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Ribosomal DNA (rDNA) copies exist across multiple chromosomes, and interindividual variation in copy number is speculated to influence the hypertrophic response to resistance training. Thus, we examined if rDNA copy number was associated with resistance training-induced skeletal muscle hypertrophy. Participants (n = 53 male, 21 ± 1 yr old; n = 29 female, 21 ± 2 yr old) performed 10–12 wk of full-body resistance training. Hypertrophy outcomes were determined, as was relative rDNA copy number from preintervention vastus lateralis (VL) biopsies. Pre- and postintervention VL biopsy total RNA was assayed in all participants, and mRNA/rRNA markers of ribosome content and biogenesis were also assayed in the 29 female participants before training, 24 h following training bout 1, and in the basal state after 10 wk of training. Across all participants, no significant associations were evident between relative rDNA copy number and training-induced changes in whole body lean mass (r = −0.034, P = 0.764), vastus lateralis thickness (r = 0.093, P = 0.408), mean myofiber cross-sectional area (r = −0.128, P = 0.259), or changes in muscle RNA concentrations (r = 0.026, P = 0.818), and these trends were similar when examining each gender. However, all Pol-I regulon mRNAs as well as 45S pre-rRNA, 28S rRNA, and 18S rRNA increased 24 h following the first training bout in female participants. Follow-up studies using LHCN-M2 myotubes demonstrated that a reduction in relative rDNA copy number induced by bisphenol A did not significantly affect insulin-like-growth factor-induced myotube hypertrophy. These findings suggest that relative rDNA copy number is not associated with myofiber hypertrophy. NEW & NOTEWORTHY: We examined ribosomal DNA (rDNA) copy numbers in men and women who resistance trained for 10–12 wk and found no significant associations with skeletal muscle hypertrophy outcomes. These data, along with in vitro data in immortalized human myotubes whereby rDNA copy number was reduced, provide strong evidence that relative rDNA copy number is not associated with anabolism. [ABSTRACT FROM AUTHOR]

Baccalaureate nursing students are at increased risk for anxiety and related mood disorders. We conducted a cross-sectional study to explore the relationships among anxiety symptoms measured by the Generalized Anxiety Disorder (GAD-7) questionnaire and lifestyle behaviors including habitual diet, sleep quality (Pittsburg Sleep Quality Index [PSQI]), and physical activity. Descriptive statistics were obtained for sample characteristics, and Pearson correlations and backward stepwise linear regression explored relationships between the GAD-7 scores, the Multidimensional Assessment of Interoceptive Awareness, version 2 (MAIA-2) subscales, and other variables. Sixty-eight students completed the survey, with 38% having moderate-to-severe anxiety. On average, respondents had moderate diet quality (Healthy Eating Index median 60/100 [range 51–75]), had high sleep quality (PSQI median 7/21 [range 4–10]), and were highly active, with a median of 43 (range 24–78) weekly metabolic equivalent (MET) hours. Sixty-seven out of 68 respondents indicated a willingness to change lifestyle behaviors; the most prevalent time-related factors were school and social commitments, with stress and financial constraints being reported among half or more of respondents. Regression analysis determined that PSQI (β = 0.446) and the MAIA-2 Not-Worrying subscale (β = −0.366) were significant (p < 0.001 for both) predictors of anxiety severity. These results indicate that mindfulness and sleep hygiene may be the most actionable foci for interventions to reduce anxiety in baccalaureate nursing students. This study was not registered as a clinical trial. [ABSTRACT FROM AUTHOR]

To investigate the gut-brain axis, we explored the relationships among mood disturbance (MD), diet quality (DQ), and fecal microbiota in free-living adults. A cross-sectional analysis was conducted with data from 75 healthy adults enrolled in two studies. Anthropometrics, 16s rRNA gene sequencing of fecal microbes, DQ as assessed by Healthy Eating Index-2015 (HEI), and MD determined by Profile of Mood States (POMS) were included. Alpha-diversity and DQ differences were explored between low (n = 37) and high MD (n = 38) groups. Spearman correlations were used to investigate relationships between alpha-diversity, DQ, and POMS subscales. Moderation analysis explored the effect of HEI score on the relationship between MD and alpha-diversity. Participants were mostly white (67%), 54.5 years old (±11.8), and overweight (28.5 ± 6.5 kg/m2). Shannon and Simpson indices indicate higher alpha-diversity in participants with low MD compared to high MD (p = 0.004 and p = 0.008, respectively). Simpson and Shannon indices were correlated with subscale of anger (rho = −0.303, p = 0.011; rho = −0.265, p = 0.027, respectively)and total MD (rho = −0.404, p = 0.001; rho = −0.357, p = 0.002, respectively). Refined grains were associated with fatigue and tension subscales (rho = 0.428, p < 0.001; rho = 0.302, p = 0.014, respectively). DQ did not significantly moderate the relationship between alpha-diversity and mood disturbance (F(7, 53) = 2.00, p = 0.072, R2 = 0.209). Shannon index was a significant predictor of MD (b = −4.39, t(53) = −2.55, p = 0.014), but total HEI score and the interaction (Shannon index*HEI score) were not significant. Greater bacterial diversity was associated with lower MD, and DQ was associated with various mood state subscales in this sample of adults. [ABSTRACT FROM AUTHOR]

Objective: Altering the gut microflora may produce health benefits in individuals suffering from mood disorders. The purpose of this review was to evaluate the efficacy of probiotics, prebiotics, or synbiotics as a potential treatment for symptoms of depression, anxiety, and stress (as psychobiotics). Methods: Google Scholar, PubMed, PsychINFO, and Web of Science were utilized to identify and evaluate studies through October 31, 2019. Studies were included if subjects were evaluated for altered mood or stress levels at start of the study and consumed probiotics, prebiotics, and/or synbiotics for intervention. Results: Search results yielded 142 articles, while only 12 studies met all inclusion criteria. Nine of the 12 studies identified evaluated the efficacy of various probiotic strains, while only two evaluated synbiotics and one evaluated prebiotics. Six out of 12 studies found probiotics to reduce depression, while two studies found probiotics to reduce anxiety. Discussion: Translational research in this field is limited and further investigation of the efficacy of psychobiotics in mood disorders is warranted. [ABSTRACT FROM AUTHOR]

Breast cancer is a hormonally-driven cancer, and various dietary factors are associated with estrogen metabolism, including dietary fiber. Several studies report associations between dietary fiber and breast cancer; however, research on whether fiber influences circulating estrogens through the gut microbiota is rare. The objective of this cross-sectional study among 29 newly-diagnosed (stage 0-II), post-menopausal breast cancer patients is to examine associations between dietary fiber and the gut microbiota that are linked with β-glucuronidase activity, and purportedly increase circulating estrogens. Spearman's and partial correlations controlling for body mass index and age were performed using dietary recall data, Illumina MiSeq generated microbiota relative abundance, and HPLC-mass spectrometry-derived estradiol and estrone levels. Major findings are: (1) total dietary fiber is inversely associated with Clostridium hathewayi (r= −0.419; p = 0.024); (2) soluble fiber is inversely associated with Clostridium (r=-0.11; p = 0.02); (3) insoluble fiber is positively associated with Bacteroides uniformis sp. (r = 0.382; p = 0.041); and (4) serum estradiol and estrone levels are not correlated with species/genera or dietary fiber, though there is a trend toward an inverse association between soluble fiber and estradiol levels (r= −0.30; p = 0.12). More studies are needed to understand the complex interaction between dietary fiber, intestinal microbiota, and hormonal levels in older females. [ABSTRACT FROM AUTHOR]