Resistant Starch Attenuates Bone Loss in Ovariectomised Mice by Regulating the Intestinal Microbiota and Bone-Marrow Inﬂammation
The intestinal microbiota may regulate bone metabolism by reducing levels of pro-inﬂammatory cytokines, and T cells in bone tissues of oestrogen-deﬁcient mice have been reported. Resistant starch (RS) is a type of dietary ﬁbre and results in changes in the composition of the gut microbiota.
We evaluated the effects of RS supplemented in diets on intestinal microbial composition, bone mineral density, and inﬂammatory-gene expression in the colon and bone marrow of ovariectomised (OVX) mice. OVX mice were divided randomly into three groups: OVX control, OVX fed a 20% high amylose corn starch (HAS) diet, and OVX fed a 20% acid-hydrolysed HAS (AH-HAS) diet. HAS and AH-HAS diets contained 6.8% and 12% of RS, respectively. After 6 weeks, treatment with HAS or AH-HAS increased the abundance of Biﬁdobacterium spp. in faeces. The AH-HAS diet tended to upregulate mRNA expression of interleukin (IL)-10 in the colon, and downregulate expression of receptor activator of nuclear factor kappa-B ligand and IL-7 receptor genes in the bone marrow of OVX mice. AH-HAS treatment attenuated ovariectomy-induced bone loss. These ﬁndings suggest that AH-HAS might change the microbiota and immune status of the bone marrow, resulting in attenuated bone resorption in OVX mice.