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The microbiota modulates gut immune homeostasis. Bacteria influence the development and function of host immune cells, including T helper cells expressing interleukin-17A (TH17 cells). We previously reported that the bile acid metabolite 3-oxolithocholic acid (3-oxoLCA) inhibits TH17 cell differentiation1. Although it was suggested that gut-residing bacteria produce 3-oxoLCA, the identity of such bacteria was unknown, and it was unclear whether 3-oxoLCA and other immunomodulatory bile acids are associated with inflammatory pathologies in humans. Here we identify human gut bacteria and corresponding enzymes that convert the secondary bile acid lithocholic acid into 3-oxoLCA as well as the abundant gut metabolite isolithocholic acid (isoLCA). Similar to 3-oxoLCA, isoLCA suppressed TH17 cell differentiation by inhibiting retinoic acid receptor-related orphan nuclear receptor-γt, a key TH17-cell-promoting transcription factor. The levels of both 3-oxoLCA and isoLCA and the 3α-hydroxysteroid dehydrogenase genes that are required for their biosynthesis were significantly reduced in patients with inflammatory bowel disease. Moreover, the levels of these bile acids were inversely correlated with the expression of TH17-cell-associated genes. Overall, our data suggest that bacterially produced bile acids inhibit TH17 cell function, an activity that may be relevant to the pathophysiology of inflammatory disorders such as inflammatory bowel disease.

Introduction: Based on the Just World Theory (JWT) and Worldview Verification Theory (WVT), we conducted two studies to investigate whether a belief in a just world for the self (BJW-self) moderates the relationship between perceived discrimination against older adults (ageism) and self-esteem in a sample of South Koreans older adults. Methods: In Study 1, we collected survey data from 304 South Koreans aged 65 and older using the scales of perceived ageism, BJW-self, and self-esteem. In Study 2, we randomly assigned 140 South Koreans aged 65 and older to read one of two articles: one describing ageism as pervasive or one describing ageism as rare. Results: Study 1 revealed that perceived ageism negatively correlated with self-esteem at low levels of BJW-self than at high levels of BJW-self. In Study 2, older adults who were told that ageism is pervasive had lower self-esteem than those who were told that ageism is rare, but this difference was greater for those who rejected BJW-self than for those who endorsed BJW-self. Discussion: The results support the notion of the JWT that BJW-self mitigates the deleterious effects of perceived ageism on self-esteem. [ABSTRACT FROM AUTHOR]

This study estimates the long‐term effect of parenthood on labor market outcomes and explores the variations within this effect by gender and education. We use the event study method to track changes in a range of labor market outcomes from 3 years before to 8 years after the first birth, with a sample of 556 married women and 528 married men from the Korea Labor and Income Panel Study (KLIPS). We find that women experience an immediate drop in wages following birth, whereas men experience continuous wage growth even before birth. The decline in women's wages arises largely from their withdrawal from the labor market, while the increase in men's wages could be explained by a positive selection bias among fathers. In addition, mothers' wage trajectories do not vary significantly by education level, whereas other labor market outcomes show discernible trends. These patterns are the opposite of those observed for men. The findings indicate that severe gender inequality in the Korean labor market lowers the wages of mothers, regardless of their education, while the wages of fathers are more likely to be affected by education. Based on the findings, we make policy suggestions for improving the work‐family balance for all genders. [ABSTRACT FROM AUTHOR]

Aim: Periodontitis is a potential risk factor for preterm birth (PTB) in women; however, the causal relationship or the exact mechanism remain unknown. This study aimed to compare the oral microbiome features of mothers with full‐term birth (FTB) with those who had preterm delivery. Methods: This study prospectively enrolled 60 women (30 mothers with PTB and 30 mothers with FTB), and subgingival plaque samples were collected and analysed by metagenomic 16S rDNA sequencing. Clinical measurements, including periodontal probing depth, clinical attachment level, modified gingival index (mGI) and plaque index, were performed to determine the periodontal state of the participants. Medical and obstetric data were collected as well. Results: Among the periodontal measurements, mGI score, reflecting the level of gingival inflammation, exhibited a statistically significant association with PTB (adjusted odds ratio 2.705, 95% confidence interval 1.074–6.811, p =.035). When subgroup analysis was conducted based on mean mGI scores (mGI ≥ 2, high inflammation [HI] versus mGI < 2, low inflammation [LI]), microbiome analysis revealed clear distinctions in microbial compositions between PTB and FTB mothers in both the HI and LI groups. Especially in the HI group, alpha diversity exhibited a decreasing trend in PTB mothers compared to FTB mothers. Beta diversity also revealed significant differences between the two groups. In Linear Discriminant Analysis Effect Size analysis, certain anaerobic taxa, including the genera Spirochaetes, Treponema and Porphyromonas, were relatively abundant in the FTB/HI group, whereas the PTB/HI group showed a high abundance of the order Actinomycetales. Network analysis showed that the FTB/HI had relatively stronger connectivity in microbial composition than the PTB/HI group. Dysbiosis ratio of plaque microbiome, in terms of periodontitis, was significantly lower in PTB/HI group compared to FTB/HI group. Conclusion: The compositions of maternal subgingival microbiomes differed between PTB and FTB mothers in both the high and low levels of gingival inflammation groups. In the presence of high level of gingival inflammation, dysbiosis in plaque microbiome, in terms of periodontitis, was decreased in PTB mothers compared to FTB mothers. [ABSTRACT FROM AUTHOR]

This qualitative study explores the stressful experiences faced by asexual individuals in South Korea. We conducted in-depth interviews with 12 South Korean adults who identified as asexual and analysed their data using consensus qualitative research. The analyses revealed 20 categories across five domains, including difficulties in defining and articulating asexual identity due to a lack of language and representation, facing denial and invalidation, navigating ambivalent experiences of invisibility, combating misconceptions, and encountering difficulties in connecting with asexual individuals and other members of the queer community. The study identified several stressors reported by South Korean asexual individuals, such as the dearth of language and representation regarding asexuality, lack of access to asexual networks, misconception that experiencing little or no sexual attraction is caused by a lack of love, casual use of the term ‘asexual’, and fear of increasing invisibility by concealing one’s asexual identity. Although these stressors have not been widely documented in other contexts, further research is needed to determine whether they are unique to the South Korean context. These findings highlight the need for greater awareness and understanding of asexuality in South Korea to promote the well-being and inclusion of asexual individuals. [ABSTRACT FROM AUTHOR]

The present study examined roles that perceived English fluency and sociocultural adaptation difficulty play in predicting self-efficacy beliefs for teaching in a sample of 119 international teaching assistants (ITAs) from East Asian countries of China, Japan, Korea and Taiwan. Results showed that a positive relationship between perceived English fluency and teaching self-efficacy was not apparent until the moderating influence of sociocultural adaptation difficulty was examined. More specifically, at high levels of adaptation difficulty, positive relations between English fluency and teaching self-efficacy were found; however, as sociocultural adaptation difficulty decreased, the effect of perceived fluency in English on efficacy decreased. Implications for ITA training as well as limitations of the study were discussed. (Contains 1 figure and 2 tables.)

This study explored the effects of ethnic/racial matching on psychotherapy outcomes via the number of counseling sessions attended by clients, using clinical data collected from a university's counseling center. A total sample of 644 clients (193 men, 448 women) was selected and the ethnic/racial distribution of the sample comprised 499 White/European American (77.5%), 81 African American (12.6%), 33 Asian American (5.1%), and 31 Hispanic clients (4.8%). As a result of a multilevel mediation analysis, it was found that the clients working with counselors of matching ethnicity/race attended more number of counseling sessions than those with counselors of different ethnicity/race. Moreover, the ethnic/racial matching between clients and counselors led to a higher improvement of global assessment of function (GAF). The analysis also revealed that the client-counselor ethic/racial matching showed significant, direct effects on the improvement of GAF. The effects of ethnic/racial matching on the number of counseling sessions and GAF improvement significantly differed at the counselor-level. Clinical implications to multicultural counseling and training are provided.

This study examined how child problem behaviour could be related to maternal Hwa-Byung (HB; Korean culture syndrome, meaning "anger illness") among Korean mothers of children with developmental disabilities. Acceptance of disabilities and parenting stress were tested as mediators for the relationship between child problem behaviour and maternal HB. The results indicated that child problem behaviour alone (e.g. self-injurious and aggressive behaviours, yelling/screaming, and crying) were not related to maternal HB. Instead, child problem behaviour was not directly associated with maternal HB, but indirectly related to maternal HB through decreased acceptance of disability and increased parenting stress. The findings of the study support the importance of Acceptance and Commitment therapy and parenting stress intervention to prevent and treat HB among Korean mothers of children with developmental disabilities.

Efforts are underway for development of crops with improved levels of provitamin A carotenoids to help combat dietary vitamin A deficiency. As a global staple crop with considerable variation in kernel carotenoid composition, maize (Zea mays L.) could have a widespread impact. We performed a genome-wide association study (GWAS) of quantified seed carotenoids across a panel of maize inbreds ranging from light yellow to dark orange in grain color to identify some of the key genes controlling maize grain carotenoid composition. Significant associations at the genome-wide level were detected within the coding regions of zep1 and lut1, carotenoid biosynthetic genes not previously shown to impact grain carotenoid composition in association studies, as well as within previously associated lcyE and crtRB1 genes. We leveraged existing biochemical and genomic information to identify 58 a priori candidate genes relevant to the biosynthesis and retention of carotenoids in maize to test in a pathway-level analysis. This revealed dxs2 and lut5, genes not previously associated with kernel carotenoids. In genomic prediction models, use of markers that targeted a small set of quantitative trait loci associated with carotenoid levels in prior linkage studies were as effective as genome-wide markers for predicting carotenoid traits. Based on GWAS, pathway-level analysis, and genomic prediction studies, we outline a flexible strategy involving use of a small number of genes that can be selected for rapid conversion of elite white grain germplasm, with minimal amounts of carotenoids, to orange grain versions containing high levels of provitamin A.