Intestinal microbiome and maternal mental health: preventing parental stress and enhancing resilience in mothers.

The number of mothers suffering from mental illness is increasing steadily, particularly under conditions of the coronavirus pandemic. The identification of factors that contribute to resilience in mothers is urgently needed to decrease the risks of poor physical and psychological health. We focused on the risk of parenting stress and psychological resilience in healthy mothers with no psychiatric and physical disorders and conducted two studies to examine the relationships between intestinal microbiota, physical condition, and psychological state. Our results showed that alpha diversity and beta diversity of the microbiome are related to high parenting stress risk. Psychological resilience and physical conditions were associated with relative abundances of the genera Blautia, Clostridium, and Eggerthella. This study helps further understand the gut-brain axis mechanisms and supports proposals for enhancing resilience in mothers.

Altered Gut Microbiota Composition Is Associated with Difficulty in Explicit Emotion Regulation in Young Children.

Executive function (EF) consists of explicit emotion regulation (EER) and cognitive control (CC). Childhood EER in particular predicts mental and physical health in adulthood. Identifying factors affecting EER development has implications for lifelong physical and mental health. Gut microbiota (GM) has attracted attention as a potential biomarker for risk of physical and mental problems in adulthood. Furthermore, GM is related to brain function/structure, which plays a crucial role in emotional processing. However, little is known about how GM compositions are associated with the development of emotion regulation in early childhood. Therefore, in this study, we examined 257 children aged 3-4 to investigate links between GM and risk to EF. EF was measured using the Mother-Reported Behavior Rating Inventory of Executive Function-Preschool version. GM composition (alpha/beta diversity and genus abundance) was evaluated using 16S rRNA gene sequencing and compared between EF-risk and non-risk groups. Our results show that children with EER-risk (an index of inhibitory self-control) had a higher abundance of the genera Actinomyces and Sutterella. Although we have not established a direct link between GM and CC risk, our findings indicate that GM of preschoolers is closely associated with emotional processing and that EERrisk children have more inflammation-related bacteria.

Long-Term Effects of a Ketogenic Diet for Cancer.

A ketogenic diet has been proposed as a potential supportive therapy for cancer patients, although its long-term influence on survival rates remain controversial. In our previous report, we presented promising results for 37 of 55 patients with advanced cancer enrolled between 2013 and 2018 who remained on a ketogenic diet for at least 3 months. We followed all 55 patients until March 2023 and analyzed the data up to March 2022. For the 37 patients with previously reported promising results, the median follow-up period was 25 (range of 3-104) months and 28 patients died. The median overall survival (OS) in this subset of 37 patients was 25.1 months and the 5-year survival rate was 23.9%. We also evaluated the association between the duration of the ketogenic diet and outcome in all 55 patients, except for 2 patients with insufficient data. The patients were divided into two groups: those who followed the diet for ≥12 months (n = 21) and those who followed it for <12 months (n = 32). The median duration of the ketogenic diet was 37 (range of 12-99) months for the ≥12 months group and 3 (range of 0-11) months for the <12 months group. During the follow-up period, 41 patients died (10/21 in the ≥12 months group and 31/32 in the <12 months group). The median OS was 19.9 months (55.1 months in the ≥12 months group and 12 months in the <12 months group). Following the inverse probability of treatment weighting to align the background factors of the two groups and make them comparable, the adjusted log-rank test showed a significantly better OS rate in the group that continued the ketogenic diet for a longer period (p < 0.001, adjusted log-rank test). These results indicate that a longer continuation of the ketogenic diet improved the prognosis of advanced cancer patients.

Development of the Paternal Brain in Humans throughout Pregnancy.

Previous studies have demonstrated that paternal caregiving behaviors are reliant on neural pathways similar to those supporting maternal care. Interestingly, a greater variability exists in parental phenotypes in men than in women among individuals and mammalian species. However, less is known about when or how such variability emerges in men. We investigated the longitudinal changes in the neural, hormonal, and psychological bases of expression of paternal caregiving in humans throughout pregnancy and the first 4 months of the postnatal period. We measured oxytocin and testosterone, paternity-related psychological traits, and neural response to infant-interaction videos using fMRI in first-time fathers and childless men at three time points (early to mid-pregnancy, late pregnancy, and postnatal). We found that paternal-specific brain activity in prefrontal areas distinctly develops during middle-to-late pregnancy and is enhanced in the postnatal period. In addition, among fathers, the timing of the development of prefrontal brain activity was associated with specific parenting phenotypes.

A multidimensional physical scale is a useful screening test for mild depression associated with childcare in Japanese child-rearing women.

Introduction: Maternal depression is one of the important problems of postpartum women. For its early detection and appropriate treatment, it is necessary to identify women at high risk for depression quickly and easily. Materials and methods: A simple screening scale for depression from physical aspects, the multidimensional physical scale (MDPS), which is a 17-item, self-report, three-step scale (0, 1, 2) according to the theory of Kampo medicine, was developed. The aim of the present study was to develop (n = 785) and validate (n = 350) the MDPS that was designed to rate the risk of depression. The Beck Depression Inventory-Second Edition was used for determination of depression. In the development cohort, the final model was determined using multi-regression logistic analysis. Results: The components of the MDPS for mothers (MDPS-M) were developed, containing the total score of MDPS (0-34 points) and resumption of menstruation or not (-3, 0 points). Receiver-operating characteristic curve analysis of the MDPS-M (-3 to 34) for identifying a high risk of depression showed moderately good discrimination [area under the curve (AUC) = 0.74, 95% confidence interval (CI): 0.70-0.78]. At the cutoff value of MDPS-M (9/10), its sensitivity, specificity, positive predictive value, and negative predictive value were 84.9, 45.7, 36.7, and 89.2%, respectively. External validation of the MDPS-M showed moderately good discrimination (AUC = 0.74, 95% CI: 0.68-0.79) using the same analysis as the development cohort. Conclusion: These results indicate that the MDPS-M is a useful, simple, clinical scale for early identification of mothers at high risk of depression in primary care.

Development of the paternal brain in expectant fathers during early pregnancy.

The human parenting brain network mediates caregiving behaviors. When exposed to the stimuli of their infants, compared with non-parents, both fathers and mothers exhibit distinct patterns of neural activation. As human males, relative to females, do not undergo robust physiological changes during pregnancy, when and how the paternal brain networks begin to form remains unclear. Thus, using functional MRI, we examined brain activation in response to infant-interaction videos in two groups, childless males and first-time expectant fathers during their partners' early pregnancy before remarkable changes in their partners' appearances commenced. Multivoxel pattern analysis revealed that expectant fathers' left anterior insula and inferior frontal gyrus showed incipient changes in response to parenthood during early pregnancy. Furthermore, these changes were associated with several paternal traits, such as a negative image toward parenting. Such external factors might influence the paternal brain's development during early pregnancy.

Breastfeeding dynamically changes endogenous oxytocin levels and emotion recognition in mothers.

Breastfeeding behaviours can significantly change mothers' physiological and psychological states. The hormone oxytocin may mediate breastfeeding and mothers' emotion recognition. This study examined the effects of endogenous oxytocin fluctuation via breastfeeding on emotion recognition in 51 primiparous mothers. Saliva oxytocin was assessed before and after the manipulation (breastfeeding or holding an infant), and emotion recognition tasks were conducted. Among mothers who breastfed daily, mothers with more increased levels of oxytocin after breastfeeding showed more reduced negative recognition and enhanced positive recognition of adult facial expressions. These oxytocin functions accompanying breastfeeding may support continued nurturing behaviours and also affect the general social cognition of other adults beyond any specific effect on infants.

Maternal nurturing experience affects the perception and recognition of adult and infant facial expressions.

The perception and recognition of facial expressions are crucial for parenting. This study investigated whether and how maternal nurturing experience and trait anxiety influence the perception and recognition of infant and adult facial expressions. This was assessed by comparing the performance of primiparous mothers (n = 25) and non-mothers (n = 28) on an emotional face perception task. Trait anxiety was measured using the Japanese version of the State-Trait Anxiety Inventory (STAI). We found that mothers had higher recognition accuracy for facial expressions, but only of adults, not infants. Moreover, as trait anxiety increased, so did mothers' sensitivity in perceiving facial expressions of both infants and adults. These findings suggest that maternal nurturing experience does enhance the recognition of adult emotional expressions, and an optimal level of maternal trait anxiety may enhance mothers' sensitivity toward infants' and adults' emotional signals.