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The translational power of human microbiome studies is limited by high interindividual variation. We describe a dimensionality reduction tool, compositional tensor factorization (CTF), that incorporates information from the same host across multiple samples to reveal patterns driving differences in microbial composition across phenotypes. CTF identifies robust patterns in sparse compositional datasets, allowing for the detection of microbial changes associated with specific phenotypes that are reproducible across datasets.

Aging is often associated with a dysregulation in immune function, particularly in T-cell responses, even in the healthy elderly. Adequate nutrition is important for optimal immune function. The literature on the relation of nutritional status with immune function in the elderly offers mixed findings. Because several nutrients can influence immune response, and there are interactions among nutrients, examining the association of various nutrients measured simultaneously with tests of immune function is important. We examined the association of protein, iron, zinc, vitamin B-12, and folic acid with tests of acquired immunity in healthy older women (76.7 [+ or -] 7.0 y; n = 130). Discriminant analysis was used to identify the predictive subset of nutrients that could correctly classify subjects into the lowest or highest quartiles ([less than or equal to] 25th or >75th percentile) on various immune function tests (T cells and subsets and lymphocyte proliferation in response to culture with mitogens). Protein and iron status variables were identified in the predictive subset for all immune tests; in addition, zinc emerged in the predictive model for T cells and their subsets as well as for the proliferation response to concanavalin A. The probability of correctly classifying women into the lowest or highest quartiles of immune tests by the predictive subset of nutrition variables was high, i.e., 62.8-83.5% for T cells and their subsets, and 79.3-89.7% for the proliferation response to mitogens. In conclusion, protein, iron, and zinc were significant predictors of immune function in older women. Adequate status of these nutrients may help maintain immunity in older adults. KEY WORDS: * immune function * nutrition * leukocyte subsets * lymphocyte proliferation * aging

There are various problems or expenses associated with traditional laboratory tests of iron status, but recent attention focusing on the measurement of serum/plasma transferrin receptors (TfR) has shown merit. TfR can detect mild iron deficiency and distinguish anemia secondary to inflammation. The measurement of sensitivity, specificity and reliability as compared to traditional measure of iron status is assessed.

Objective To determine the day-to-day variation in biochemical measures of iron status in a group of elderly women with rheumatoid arthritis compared with a group of healthy elderly women. Design Venous blood samples were collected from each subject on 3 nonconsecutive days during a 2-week study period; subjects had fasted overnight. Variability in hemoglobin level, hematocrit value, serum iron concentration, total iron-binding capacity, transferrin saturation, serum ferritin concentration, and plasma transferrin receptor level was determined. Subjects Two groups of women, one with rheumatoid arthritis (n=10) and another that was apparently healthy (n=10). Statistical analyses Variance component analysis was used to estimate the biological variation ([[Σ.sup.2].sub.day]) and analytic variation ([[Σ.sup.2].sub.rep]) for each iron index. The coefficient of variation (CV) for each variance component was calculated: coefficient of biological variation = [CV.sub.day], coefficient of analytic variation = [CV.sub.rep], and coefficient of a single future determination = [CV.sub.fd]. Results The [CV.sub.rep] for all iron indexes was smaller than the [CV.sub.day] in both groups. The [CV.sub.day] was considerably higher for serum iron concentration and for transferrin saturation than for the other indexes in both groups (16.6% and 16.6% in healthy subjects and 33.6% and 28.2%, respectively, in subjects with rheumatoid arthritis). The higher [CV.sub.day] for serum iron concentration and transferrin saturation translated into a higher [CV.sub.fd] for these indexes. Because of the higher variance for these two indexes, more sampling days were required for reliable estimates. [CV.sub.day] and [CV.sub.fd] for plasma transferrin receptor level were relatively low. Conclusions These findings corroborate our previous finding that variation of serum ferritin concentration in the elderly is lower than that demonstrated in younger populations. This aging effect persists in the presence of rheumatoid arthritis. Fasting appeared to improve reliability in the determinations for serum iron concentration and transferrin saturation. Variability estimates for the indexes other than serum iron concentration and transferrin saturation were not altered by the inflammation of rheumatoid arthritis. Plasma transferrin receptor level is a reliable index for assessing iron status in populations with rheumatoid arthritis. J Am Diet Assoc. 1996; 96:247-251., Chronic disease and iron deficiency are the most common causes of anemia in the elderly (1). Clinicians rely on biochemical laboratory tests for assessing iron status to assist them in [...]

Abstract Background The prevalence of overweight in children and adolescents is high and overweight is associated with poor health outcomes over short- and long-term. Lifestyle factors can interact to influence overweight. Comprehensive studies linking overweight concomitantly with several demographic and potentially-modifiable lifestyle factors and health-risk behaviours are limited in adolescents - an age-group characterized by changes in lifestyle behaviours and high prevalence of overweight. Thus, the objective of the current study was to examine the association of overweight with several socio-demographic and lifestyle variables simultaneously in a representative sample of adolescents. Methods A nationally representative sample of 11-15 year-olds (n = 7154) in France participated as part of the WHO-Collaborative Health Behaviour in School-aged Children (HBSC) study. Students reported data on their age, height, weight, socio-demographic variables, lifestyle factors including nutrition practices, physical activity at two levels of intensity (moderate and vigorous), sedentary behaviours, as well as smoking and alcohol consumption patterns using standardized HBSC protocols. Overweight (including obesity) was defined using the IOTF reference. The multivariate association of overweight with several socio-demographic and lifestyle factors was examined with logistic regression models. Results The adjusted odds ratios for the association with overweight were: 1.80 (95% CI: 1.37-2.36) for low family affluence; 0.73 (0.60-0.88) for eating breakfast daily; 0.69 (0.56-0.84) for moderate to vigorous physical activity (MVPA); and 0.71 (0.59-0.86) for vigorous physical activity (VPA). Significant interactions between age and gender as well as television (TV) viewing and gender were noted: for boys, overweight was not associated with age or TV viewing; in contrast, for girls overweight correlated negatively with age and positively with TV viewing. Fruit and vegetable intake, computer and video-games use, smoking and alcohol consumption were not associated with overweight. Conclusions In multivariate model, family affluence, breakfast consumption and moderate to vigorous as well as vigorous physical activity were negatively associated with overweight. These findings extend previous research to a setting where multiple risk and protective factors were simultaneously examined and highlight the importance of multi-faceted approaches promoting physical activity and healthy food choices such as breakfast consumption for overweight prevention in adolescents.

Abstract Background Parents have significant influence on behaviors and perceptions surrounding eating, body image and weight in adolescents. The aim of this study was to examine the prevalence of body weight dissatisfaction, difficulty in communication with the parents and the relationship between communication with parents and adolescents' dissatisfaction with their body weight (dieting or perceived need to diet). Methods Survey data were collected from adolescents in 24 countries and regions in Europe, Canada, and the USA who participated in the cross-sectional 2001/2002 Health Behaviour of School-Aged Children (HBSC) study. The association between communication with parents and body weight dissatisfaction was examined using binary logistic regression analysis. Results Body weight dissatisfaction was highly prevalent and more common among girls than boys, among overweight than non-overweight, and among older adolescents than younger adolescents. Difficulty in talking to father was more common than difficulty in talking to mother in all countries and it was greater among girls than among boys and increased with age. Difficulties in talking to father were associated with weight dissatisfaction among both boys and girls in most countries. Difficulties in talking to mother were rarely associated with body weight dissatisfaction among boys while among girls this association was found in most countries. Conclusion The findings suggest that enhanced parent communication might contribute in most countries to less body dissatisfaction in girls and better communication with the father can help avoiding body weight dissatisfaction in boys. Professionals working with adolescents and their families should help adolescents to have a healthy weight and positive body image and promote effective parent – adolescent communication.

Despite advances in scientific knowledge regarding multiple etiology, treatment, and potential strategies for combating iron deficiency and deficiencies of other micronutrients, iron deficiency anemia, vitamin A deficiency, and iodine deficiency remain significant public health challenges for growing children and adolescents. The short-term efficient supplementation approach, although technically feasible, has not been successful due to problems with delivery and compliance. Evidence is building that preventive supplementation coupled with nutrition education may be a more effective strategy associated with better compliance and improvement in iron status. Long-term, effective approaches include fortification, dietary modification, public health and disease control measures, and income generation programs. Food fortification can be a cost-effective intervention strategy if technologically feasible, nutritionally sound, culturally acceptable and economically viable food vehicle(s) and fortificant(s) can be identifed. Foods such as wheat, rice, and salt are commonly consumed in India; research is underway to evaluate various fortificants for these foods. Doubly fortified salt with iodine and iron may be particularly promising in the Indian situation as it is affordable, culturally acceptable, and may enhance iron absorption from Indian dietaries containing inhibitors of iron absorption. Feasibility studies are underway to evalute the stability and storage issues as weft as bioavailability of fortificant iron. Dietary modification involves increased iron intake, by increasing total food intake and consumption of locally available iron-rich foods, and dietary practices favoring iron absorption. Blood loss associated with worm infestation can be controlled by periodic deworming and reducing reinfestation. Coordinating these major intervention approaches by building partnerships between the community, existing nutrition and health programs, government, industry, and academic institutions is critical for success of these programs. Nutrition education must be integral to all of these strategies discusssed. Primary health care system and school infrastructure and staff, along with school children and community members, can be powerful resources for addressing malnutrition in children and adolescents.