International Society of Sports Nutrition Position Stand: Probiotics.

Position statement: The International Society of Sports Nutrition (ISSN) provides an objective and critical review of the mechanisms and use of probiotic supplementation to optimize the health, performance, and recovery of athletes. Based on the current available literature, the conclusions of the ISSN are as follows: 1)Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host (FAO/WHO).2)Probiotic administration has been linked to a multitude of health benefits, with gut and immune health being the most researched applications.3)Despite the existence of shared, core mechanisms for probiotic function, health benefits of probiotics are strain- and dose-dependent.4)Athletes have varying gut microbiota compositions that appear to reflect the activity level of the host in comparison to sedentary people, with the differences linked primarily to the volume of exercise and amount of protein consumption. Whether differences in gut microbiota composition affect probiotic efficacy is unknown.5)The main function of the gut is to digest food and absorb nutrients. In athletic populations, certain probiotics strains can increase absorption of key nutrients such as amino acids from protein, and affect the pharmacology and physiological properties of multiple food components.6)Immune depression in athletes worsens with excessive training load, psychological stress, disturbed sleep, and environmental extremes, all of which can contribute to an increased risk of respiratory tract infections. In certain situations, including exposure to crowds, foreign travel and poor hygiene at home, and training or competition venues, athletes' exposure to pathogens may be elevated leading to increased rates of infections. Approximately 70% of the immune system is located in the gut and probiotic supplementation has been shown to promote a healthy immune response. In an athletic population, specific probiotic strains can reduce the number of episodes, severity and duration of upper respiratory tract infections.7)Intense, prolonged exercise, especially in the heat, has been shown to increase gut permeability which potentially can result in systemic toxemia. Specific probiotic strains can improve the integrity of the gut-barrier function in athletes.8)Administration of selected anti-inflammatory probiotic strains have been linked to improved recovery from muscle-damaging exercise.9)The minimal effective dose and method of administration (potency per serving, single vs. split dose, delivery form) of a specific probiotic strain depends on validation studies for this particular strain. Products that contain probiotics must include the genus, species, and strain of each live microorganism on its label as well as the total estimated quantity of each probiotic strain at the end of the product's shelf life, as measured by colony forming units (CFU) or live cells.10)Preclinical and early human research has shown potential probiotic benefits relevant to an athletic population that include improved body composition and lean body mass, normalizing age-related declines in testosterone levels, reductions in cortisol levels indicating improved responses to a physical or mental stressor, reduction of exercise-induced lactate, and increased neurotransmitter synthesis, cognition and mood. However, these potential benefits require validation in more rigorous human studies and in an athletic population

Relationships between perceived parental involvement in homework, student homework behaviors, and academic achievement: differences among elementary, junior high, and high school students

This study aims to produce a deeper understanding of the relationship between perceived parental homework involvement (i.e., parental homework control and parental homework support), student homework behaviors (i.e., time spend on homework completion, time management, and amount of homework completed), and student academic achievement. Using Mplus5.1, a structural equation model was fit for 1683 students at different stages of schooling (i.e., elementary school -aEuro parts per thousand 5th and 6th grades; junior high school -aEuro parts per thousand 7th and 8th grades; and high school -aEuro parts per thousand 9th and 10th grades). The data showed that student homework behaviors, perceived parental homework involvement, and academic achievement are significantly related. However, results vary depending on the students' grade level: (a) in junior high and high school, perceived parental homework involvement is related to students' homework behaviors, but not in elementary school; and (b) although students' homework behaviors are related to academic achievement at each school level, the direction and magnitude of the relationships vary. Specifically, the relationship between perceived parental homework involvement and academic achievement is stronger in junior high and high school than in elementary school; and student homework behaviors mediate the association between perceived parental homework involvement (control and support) and academic achievement only in junior high and high school.This manuscript was completed with the help of funding from Ministry of Science and Innovation (EDU2010-16231 and PSI2011-23395) and the Ministry of Economy and Finance (BES-2011-043927) of Spain.info:eu-repo/semantics/publishedVersio

Does teacher homework feedback matter to 6th graders' school engagement?: a mixed methods study

The effectiveness of homework on improving student academic achievement depends on several factors; for example, feedback provided by the teacher (i.e. grading) and student engagement are important moderators in this process. However, the relationships between the types of homework feedback commonly used by teachers and student school engagement have not yet been examined. Anchored in the Self-Determination Theory, this mixed methods sequential explanatory study investigated how five types of teacher homework feedback predict three dimensions of students' school engagement. The participants included 6th graders (N = 4288) and their mathematics teachers (N = 170). For this investigation, a quantitative phase was run, followed by a qualitative phase. The quantitative data were analyzed using multivariate multilevel regression models. The quantitative data showed positive relationships between five types of feedback and school engagement, albeit with different results at student and class levels. The findings showed small effect sizes. The qualitative data, based on a purposeful sampling, provided further insights regarding the low effect sizes that were found. Data were analyzed using thematic analysis. Four themes were identified as follows: homework at home and/or at the study center, perceived homework feedback types, school engagement, and school disaffection. Both data sets indicated directions to strengthen the benefits of homework feedback and to maximize students' learning. This research paper discusses practical implications as well as future research directions.This study was conducted at Psychology Research Centre (UID/PSI/01662/2013), University of Minho, and supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Science, Technology and Higher Education through national funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653). The first author was supported by a PhD fellowship from the Portuguese Foundation for Science and Technology (FCT – SFRH/BD/95341/2013)

Temporal trends in between and within‐country inequalities in caesarean delivery in low‐ and middle‐income countries: a Bayesian analysis

Objective: To provide updated information about between-country variations, temporal trends and changes in inequalities within countries in caesarean delivery (CD) rates. Design: Cross-sectional study of Demographic and Health Survey (DHS) during 1990–2018. Setting: 74 low- and middle-income countries (LMICs). Population: Women 15–49 years of age who had live births in the last 3 years. Methods: Bayesian linear regression analysis was performed and absolute differences were calculated. Main outcome measure: Population-level CD by countries and sociodemographic characteristics of mothers over time. Results: CD rates, based on the latest DHS rounds, varied substantially between the study countries, from 1.5% (95% CI 1.1–1.9%) in Madagascar to 58.9% (95% CI 56.0–61.6%) in the Dominican Republic. Of 62 LMICs with at least two surveys, 57 countries showed a rise in CD during 1990–2018, with the greatest increase in Sierra Leone (19.3%). Large variations in CD rates were observed across mother's wealth, residence, education and age, with a higher rate of CD by the richest and urban mothers. These inequalities have widened in many countries. Stratified analyses suggest greater provisioning of CD by the richest mothers in private facilities and poorest mothers in public facilities

The combined association of adherence to Mediterranean diet, muscular and cardiorespiratory fitness on low-grade inflammation in adolescents: a pooled analysis

Purpose: Low-grade inflammation leads to several metabolic disorders, and adherence to a Mediterranean diet (MedDiet), cardiorespiratory fitness (CRF), and muscular fitness (MF) has been considered important markers of metabolic healthy in youth. We investigated the combined association of adherence to Mediterranean diet, and muscular and cardiorespiratory fitness on high-sensitivity C-reactive protein (hs-CRP) in adolescents. Methods: This is a cross-sectional analysis with 1462 adolescents (625 girls) aged 9-18 years from Colombia and Portugal. MedDiet was assessed by Kidmed questionnaire. Shuttle run test was used to assess CRF. MF was assessed by the standing long-jump and handgrip tests. High-sensitivity assays were used to obtain the hs-CRP level.Results Logistic regression shows that subjects with a low adherence to MedDiet and LowMF/LowCRF had a similar odds (OR = 2.3; 95% CI 1.2-4.0) as those with an optimal adherence to MedDiet and LowMF/LowCRF (OR = 2.3; 95% CI 1.2-5.0) of expressing high inflammatory profile when compared to those with an optimal adherence to MedDiet and HighMF/HighCRF. In addition, ANCOVA showed that subjects classified as high adherence to MedDiet and HighMF/HighCRF had, on average, the lowest levels of hs-CRP (F-(7,F-1454) = 2.051 p = 0.04). Conclusion: The combination of optimal levels of CRF and MF and adherence to MedDiet is associated with lower hs-CRP. However, high MF and CRF seems to counteract the deleterious effect of having a low adherence to the MedDiet on hs-CRP levels.The Research Centre on Physical Activity Health and Leisure (CIAFEL) is supported by UID/DTP/00617/2013 (FCT). The FUPRECOL Study was carried out with the financial support of Instituto Colombiano para el Desarrollo de la Ciencia y la Tecnologia "Francisco Jose de Caldas" COLCIENCIAS (Contract No 671-2014 Code 122265743978). The authors are grateful to the Bogota District Education Secretary for the data used in this study. The authors also thank the participating Bogota District students, teachers, schools, and staff