Effects of a new immune-modulating diet enriched with whey-hydrolyzed peptide, fermented milk, and isomaltulose on gut associated lymphoid tissue in mice

SummaryAimTo examine whether an enteral immune-modulating diet (IMD) enriched with whey-hydrolyzed peptide, fermented milk, and isomaltulose enhances gut associated lymphoid tissue (GALT) mass and function as compared with a standard enteral diet (STD).MethodsMale ICR mice were randomized into the IMD (n = 10) or STD (n = 10) group. After 7 days of each feeding protocol, whole small intestines were harvested. GALT lymphocytes from Peyer's patches (PPs), intraepithelial spaces (IE) and the lamina propria (LP) were isolated, counted and subjected to phenotypic determination by flowcytometry (αβTCR+, γδTCR+, CD4+, CD8+ and B cells). In another set of mice (IMD; n = 13, STD; n = 13), immunoglobulin A (IgA) levels of small intestinal, nasal and broncho-alveolar washings were measured with ELISA.ResultsTotal lymphocyte numbers in PPs and LP and absolute numbers of B cells in PPs, γδTCR + cells in IE and αβTCR+, γδTCR+, CD4+, and CD8+ cells in LP were significantly higher in the IMD than in the STD group. IgA levels of small intestinal washings were significantly higher in the IMD than in the STD group with no differences in respiratory tract IgA levels.ConclusionThe new IMD increases GALT mass and gut IgA levels as compared with STD.