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.

Short-chain fatty acids, including acetate, propionate, and butyrate are metabolites of dietary fibre produced by microbiota in the large intestine, have been proposed to contribute to effects on bone homeostasis. However, it is unclear whether they are used in osteoblasts and directly affect bone formation. We investigated whether short-chain fatty acids are absorbed in osteoblast cells and influence early osteoblastic differentiation using MC3T3-E1 cells. Acetate and propionate upregulated alkaline phosphatase activity, which is an osteoblast differentiation marker, and acetate upregulated alkaline phosphatase mRNA expression after treatment for 9 days, whereas butyrate did not in MC3T3-E1 cells. Butyrate was absorbed more rapidly and to a greater extent than acetate and propionate. These results indicate that short-chain fatty acids were used in osteoblastic cells, and particularly acetate and propionate directly upregulated differentiation in primary osteoblasts. Therefore, acetate and propionate might be useful for maintaining a positive balance of bone turnover.

It is well known that physical inactivity during space flight or prolonged bed rest causes rapid bone loss. Soy isoflavones (ISOs) and resveratrol (RES) have been reported to be useful to maintain a positive balance for bone turnover. Therefore, we examined the combined effects of ISO and RES on bone loss that was induced by hindlimb-unloading in mice. Female eight-week-old ddY mice were divided into the following six groups (n = 6–8 each): normally housed mice, loading mice, hindlimb-unloading (UL) mice fed a control diet, UL mice fed a 0.16% ISO conjugates, UL mice fed a 0.15% RES diet, and UL mice fed a 0.16% ISO and 0.15% RES diet. After three weeks, femoral bone mineral density was markedly decreased in unloading mice. The combination of ISO and RES prevented bone loss and especially maintained the trabecular bone mineral density more effectively compared with cortical bones. ISO and/or RES inhibited the increase in the RANKL/OPG expression ratio in bone marrow cells in UL mice. These results suggest that the combination of ISO and RES had a preventive effect against bone loss induced by hindlimb-unloading in mice. These osteoprotective effects of ISO and RES may result from the inhibition of bone resorption.

Numerous nutrient profiling models (NPMs) exist worldwide, but Japan lacks an official NPM. Using the Australian and New Zealand Health Star Rating (HSR) as a reference, “Processed Foods in Japan version 1.0” (NPM-PFJ (1.0)) was developed to fit Japanese food culture and policies. In total, 668 processed foods from the Standard Tables of Food Composition in Japan were analyzed, excluding seasonings/spices, fats/oils, alcoholic beverages, and infant food. The NPM-PFJ (1.0) scoring algorithm was adapted from HSR, with revised reference values for energy, saturated fat, total sugars, sodium, protein, and dietary fiber in alignment with Japanese standards. Reference values for fruits, vegetables, nuts, and legumes (fvnl) remained unchanged. Median scores were 4.5 for HSR and 5.0 for NPM-PFJ (1.0), showing high correlation (r = 0.939, p < 0.01). Thereafter, food categories familiar and meaningful in Japan were defined based on a hierarchical cluster analysis of scoring patterns, creating six categories with distinct characteristics. Finally, the rating algorithm for NPM-PFJ (1.0) was created using each group’s score distribution (10th percentile). The NPM-PFJ (1.0) was developed through a fully transparent and evidence-based process and is expected to facilitate the reformulation of food products by food industries and help consumers easily access healthier processed foods. This model marks a significant step forward in developing an NPM tailored to Japanese food culture and health policies, with the potential to enhance public health.

To address the rising incidence of non-communicable diseases (NCDs) and promote healthier eating habits, Japan requires a culturally tailored Nutrient Profile Model. This study aimed to develop a Nutrient Profile Model for Dishes in Japan version 1.0 (NPM-DJ (1.0)) that corresponds to the nutritional issues and food culture in Japan. The aim of the NPM-DJ (1.0) was to promote the health of the general population, and to prevent the increase in NCDs in Japan. The NPM-DJ (1.0) categorizes dishes into staples, sides, mains, mixed dishes, and mixed dishes with staples. The model evaluates dishes based on energy, saturated fats, sugars, and sodium as restricted nutrients, while considering protein, dietary fiber, and the weight of certain food groups as recommended nutrients. The distribution of the overall score for each dish category was analyzed and a rating algorithm was created. The baseline, modification points, and final scores were significantly lower for side dishes than for staple dishes. In contrast, the baseline points and final scores were significantly higher for mixed dishes with staple. The model effectively differentiated nutritional profiles across five dishes categories, which may promote healthier dish reformulation by food businesses operators and encourage consumers to select healthier dishes.

Presenteeism is a problem that needs to be solved urgently, both for individual workers and for society overall. In this report, we propose the concept of MHC, which refers to mild mental and physical complaints subjectively perceived by individuals that are not caused by illness. We also planned to examine what kind of physical and mental disorder MHC is and whether food is effective as a method of self-care for MHC. First, we conducted “the comprehensive survey to establish an integrated database of food, gut microbiome, and health information” (the “Sukoyaka Health Survey”) and obtained data on psychosomatic disorders and intakes of dietary nutrients. As a result, through factor analysis and item response theory analysis, we found the following specific examples of MHC: lack of vigor, irritability, fatigue, and somatic complaints. In addition, analysis of the relationship between these four MHC levels and the intake dietary nutrients indicated that they are closely related and that MHC levels can be improved by consuming sufficient amounts of multiple nutrients.