Abstract
BACKGROUND: This study aims to investigate the effect of feeding low-fat diet (LFD) to diet-induced obesity (DIO) mice lacking TLR5 (TLR5(-/-)), which have a tendency to develop glucose intolerance with increased adiposity, compared to that in C57BL/6 mice. RESULTS: TLR5(-/-) and C57BL/6 male mice were divided into three subgroups: (1) control, mice were fed a standard AIN-76A (fat: 11.5 kcal%) diet for 12 weeks; (2) DIO, mice were fed a 58 kcal% high-fat diet (HFD) for 12 weeks; and (3) diet, mice were fed a HFD for 8 weeks to induce obesity and then switched to a 10.5 kcal% LFD for 4 weeks. The glucose intolerance in DIO TLR5(-/-) mice was more significant than that in DIO C57BL/6 mice and was not attenuated by a switch to the LFD. Weight-reduction with LFD had significantly decreased the epididymal fat mass in C57BL/6 mice but not in TLR5(-/-) mice. In addition, the LFD-fed TLR5(-/-) mice showed significantly higher expression of ghrelin in the serum and resistin in the epididymal fat than that in C57BL/6 mice. CONCLUSIONS: This study demonstrated that TLR5 gene knockout impairs some effects of weight-reduction in DIO.