Search bioRxiv⌕ Search

Biology subjects

Nagasawa, M.

Publications and source records attributed to Nagasawa, M..

4 recordsLinked to original sources

Comparative analysis based on shared amplicon sequence variants reveals that cohabitation influences gut microbiota sharing between humans and dogs

IntroductionThe One Health concept is a comprehensive understanding of the interaction between humans, animals, and the environment. The cohabitation of humans and dogs positively affects their physical, mental, and social well-being. It is recognized as an essential factor from the One Health perspective. Furthermore, a healthy balance in the gut microbiome is essential for good health, and the sharing of gut microbes between humans and dogs may positively impact the health of both hosts. Therefore, elucidating the sharing of gut bacteria between humans and dogs is important for understanding One Health. However, most studies have examined sharing at the taxonomic level, and it remains unclear whether the same bacteria are transferred between humans and dogs, and whether they mutually influence each other. MethodsHere, microbiome analysis and 16S rRNA gene amplicon sequence variant (ASV) analysis was performed to address this question. Results16S rRNA gene ASVs analysis indicated that gut microbes have been transferred between humans and dogs. The overall structure of the gut microbiota within human-dog pairs remained unchanged after three months of adaptation. However, some ASVs were shared within human-dog pairs. Many shared ASVs were highly abundant within each host, and this high abundance may be considered a factor that influences bacterial transfer between hosts. DiscussionOur results demonstrate the possibility of the direct transfer of gut bacteria between humans and dogs, providing an important insight for achieving good health through human-dog cohabitation.

microbiology↗

Beacon-based sleep status and physical activity monitoring in humans.

One out of every five people in Japan is dissatisfied with their sleep and various diseases caused by lack of exercise have been pointed out, but there are few effective remedies for these problems. In this study, we aimed to develop a simple method for measuring behavioral sleep patterns and physical activity using a beacon accelerometer wirelessly connected with a smartphone. A sleep prediction model was created comparing the data obtained from the accelerometer with the sleep status data obtained by a previously validated sleep monitoring system. The Random Forest model was able to classify sleep and wakefulness with a 97.4% and 85.4% precision, respectively, which were comparable to those of conventional acceleration-based sleep monitoring devices. Additionally, the same data acquisition method was used to classify exercise intensity into seven levels and a high correlation (r=0.813, p<0.0001) was found when comparing the classified exercise intensity to metabolic equivalent (MET) values. This suggests that the proposed method can be used for accurate measurement of both behavioral sleep and physical activity classifying over a long period of time.

physiology↗

The Intestinal Microbiome, Dietary Habits, and Physical and Psychological Resilience in Postpartum Women

The population of postpartum women suffering from mental illness is increasing steadily, particularly under conditions of the COVID-19 pandemic. Identifying factors that contribute to resilience in postpartum women is urgently needed to decrease risks of poor physical and psychological functioning. Studies have linked variations in the intestinal microbiota to depression in clinical samples, but the impacts in postpartum women in a Japanese population are unknown. We conducted two studies to examine the links between intestinal microbiota, physical condition, and psychological state in nonclinical, postpartum Japanese women. Our results show that decreasing Lachnospira and alpha diversity of microbiome is related to high mental health risk (i.e., parenting stress and/or depression). Psychological resilience and physical conditions were associated with relative abundances of genera Blautia, Clostridium, Eggerthella. This study contributes to further understanding of the gut-brain axis mechanisms and supports proposals for interventions to enhance resilience in postpartum women.

microbiology↗

Oxytocin and Emotional Tear in Dogs

In humans, tear volume increases in emotional arousal. No studies have investigated the relationship of emotional arousal and tear volume in animals. We measured tear volume in dogs before and after reunion with their owners. Tear volume increased significantly during owner, but not familiar non-owner, reunions but not during reunions with familiar non-owners. When oxytocin instillation was applied to dogs, the tear volume increased, suggesting that oxytocin can mediate the emotion-induced tear secretion in dogs. When the photos of dogs face in which artificial tear was applied to the dogs eyes, the positive impression of these photo increased. These suggest that emotional tear can facilitate human-dog emotional connection.

animal behavior and cognition↗