Suppression of allergy development by habitual intake of fermented milk foods, evidence from an epidemiological study

Abstract

Background: The interest in anti-allergic immunoregulation by lactic acid bacteria (LAB) has been growing over the last few decades. However, little is known about the effect of habitually intake of fermented milk on allergy development. Methods: An epidemiological study was carried out on the first-year junior high school students in Wakayama Prefecture. Analyses were performed to investigate the relationships among eating habits of fermented milk or fermented soybean foods and the presence of atopic diseases. Serum levels of total IgE values, specific IgE to house dust mite and Japanese cedar pollen in these subjects were evaluated to clarify atopic status. Analyses were performed on the data of 134 subjects. Results: Serum total IgE levels were found to be significantly lower in those subjects habitually eating yogurt and/or fermented milk drinking, in comparison with those who do not habitually eat such fermented milk foods. Subjects with habitual intake of these fermented milk foods were significantly lower in having various allergy diseases compared with those without such an eating habit. However, no difference was found on the total IgE titers and having allergy diseases between subjects with or without habitual intake of Natto, a fermented soybean food. Conclusion: These findings supported the idea that intestinal bacteria such as lactic acid bacteria and bifidobacteria involve in regulation of allergy development. Our results indicated the need of further scale-up epidemiological study to verify the present finding.