Gut microbiome composition in the Hispanic Community Health Study/Study of Latinos is shaped by geographic relocation, environmental factors, and obesity.

Background: Hispanics living in the USA may have unrecognized potential birthplace and lifestyle influences on the gut microbiome. We report a cross-sectional analysis of 1674 participants from four centers of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), aged 18 to 74 years old at recruitment.Results: Amplicon sequencing of 16S rRNA gene V4 and fungal ITS1 fragments from self-collected stool samples indicate that the host microbiome is determined by sociodemographic and migration-related variables. Those who relocate from Latin America to the USA at an early age have reductions in Prevotella to Bacteroides ratios that persist across the life course. Shannon index of alpha diversity in fungi and bacteria is low in those who relocate to the USA in early life. In contrast, those who relocate to the USA during adulthood, over 45 years old, have high bacterial and fungal diversity and high Prevotella to Bacteroides ratios, compared to USA-born and childhood arrivals. Low bacterial diversity is associated in turn with obesity. Contrasting with prior studies, our study of the Latino population shows increasing Prevotella to Bacteroides ratio with greater obesity. Taxa within Acidaminococcus, Megasphaera, Ruminococcaceae, Coriobacteriaceae, Clostridiales, Christensenellaceae, YS2 (Cyanobacteria), and Victivallaceae are significantly associated with both obesity and earlier exposure to the USA, while Oscillospira and Anaerotruncus show paradoxical associations with both obesity and late-life introduction to the USA.Conclusions: Our analysis of the gut microbiome of Latinos demonstrates unique features that might be responsible for health disparities affecting Hispanics living in the USA

Author Correction: Gut microbiome composition in the Hispanic Community Health Study/Study of Latinos is shaped by geographic relocation, environmental factors, and obesity.

Following publication of the original paper [1], an error was reported in the third paragraph in the section "Analysis of GMB composition and its correlates" (page 3 of the PDF). The first sentence of the text should refer to Table 2, but mistakenly refers to Table 1

Prevalence of Major Cardiovascular Risk Factors and Cardiovascular Diseases Among Hispanic/Latino Individuals of Diverse Backgrounds in the United States

Major cardiovascular diseases (CVDs) are leading causes of mortality among US Hispanic and Latino individuals. Comprehensive data are limited regarding the prevalence of CVD risk factors in this population and relations of these traits to socioeconomic status (SES) and acculturation

CONFORMATION-SPECIFIC AND MASS-RESOLVED, INFRARED-POPULATION TRANSFER SPECTROSCOPY OF THE MODEL γ2\gamma^{2}-PEPTIDE Ac-γ\gamma2^{2}-hPhe-NHMe: EVIDENCE FOR THE PRESENCE OF INTRAMOLECULAR AMIDE-AMIDE STACKING INTERACTIONS.

W.~Chin, F.~Piuzzi, I.~Dimicoli, and M.~Mons, \textit{PCCPE.~E.~Baquero, W.~H.~James~III, S.~H.~Choi, S.~H.~Gellman, and T.~S.~Zwier, \textit{J. Am. Chem. Soc.Author Institution: Department of Chemistry, Purdue University, West Lafayette, IN 47907; School of Chemistry, University of Bristol, Bristol BS8 1TS, UK; Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706Recently, double resonance spectroscopy has been utilized to elucidate the conformational preferences of natural, \textbf{2006}, \textit{8}, 1033.} and synthetic, \textbf{2008}, \textit{130}, 4784.} peptide mimetics. These studies demonstrated the power of double resonance methods and highlighted the ability of even short peptide mimetics to form a variety of intramolecular hydrogen bonded architectures. Currently, we have undertaken a detailed study of a model $\gamma$$^{2}$-peptide using double resonance spectroscopy. Conformation-specific IR spectra in the amide NH and amide I stretch spectral regions of Ac-$\gamma$$^{2}$-hPhe-NHMe provide evidence for three unique conformational isomers in a jet-cooled environment. The results of DFT and MP2 calculations will be presented as a basis for assignment of the experimentally resolved conformers. Two conformers form nine atom, intramolecular hydrogen bonded rings, which differ by the position of the aromatic ring relative to the peptide backbone. The third conformer does not contain intramolecular hydrogen bonding, but forms an intramolecular, amide-amide stacking structural motif, which when analyzed with the quantum theory of Atoms In Molecules is shown to contain an interaction between the carbon atom of the acetylated N-terminal amide and the nitrogen atom of the methylated C-terminal amide. In an effort to quantitatively assess the competition between hydrogen bonded and amide-amide stacked conformers, mass-resolved, infrared-population transfer spectroscopy was developed, where the IR and molecular beams are counter-propagated allowing for a re-cooling step prior to detection via resonant two-photon ionization spectroscopy. Using this method the fractional abundances of each conformer were experimentally determined

Anaerobic pathogens associated with OSA may contribute to pathophysiology via amino-acid depletionResearch in context

Summary: Background: The human microbiome is linked to multiple metabolic disorders such as obesity and diabetes. Obstructive sleep apnoea (OSA) is a common sleep disorder with several metabolic risk factors. We investigated the associations between the gut microbiome composition and function, and measures of OSA severity in participants from a prospective community-based cohort study: the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). Methods: Bacterial-Wide Association Analysis (BWAS) of gut microbiome measured via metagenomics with OSA measures was performed adjusting for clinical, lifestyle and co-morbidities. This was followed by functional analysis of the OSA-enriched bacteria. We utilized additional metabolomic and transcriptomic associations to suggest possible mechanisms explaining the microbiome effects on OSA. Findings: Several uncommon anaerobic human pathogens were associated with OSA severity. These belong to the Lachnospira, Actinomyces, Kingella and Eubacterium genera. Functional analysis revealed enrichment in 49 processes including many anaerobic-related ones. Severe OSA was associated with the depletion of the amino acids glycine and glutamine in the blood, yet neither diet nor gene expression revealed any changes in the production or consumption of these amino acids. Interpretation: We show anaerobic bacterial communities to be a novel component of OSA pathophysiology. These are established in the oxygen-poor environments characteristic of OSA. We hypothesize that these bacteria deplete certain amino acids required for normal human homeostasis and muscle tone, contributing to OSA phenotypes. Future work should test this hypothesis as well as consider diagnostics via anaerobic bacteria detection and possible interventions via antibiotics and amino-acid supplementation. Funding: Described in methods

SINGLE-CONFORMATION SPECTROSCOPIC INVESTIGATION OF PEPTIDE BUILDING BLOCKS IN THE AMIDE I SPECTRAL REGION: COMPARISON OF EXPERIMENT TO DENSITY FUNCTIONAL THEORY AND THE TRANSITION DIPOLE COUPLING MODEL

Author Institution: Department of Chemistry, Purdue University, West Lafayette, IN 47907; School of Chemistry, University of Bristol, Bristol BS8 1TS, UK; Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706IR/UV double-resonance spectroscopy has been utilized to elucidate the intrinsic conformational preferences of naturally occurring $\alpha$-peptides and synthetic $\beta$-, $\alpha$/$\beta$-, and $\gamma$-peptides. These studies used as the primary spectral probe the amide NH stretch region, demonstrating the power of double-resonance methods and highlighting the ability of even short peptide mimics to form a variety of intramolecular hydrogen bonded architectures. In this talk, we extend our studies of the full complement of some 30 conformations of these molecules into the mid-infrared, where the Amide I region (1600-1800 \wn) can provide complementary insight to the nature of the hydrogen bonding involved. Our goal is to provide a unique data set on which to test current theories of Amide I coupling used in the analysis of multi-dimensional infrared spectra of peptides in solution. The spectroscopic data will be compared with density functional theory (DFT) calculations and the transition dipole coupling (TDC) model. The results present the dependence of the C=O stretch vibrations on hydrogen bonding, inter-amide distance, and through-bond and through-space coupling