Trehalose ingestion modifies mucosal immune responses of the small intestine in mice

Trehalose has been utilized as a supplement to various products such as food and cosmetics, and has recently been reported to have multiple biological functions in vitro and in vivo. We have previously found that trehalose administered orally inhibits mouse osteoclastogenesis induced by estrogen-deficiency or by injection of lipopolysaccharide (LPS). In this study, we examined whether oral administration of trehalose to mice produced changes in the Peyer's patches (PP) of the small intestine, that are essential for mucosal immune responses, to clarify the inhibitory mechanism of trehalose on osteoclastogenesis. Male C3H/HeN mice were orally administered trehalose 1 g/kg for 5 consecutive days. Interestingly, trehalose administration caused a significant decrease in the total number of PP lymphocytes (PPL) and in the spontaneous release of interleukin (IL)-6 by PPL compared with those of controls, without inducing apparent pathological damage. Moreover, proliferation and interferon (IFN)-gamma production by PPL in response to LPS tended to increase compared with those of the control group. Considering that IL-6 and IFN-gamma are factors associated with bone metabolism, our results suggest the possibility that trehalose ingestion may modify the intestinal immune environment, resulting in altered systemic immunity and bone metabolism.