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Background Individual diet components and specific dietary regimens have been shown to impact the gut microbiome. Objectives Here, we explored the contribution of long-term diet by searching for dietary patterns that would best associate with the gut microbiome in a population-based cohort. Methods Using a priori and a posteriori approaches, we constructed dietary patterns from an FFQ completed by 1800 adults in the American Gut Project. Dietary patterns were defined as groups of participants or combinations of food variables (factors) driven by criteria ranging from individual nutrients to overall diet. We associated these patterns with 16S ribosomal RNA–based gut microbiome data for a subset of 744 participants. Results Compared to individual features (e.g. fiber and protein), or to factors representing a reduced number of dietary features, 5 a posteriori dietary patterns based on food groups were best associated with gut microbiome beta diversity (P  ≤ 0.0002). Two patterns followed Prudent-like diets—Plant-Based and Flexitarian—and exhibited the highest Healthy Eating Index 2010 (HEI-2010) scores. Two other patterns presented Western-like diets with a gradient in HEI-2010 scores. A fifth pattern consisted mostly of participants following an Exclusion diet (e.g. low carbohydrate). Notably, gut microbiome alpha diversity was significantly lower in the most Western pattern compared to the Flexitarian pattern (P  ≤ 0.009), and the Exclusion diet pattern was associated with low relative abundance of Bifidobacterium (P  ≤ 1.2 × 10–7), which was better explained by diet than health status. Conclusions We demonstrated that global-diet a posteriori patterns were more associated with gut microbiome variations than individual dietary features among adults in the United States. These results confirm that evaluating diet as a whole is important when studying the gut microbiome. It will also facilitate the design of more personalized dietary strategies in general populations. [ABSTRACT FROM AUTHOR]

This article investigates relationships between public nature and health for unsheltered homeless populations. It examines perceptions of health benefits and harms for people living in public natural areas including local, state, and national forests and parks in the Seattle metropolitan area (USA). Interviews with environmental, social service, and law enforcement professionals who regularly interact with this vulnerable population were conducted and thematically analyzed to understand perceptions of physical and mental health outcomes. Results show professionals' perspectives on the health benefits and detriments of time spent in natural environments and the contextual factors perceived to influence health. Interviewees' observations about the variability of personal circumstances and biophysical, social, and weather conditions encourage the nuanced consideration of how contingent therapeutic landscapes provide deeply needed benefits, but for a population with a diminished capacity to adapt when conditions change. We conclude with insights for future research that directly assesses homeless populations' exposures and health outcomes of living in public natural areas. • Professionals observe benefits and harms of natural area use for homeless populations. • Perceived harms include increased environmental exposures and social vulnerability. • Perceived benefits include privacy, desired social conditions, and reduced stress. • Relationships between nature and health were seen as variable and context dependent. [ABSTRACT FROM AUTHOR]

Objectives: Aim of this study was to assess the effect of a fermented milk product containing Bifidobacterium lactis CNCM I-2494 (FMP) on gastrointestinal (GI) symptoms and exhaled H2 and CH4 during a nutrient and lactulose challenge in patients with irritable bowel syndrome (IBS). Methods: We included 125 patients with IBS (Rome III). Fasted subjects were served a 400ml liquid test meal containing 25g lactulose. The intensity of eight GI symptoms and the amount of exhaled H2 and CH4 were assessed before and during 4h after meal intake. The challenge was repeated after 14 days consumption of FMP or a control product in a double-blind, randomized, parallel design. The metabolic potential of fecal microbiota was profiled using 16S MiSeq analysis of samples obtained before and after the intervention. Results: 106 patients with IBS were randomized. No difference between FMP or control groups was found on GI symptoms or breath H2 and CH4 in the whole cohort. A post-hoc analysis in patients stratified according to their fasting H2 levels showed that in high H2 producers (fasting H2 level≥10ppm, n = 35), FMP consumption reduced fasting H2 levels (p = 0.003) and H2 production during the challenge (p = 0.002) and tended to decrease GI discomfort (p = 0.05) vs. control product. The Prevotella/Bacteroides metabolic potential at baseline was higher in high H2 producers (p<0.05) vs. low H2 producers and FMP consumption reduced this ratio (p<0.05) vs. control product. Conclusions: The response to a fermented milk product containing Bifidobacterium lactis CNCM I-2494 (FMP) in patients with IBS seems to be associated with the metabolic potential of the gut microbiota. Trial registration: ClinicalTrial.gov . These results were presented as congress posters at Digestive Disease Week 2016 in San Diego, USA and United European Gastroenterology Week 2016 in Vienna, Austria. [ABSTRACT FROM AUTHOR]