functions in metabolism in the various immune cells or indirectly through its role in epithelial cell differentiation and host barrier function.

Vitamin A Helps Boost Immunity:

Catherine J. Field et al, published in the Journal of Leukocyte Biology, 2002;71:16-32, Nutrients and their role in host resistance to infection.

The immune efficacy of supplementing vitamin A on infection rates has been examined in several randomized, double-blind, placebo-controlled trials of malnourished children in various regions of the developing world. Antibody-mediated immunity has been shown to be severely impaired in individuals with vitamin A deficiency. Providing vitamin A supplements has been found to improve the antibody titer response to measles vaccines, maintain gut integrity, lower the incidence of respiratory tract infections and reduce mortality associated with diarrhoea and measles.

This type of support has contributed to the World Health Organization's recommendation that vitamin A supplements be given to all individuals in developing countries who contract measles whether or not they have symptoms of vitamin A deficiency.

In animal studies, vitamin A deficiency inhibits mitogen-stimulated, T-cell proliferation, antigen-specific antibody production and the ability to produce immunoglobulin (Ig)A and IgG . It also reduces the ability of CD4 cells to provide the B-cell stimulus for antigen (Ag)-specific IgG1 responses; limits Th-2-type cytokine-gene expression; decreases the ability of neutrophils to phagocytose infectious organisms (Pseudomonas aeruginosa) and generate active oxidant molecules; and reduces the resistance to several infectious organisms.

Most of these negative effects on host defence that have been associated with low vitamin A status appear to be reversible with restoration of vitamin A status.