Luciana D. Folchetti

Gut microbiota interactions with the immunomodulatory role of vitamin D in normal individuals

BACKGROUND Due to immunomodulatory properties, vitamin D status has been implicated in several diseases beyond the skeletal disorders. There is evidence that its deficiency deteriorates the gut barrier favoring translocation of endotoxins into the circulation and systemic inflammation. Few studies investigated whether the relationship between vitamin D status and metabolic disorders would be mediated by the gut microbiota composition. OBJECTIVE We examined the association between vitamin D intake and circulating levels of 25(OH)D with gut microbiota composition, inflammatory markers and biochemical profile in healthy individuals. METHODS In this cross-sectional analysis, 150 young healthy adults were stratified into tertiles of intake and concentrations of vitamin D and their clinical and inflammatory profiles were compared. The DESeq2 was used for comparisons of microbiota composition and the log2 fold changes (log2FC) represented the comparison against the reference level. The association between 25(OH)D and fecal microbiota (16S rRNA sequencing, V4 region) was tested by multiple linear regression. RESULTS Vitamin D intake was associated with its concentration (r=0.220, p=0.008). There were no significant differences in clinical and inflammatory variables across tertiles of intake. However, lipopolysaccharides increased with the reduction of 25(OH)D (p-trend <0.05). Prevotella was more abundant (log2FC 1.67, p<0.01), while Haemophilus and Veillonella were less abundant (log2FC -2.92 and -1.46, p<0.01, respectively) in the subset with the highest vitamin D intake (reference) than that observed in the other subset (first plus second tertiles). PCR (r=-0.170, p=0.039), E-selectin (r=-0.220, p=0.007) and abundances of Coprococcus (r=-0.215, p=0.008) and Bifdobacterium (r=-0.269, p=0.001) were inversely correlated with 25(OH)D. After adjusting for age, sex, season and BMI, 25(OH)D maintained inversely associated with Coprococcus (β=-9.414, p=0.045) and Bifdobacterium (β=-1.881, p=0.051), but significance disappeared following the addition of inflammatory markers in the regression models. CONCLUSION The role of vitamin D in the maintenance of immune homeostasis seems to occur in part by interacting with the gut microbiota. The attenuation of association of bacterial genera by inflammatory markers suggests that inflammation participate in part in the relationship between the gut microbiota and vitamin D concentration. Studies with appropriate design are necessary to address hypothesis raised in the current study.

Assessment of leisure-time physical activity for the prediction of inflammatory status and cardiometabolic profile

OBJECTIVES Associations of leisure-time physical activity (LTPA), commuting and total physical activity with inflammatory markers, insulin resistance and metabolic profile in individuals at high cardiometabolic risk were investigated. DESIGN This was a cross-sectional study. METHODS A total of 193 prediabetic adults were compared according to physical activity levels measured by the international physical activity questionnaire; p for trend and logistic regression was employed. RESULTS The most active subset showed lower BMI and abdominal circumference, reaching significance only for LTPA (p for trend=0.02). Lipid profile improved with increased physical activity levels. Interleukin-6 decreased with increased total physical activity and LTPA (p for trend=0.02 and 0.03, respectively), while adiponectin increased in more active subsets for LTPA (p for trend=0.03). Elevation in adjusted OR for hypercholesterolemia was significant for lower LTPA durations (p for trend=0.04). High apolipoprotein B/apolipoprotein A ratio was inversely associated with LTPA, commuting and total physical activity. Increase in adjusted OR for insulin resistance was found from the highest to the lowest category of LTPA (p for trend=0.04) but significance disappeared after adjustments for BMI and energy intake. No association of increased C-reactive protein with physical activity domains was observed. CONCLUSIONS In general, the associations of LTPA, but not commuting or total physical activity, with markers of cardiometabolic risk reinforces the importance of initiatives to increase this domain in programs for the prevention of lifestyle-related diseases.

Análise de diferentes medidas antropométricas na identificação de síndrome metabólica, com ou sem alteração do metabolismo glicídico

OBJECTIVE: This study compared anthropometric measurements and insulin resistance indexes of individuals with or without metabolic syndrome (MS), stratified by the presence of glycemic abnormalities. SUBJECTS AND METHODS: 454 individuals (66% women, 54% Caucasians) were included, being 155 allocated to group 1 (without MS, without glycemic abnormality), 32 to group 2 (without MS, with glycemic abnormality), 104 to group 3 (with MS, without glycemic abnormality), and 163 to group 4 (with MS, with glycemic abnormality). Groups were compared by ANOVA. RESULTS: Those with MS (3 e 4) showed the worst anthropometric and lipid profiles; in group 2, despite higher plasma glucose levels, the mean values of anthropometric variables and lipids did not differ from group 1. The highest mean values of HOMA-IR were found in the groups with MS, while group 2 showed the lowest HOMA-β. Triglyceride was the metabolic variable with the highest correlation coefficients with anthropometry. However, the strongest correlations were those of waist circumference (r = 0.503) and waist-to-height ratio (r = 0.513) with HOMA-IR (p < 0.01). CONCLUSION: Our findings indicate that, in a sample of the Brazilian population, any anthropometric measure identifies individuals with MS, but such measurements seem to be unable to differentiate those with glycemic disturbance. We reinforce the strongest relationship of measures of central adiposity with insulin resistance, suggesting utility for the waist-to-height. An autoimmune component may be contributing to the deterioration of glucose metabolism of individuals from group 2.

Diet quality is associated with leisure-time physical activity in individuals at cardiometabolic risk.

Objectives: We investigated whether diet quality was associated with leisure-time physical activity (LTPA) and television viewing and the associations of these variables with traditional cardiovascular risk factors and novel biomarkers in individuals at cardiometabolic risk. Methods: A total of 193 prediabetic adults (63.7% women, mean age 54.1 years), screened for a diabetes prevention program in Brazil, participated in this cross-sectional study. Clinical data and blood samples were collected for several determinations. Twenty-four-hour recalls were used to calculate the Healthy Eating Index (HEI) adapted to Brazilian dietary habits and the International Physical Activity Questionnaire to assess physical activity level. Analysis of covariance with adjustments for age and body mass index (BMI) was employed to test associations across categories of LTPA and television viewing. Results: Stratifying according to LTPA categories, the most active subset (≥150 minutes/week) showed better HEI scores after adjustments (64.6 ± 11.0, 65.1 ± 10.3, and 68.6 ± 10.8, p = 0.02) and significant higher values of dark green and orange vegetables but not of whole grains (p = 0.06). Active individuals had lower BMI, waist circumference, inflammatory markers, and better insulin sensitivity (p < 0.05). Individuals at the highest category of television viewing had higher age-adjusted BMI (32.0 ± 6.2, 30.7 ± 6.0, and 28.8 ± 4.7 hours/week; p = 0.01) than the others. Time watching television was inversely associated with homeostasis model assessment (HOMA-IR) and C-reactive protein (CRP; p < 0.01) after adjustments but not with lipids and HEI score. Comparisons of individuals with healthy habits (better diet and higher physical activity [PA]), with those with unhealthy habits revealing better anthropometric and cardiometabolic profiles in the former group. Conclusion: Diet quality assessed by the HEI adapted for Brazilian eating habits attained significance in differentiating more active from inactive at-risk individuals during leisure time. Time watching television, as a surrogate of sedentary behavior, is not useful to detect unhealthy diet quality. LTPA is indicative of better cardiometabolic profile reflected by lipid and inflammatory markers and index of insulin resistance.

Realistic changes in monounsaturated fatty acids and soluble fibers are able to improve glucose metabolism

Background/objectivesCardioprotective effects of Mediterranean-style diet have been shown. Instead of excluding foods, replacement or addition may facilitate compliance with impact on glucose metabolism of individuals at cardiometabolic risk. This study investigated the effect of changing selected nutrients intake on glucose metabolism during a lifestyle intervention tailored to living conditions of prediabetic Brazilians.Subjects/methods183 prediabetic adults treated under the Brazilian public health system underwent an 18-month intervention on diet and physical activity. Dietary counseling focused on reducing saturated fat replaced by unsaturated fatty acids. Data were collected at baseline and after follow-up. ANOVA and multiple linear regression were used to test association of changes in nutrients intake with changes in plasma glucose.ResultsChanges in fasting and 2-h plasma glucose but not in weight, HOMA-IR or C-reactive protein decreased after intervention across tertiles of MUFA changes (p-trend 0.017 and 0.024, respectively). Regression models showed that increase in MUFA intake was independently associated with reduction in fasting (β -1.475, p = 0.008) and 2-h plasma glucose (β -3.321, p = 0.007). Moreover, increase in soluble fibers intake was associated with decrease in fasting plasma glucose (β -1.579, p = 0.038). Adjustment for anthropometric measurements did not change the results but did after including change in insulin in the models.ConclusionsIncreases of MUFA and soluble fibers intakes promote benefits on glucose metabolism, independently of adiposity, during a realistic lifestyle intervention in at-risk individuals. Mechanisms mediating these processes may include mainly insulin sensitivity improvement.

Lifestyle intervention using the psychoeducational approach is associated with greater cardiometabolic benefits and retention of individuals with worse health status

Objective This study aimed to compare the effects of two lifestyle intervention programs for type 2 diabetes mellitus (T2DM) prevention - traditional or interdisciplinary psychoeducation-based intervention - in daily habits and cardiometabolic risk factors and investigate the role of the psychoeducational approach for the retention of individuals in the program. Subjects and methods Between 2008 and 2010, in a public health service, 183 pre-diabetic individuals were allocated to two 18-month interventions involving diet and physical activity. Physical activity, diet, quality of life (QOL) and depression and biochemical measurements were obtained. Linear mixed-effect models were used to assess the effect of the interventions. A student t test was used to compare dropouts versus non-dropouts. Results Improvements in energy intake and physical activity were greater in the interdisciplinary than the traditional intervention. A decrease in fat mass and blood pressure was more pronounced with interdisciplinary intervention. Dropouts from the traditional intervention only had higher BMI and lower fiber intake and QOL than non-dropouts. Conclusion The interdisciplinary psychoeducation-based intervention revealed useful for reducing cardiometabolic risk and retaining individuals with worse health profiles. This approach represents a feasible strategy for motivating high-risk individuals to adopt a long-term healthy lifestyle.

Nutritionists’ Health Study cohort: a web-based approach of life events, habits and health outcomes

Introduction Non-communicable chronic diseases (NCCDs) represent a burden for public health. Alongside the established cardiometabolic risk factors such as high blood pressure and disorders of glucose and lipid metabolism, living habits and nutritional status at different stages of life are seen as contributors to this scenario. Gut microbiota composition and subclinical inflammation have been pointed out as underlying mechanisms of NCCDs. Studies involving health professionals have brought relevant contributions to the knowledge about risk factors. Technological advances facilitate data collection and analysis for big samples. A web-based survey addressed to collect data from a cohort study, which is able to identify NCCDs risk factors, is highly desirable. The objective of the Brazilian Nutritionists’ Health Study (NutriHS) is to gather online information on early life events, daily habits, emergent cardiometabolic risk factors and health outcomes of a specific subset of the Brazilian population. Methods and analysis NutriHS, developed at the School of Public Health—University of Sao Paulo, Brazil, is a research initiative that enrols undergraduates of nutrition courses from Brazilian universities and graduated volunteers. A web-based self-administered system was designed to collect health-related data. After fulfilling online questionnaires (socioeconomic, early life events and lifestyle data), participants are invited to a clinical visit for physical examination and laboratory procedures (blood sampling, faeces collection and body composition). At a 3-year interval, they will be invited to repeat similar procedures. Ethics and dissemination The NutriHS research protocol was approved by the Institutional Ethics Committee and is providing promising data which contribute to the understanding of pathophysiological links between early life events, body composition, gut microbiota, and inflammatory and metabolic risk profile. The combination of a friendly tool with the innovative purposes of NutriHS offers a remarkable resource for testing hypotheses about mechanisms of nutrition-related diseases and further planning of preventive programmes in public health.