Comparison of functional assay and microarray analysis for determination of Lactobacillus acidophilus LAFTI L10 induced gut immune responses in mice

Probiotics are emerging as functional food supplements that are known to promote specific health benefits beyond basic nutritional functions. The current study evaluated the ability of Lactobacillus acidophilus LAFTI L10 in modulating gut immune responses in mice. Mice were orally fed with L. acidophilus for 14 days, during which they were immunized twice with 10 mu g of cholera toxin (CT). The immunoglobulin (Ig)-A response to CT in intestinal fluid and serum were significantly enhanced by L. acidophilus. Mice fed with L. acidophilus increased the number of interferon (IFN)-gamma, interleukin (IL)-6 and IL-10 producing cells in the small intestine. Microarray analysis is known to be more sensitive and predictive than functional assays. For this reason, gene expression analysis was chosen as an alternative approach in determining the immunomodulatory effects of L. acidophilus. Gene expression profiles in small intestine of mice fed with L. acidophilus did not uncover the effects related to immune functions that were detected through functional assays. Therefore, functional assays are superior in predicting the immunomodulatory responses of probiotic bacteria. (C) 2009 Elsevier Ltd. All rights reserved.