ObjectivesMenopause is a state of low estrogen production which is associated with chronic low‐grade inflammation and higher incidence of overweight. Rice bran (RB) is a nutrient‐dense product of rice milling process that is considered a health improving supplement. The aim of this study was to investigate the influences of RB on the innate immunity of high‐fat diet induce ovariectomized (OVX) obese mice.Methods8 months‐old female mice were randomly divided into OVX sham (SH) group and OVX group. After surgery for one week, mice were randomly assigned to one of the three groups (n=12) and fed the respective diet for four months : SH group and OVX‐control (ONC) group were provided with AIN‐95 control diet containing 10% energy as fat, OVX‐high fat diet (OHF) group was treated with high fat diet (HFD) containing 40% fat, mice in the OVX‐high fat diet with RB (OHFR) group were fed with HFD containing RB (10% wt/wt).ResultsMice in the OHF group showed significantly higher body weight gained, plasma glucose and triglyceride levels than those in the SH and other OVX groups. Compare to the SH and ONC groups, the OHF group had lower splenic natural killer (NK) cells cytotoxic capacity and peripheral blood phagocytes phagocytic ability. The chemotactic ability of leukocytes were also lower in the OHF group. As regard to the OVX group with high‐fat diet, RB supplementation increased NK cells cytotoxic function and phagocytosis ability of phagocytes. Also, the chemotactic ability of neutrophils and macrophage as measured by migration speed and directional persistence were improved in the OHFR group.ConclusionThe findings of this study suggest that RB supplementation improved glucose tolerance and prevented the decline of innate immunity in high‐fat diet induced obese mice with OVX.Support or Funding InformationThis study was supported by research grant MOST 107‐2320‐B‐038‐014 from the Ministry of Science and Technology (Taipei, Taiwan).