Sleep is essential for our health. Short sleep is known to increase disease risks via imbalance of intestinal microbiota, dysbiosis. However, mechanisms by which short sleep induces dysbiosis remain unknown. Small intestinal Paneth cell regulates the intestinal microbiota by secreting antimicrobial peptides including α-defensin, human defensin 5 (HD5). Disruption of circadian rhythm mediating sleep-wake cycle induces Paneth cell failure. We aim to clarify effects of short sleep on HD5 secretion and the intestinal microbiota. Fecal samples and self-reported sleep time were obtained from 35 healthy middle-aged Japanese (41 to 60-year-old). Shorter sleep time was associated with lower fecal HD5 concentration (r = 0.354, p = 0.037), lower centered log ratio (CLR)-transformed abundance of short-chain fatty acid (SCFA) producers in the intestinal microbiota such as [Ruminococcus] gnavus group (r = 0.504, p = 0.002) and Butyricicoccus (r = 0.484, p = 0.003), and lower fecal SCFA concentration. Furthermore, fecal HD5 positively correlated with the abundance of these genera and SCFA concentration. These findings suggest that short sleep relates to disturbance of the intestinal microbiota via decreased HD5 secretion.

The Dietary Inflammatory Index (DII) is a comprehensive, literature-derived index for assessing the effect of dietary constituents on inflammatory biomarkers. Several studies have shown an association between DII score and mortality, but there are limited prospective studies in Asian populations. The aim of this study was to investigate the association between DII score and risk of all-cause, total cardiovascular disease (CVD), stroke, coronary heart disease (CHD), total cancer, digestive cancer, and noncancer/non-CVD mortality in the Japanese population. A total of 58,782 Japanese participants aged 40-79 y who were enrolled in the Japan Collaborative Cohort Study during 1988-1990 were included in the analysis. DII scores were calculated based on a food-frequency questionnaire. HRs and 95% CIs for mortality according to DII quintiles were estimated using Cox proportional hazards models. During the median follow-up period of 19.3 y, a total of 11,693 participants died. The multivariable HR for all-cause mortality for the highest compared with the lowest DII quintiles was 1.13 (95% CI: 1.05, 1.21). For CVD mortality, the highest multivariable HRs were 1.30 (95% CI: 1.13, 1.49), 1.29 (95% CI: 1.05, 1.59), and 1.30 (95% CI: 0.96, 1.76) for total CVD, stroke, and CHD, respectively. No significant associations were observed between DII and risk of total cancer, digestive cancer, and noncancer/non-CVD mortality. Our findings suggest that a higher DII was associated with an increased risk of all-cause and CVD mortality among Japanese adults.

Several studies have evaluated associations between the characteristics of patients with esophageal and gastric cancer and survival, but these associations remain unclear. We described the distribution of demographic and lifestyle factors among patients with esophageal and gastric cancer in Japan, and investigated their potential effects on survival. Between 2003 and 2007, 24- to 95-year-old Japanese patients with esophageal and gastric cancer were enrolled in the BioBank Japan Project. The analysis included 365 patients with esophageal squamous cell carcinoma (ESCC) and 1574 patients with gastric cancer. Hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality were estimated using medical institution-stratified Cox proportional hazards models. During follow-up, 213 patients with ESCC (median follow-up, 4.4 years) and 603 patients with gastric cancer (median follow-up, 6.1 years) died. Among patients with ESCC, the mortality risk was higher in ever drinkers versus never drinkers (multivariable HR = 2.37, 95% CI: 1.24, 4.53). Among patients with gastric cancer, the mortality risk was higher in underweight patients versus patients of normal weight (multivariable HR = 1.66, 95% CI: 1.34, 2.05). Compared to patients with gastric cancer with no physical exercise habit, those who exercised ≥3 times/week had a lower mortality risk (multivariate HR = 0.75, 95% CI = 0.61, 0.93). However, lack of stage in many cases was a limitation. Among patients with ESCC, alcohol drinkers have a poor prognosis. Patients with gastric cancer who are underweight also have a poor prognosis, whereas patients with physical exercise habits have a good prognosis.

Development of an accurate and efficient dietary method is required for national nutrition surveys. Some countries conduct dietary surveys and combine 24-h dietary records or 24-h dietary recalls with dietary questionnaires. This scoping review aimed to summarize studies that used results from national surveys that combined detailed dietary surveys (dietary records or 24-h dietary recall) and dietary questionnaires and identify the purpose of combining the two methods. The PubMed database and manual searches were used for the literature review. We extracted 58 articles from 16 national nutrition surveys from 14 countries. Most studies used 24-h dietary recall for detailed dietary surveys and the food frequency questionnaire (FFQ) or food propensity questionnaire (FPQ) for questionnaire surveys. Among 37 studies from eight countries, the purpose of combining the two dietary survey methods was to estimate energy and nutrient intakes from detailed dietary surveys and habitual food intake from questionnaires. These findings are useful as a reference when introducing new dietary survey methods in future national nutrition surveys.

Consumption of dairy products in the usual diet may be important for improving the overall quality of dietary intake. This study aimed to assess the difference in nutrient intake adequacy according to the intake of dairy products based on a 1-day weighed dietary record of Japanese adults from the 2016 National Health and Nutrition Survey. Nutritional adequacy was determined based on the Dietary Reference Intakes for Japanese 2015, with 2 goals: Tentative dietary goals (DG) for preventing lifestyle-related diseases, and the estimated average requirement (EAR). According to the dairy products consumption, participants were categorized into three groups (milk, other dairy product, or non-dairy), and the total number of those not meeting DG and EAR was compared. Non-dairy consumers were less likely to meet both DG and EAR compared to dairy consumers. Dairy consumers were more likely to exceed the DG for saturated fat than non-dairy consumers. Japanese adult dairy consumers were more likely to have adequate nutritional intake than non-dairy consumers, especially for calcium. We also observed a higher saturated fat intake in dairy consumers, which might be due to a certain dietary pattern in this group. Further investigation is needed to determine dairy intake and its influence on dietary quality among the Japanese population.

Recently, aging is considered a risk factor for various diseases. Although changes in the intestinal microbiota along with aging are thought to associate with the increased disease risk, mechanisms that cause age-related transition of the intestinal microbiota remain unknown. This study aims to clarify relationships between the amount of human defensin 5 (HD5), a Paneth cell α-defensin, which is known to regulate the intestinal microbiota, and age-related differences of the intestinal microbiota composition. Fecal samples from 196 healthy Japanese (35 to 81 years old) were collected and measured HD5 concentration. HD5 concentration in the elderly group (age > 70 years old) was significantly lower than the middle-aged group (age ≤ 70 years old). Furthermore, individual age was negatively correlated with HD5 concentration (r = − 0.307, p < 0.001). In β-diversity, the intestinal microbiota of the elderly showed a significantly different composition compared to the middle-aged. At the genus level, relative abundance of Collinsella, Alistipes, Peptococcaceae; unassigned, Lactobacillus, Lactococcus, Weissella, Christensenellaceae R-7 group, Megasphaera, and [Eubacterium] eligens group was significantly higher, and Lachnospiraceae; unassigned, Blautia, Anaerostipes, Fusicatenibacter, Dorea, and Faecalibacterium was significantly lower in the elderly compared to the middle-aged. In addition, HD5 concentration was negatively correlated with Alistipes, Peptococcaceae; unassigned, and Christensenellaceae R-7 group and positively correlated with Lachnospiraceae; unassigned and Dorea. These results provide novel insights into the immunosenescence of enteric innate immunity, indicating low HD5 is suggested to contribute to the age-related differences in the intestinal microbiota and may relate to increased risk of diseases in elderly people.