The conventional Wien filter is a device with orthogonal static magnetic and electric fields, often used for velocity separation of charged particles. Here we describe the electromagnetic design ...calculations for a novel waveguide RF Wien filter that will be employed to solely manipulate the spins of protons or deuterons at frequencies of about 0.1–2MHz at the COoler SYnchrotron COSY at Jülich. The device will be used in a future experiment that aims at measuring the proton and deuteron electric dipole moments, which are expected to be very small. Their determination, however, would have a huge impact on our understanding of the universe.
Preclinical research has shown that the gastrointestinal microbiota exhibits circadian rhythms and that the timing of food consumption can affect the composition and function of gut microbes. ...However, there is a dearth of knowledge on these relations in humans.
We aimed to determine whether human gastrointestinal microbes and bacterial metabolites were associated with time of day or behavioral factors, including eating frequency, percentage of energy consumed early in the day, and overnight-fast duration.
We analyzed 77 fecal samples collected from 28 healthy men and women. Fecal DNA was extracted and sequenced to determine the relative abundances of bacterial operational taxonomic units (OTUs). Gas chromatography–mass spectroscopy was used to assess short-chain fatty acid concentrations. Eating frequency, percentage of energy consumed before 1400, and overnight-fast duration were determined from dietary records. Data were analyzed by linear mixed models or generalized linear mixed models, which controlled for fiber intake, sex, age, body mass index, and repeated sampling within each participant. Each OTU and metabolite were tested as the outcome in a separate model.
Acetate, propionate, and butyrate concentrations decreased throughout the day (P = 0.006, 0.04, and 0.002, respectively). Thirty-five percent of bacterial OTUs were associated with time. In addition, relations were observed between gut microbes and eating behaviors, including eating frequency, early energy consumption, and overnight-fast duration.
These results indicate that the human gastrointestinal microbiota composition and function vary throughout the day, which may be related to the circadian biology of the human body, the microbial community itself, or human eating behaviors. Behavioral factors, including timing of eating and overnight-fast duration, were also predictive of bacterial abundances. Longitudinal intervention studies are needed to determine causality of these biological and behavioral relations. This trial was registered at clinicaltrials.gov as NCT01925560.
Human milk oligosaccharides (HMOs) are reported to promote epithelial cell differentiation in vitro. The aim of the present study was to assess induction of epithelial cell differentiation by ...individual and combined administration of 3 HMOs.
An in vitro epithelial model of the crypt-villus axis consisting of preconfluent HT-29, preconfluent Caco-2Bbe, and postconfluent Caco-2Bbe cells was used. Cultures were randomized to 17 treatments for 72 hours of incubation: low- and high-dose HMOs (3'sialyllactose 3'SL at 0.2 and 1.0 g/L, 6'siallylactose 6'SL at 0.4 and 1.0 g/L, and 2'fucosyllactose at 0.2 and 2.0 g/L), HMO combinations at both low and high doses, and controls (culture medium, 4 g/L pooled HMO, and lipopolysaccharide).
High doses of individual HMOs (P < 0.05), combined HMOs (P < 0.05), and pooled HMO decreased (P < 0.001) proliferation in preconfluent HT-29 cultures. Pooled means of individual low and high treatments with 3'SL and 6'SL, combinations of 2 or 3 high-dose HMOs, and total HMO significantly reduced (P < 0.05) proliferation in preconfluent Caco-2Bbe cells. HMOs increased differentiation in preconfluent HT-29 and Caco-2Bbe cells. 3'SL and 6'SL increased alkaline phosphatase activity but did not affect disaccharidase activity in postconfluent Caco-2Bbe cells. Apoptosis and necrosis were both decreased (P < 0.001) in postconfluent Caco-2Bbe cells treated with pooled HMO.
HMO treatments inhibited proliferation with some associated enhancement of epithelial differentiation. Effects of HMOs were additive but no specific combinations of HMOs were especially potent. These results suggest that commercially viable individual HMOs and specific combinations may promote intestinal epithelial cell maturation.
Dietary carotenoids, plant pigments with anti-oxidant properties, accumulate in neural tissue and are often found in lower concentrations among individuals with obesity. Given previous evidence of ...negative associations between excess adiposity and memory, it is possible that greater carotenoid status may confer neuroprotective effects among persons with overweight or obesity. This study aimed to elucidate relationships between carotenoids assessed in diet, serum, and the macula (macular pigment optical density (MPOD)) and relational memory among adults who are overweight or obese. Adults aged 25-45 years (
= 94) completed a spatial reconstruction task. Task performance was evaluated for accuracy of item placement during reconstruction relative to the location of the item during the study phase. Dietary carotenoids were assessed using 7-day diet records. Serum carotenoids were measured using high-performance liquid chromatography. Hierarchical linear regression analyses were used to determine the relationship between carotenoids and task performance. Although initial correlations indicated that dietary lutein, beta-carotene, and serum beta-carotene were positively associated with memory performance, these relationships were not sustained following adjustment for age, sex, and BMI. Serum lutein remained positively associated with accuracy in object binding and inversely related to misplacement error after controlling for covariates. Macular carotenoids were not related to memory performance. Findings from this study indicate that among the carotenoids evaluated, lutein may play an important role in hippocampal function among adults who are overweight or obese.
Inulin-type fructans (ITF), including short-chain fructooligosaccharides (scFOS), oligofructose, and inulin, are commonly used fibers that are widely regarded as prebiotic for their ability to be ...selectively utilized by the intestinal microbiota to confer a health benefit. However, to our knowledge the literature thus far lacks a thorough discussion of the evidence from human clinical trials for the prebiotic effect of ITF, including beneficial effects on intestinal microbiota composition and intestinal and extraintestinal processes (e.g., glucose homeostasis, lipids, mineral absorption and bone health, appetite and satiety, inflammation and immune function, and body composition). Additionally, there has been a lack of discussion regarding aspects such as the effect of ITF chain length on its intestinal and extraintestinal effects. The overall objective of this systematic review was to summarize the prebiotic potential of ITF based on the results of human clinical trials in healthy adult populations. Evidence from studies included in the current review suggest that ITF have a prebiotic effect on the intestinal microbiota, promoting the abundances of Bifidobacterium, Lactobacillus, and Faecalibacterium prausnitzii. Beneficial health effects reported following ITF intake include improved intestinal barrier function, improved laxation, increased insulin sensitivity, decreased triglycerides and an improved lipid profile, increased absorption of calcium and magnesium, and increased satiety. Although there is some evidence for differing effects of ITF based on chain length, the lack of direct comparisons and detailed descriptions of physicochemical properties limits the ability to draw conclusions from human clinical studies. Future research should focus on elucidating the mechanisms by which the intestinal microbiota mediates or modifies the effects of ITF on human health and the contribution of individual factors such as age and metabolic health to the movement toward personalization of prebiotic applications.
Statement of Significance: The current review provides a comprehensive synthesis of results from clinical studies in healthy human adults on the prebiotic effects of ITF on the intestinal microbiota and health, with consideration for effects of ITF chain length and individual factors such as baseline intestinal microbiota composition.
Abstract
Human health is intricately intertwined with the composition and function of the trillions of microorganisms that make up the gastrointestinal (GI) microbiome. The GI microbiome is ...essentially a microbial organ that provides metabolic, immunologic, and protective functions for the host. Habitual diet, changes in macronutrient composition, and consumption of nondigestible dietary fibers have all been shown to impact the human GI microbiome. Intriguingly, the impact of diet on the microbiome may be related not only to what humans eat but also to the timing of food consumption. Emerging preclinical research suggests that gut microbes experience diurnal rhythms, and the health effects of eating patterns, including time-restricted feeding and meal frequency, may be related to the GI microbiome. Herein, the complex connections among circadian rhythms, eating behaviors, the GI microbiome, and health are reviewed, highlighting the need for additional translational research in this area.
The Dietary Guidelines for Americans advises on dietary intake to meet nutritional needs, promote health, and prevent diseases. Diet affects the intestinal microbiota and is increasingly linked to ...health. It is vital to investigate the relationships between diet quality and the microbiota to better understand the impact of nutrition on human health.
This study aimed to investigate the differences in fecal microbiota composition in adults from the American Gut Project based on their adherence to the Dietary Guidelines for Americans.
This study was a cross-sectional analysis of the 16S sequencing and food frequency data of a subset of adults (n = 432; age = 18–60 y; 65% female, 89% white) participating in the crowdsourced American Gut Project. The Healthy Eating Index-2015 assessed the compliance with Dietary Guideline recommendations. The cohort was divided into tertiles based on Healthy Eating Index-2015 scores, and differences in taxonomic abundances and diversity were compared between high and low scorers.
The mean Total Score for low-scoring adults (58.1 ± 5.4) was comparable with the reported score of the average American adult (56.7). High scorers for the Total Score and components related to vegetables, grains, and dairy had greater alpha diversity than low scorers. High scorers in the fatty acid component had a lower alpha diversity than low scorers (95% CI: 0.35, 1.85). A positive log-fold difference in abundance of plant carbohydrate–metabolizing taxa in the families Lachnospiraceae and Ruminococcaceae was observed in high-scoring tertiles for Total Score, vegetable, fruit, and grain components (Benjamini–Hochberg; q < 0.05).
Adults with greater compliance to the Dietary Guidelines demonstrated higher diversity in their fecal microbiota and greater abundance of bacteria capable of metabolizing complex carbohydrates, providing evidence on how Dietary Guidelines support the gut microbiota.
The occurrence of compounds of the phenylphenalenone type in
Ensete ventricosum (Musaceae) has been detected for the first time. One novel phenylphenalenone and two compounds already known from the ...Haemodoraceae and other species of the Musaceae were isolated.
Stimulation of gastrointestinal tract maturation is 1 of the many benefits of human milk. Human milk oligosaccharides (HMOs) are abundant in human milk and are reported to promote enterocyte ...differentiation in vitro. The objective of this study was to assess the impact of 3 predominant HMOs on multiple aspects of enterocyte maturation in vitro. Ranging from crypt-like to differentiated enterocytes, we used the well-characterized intestinal cell lines HT-29 and Caco-2Bbe to model early and late stages of differentiation, respectively. With this model of the crypt-villus axis made up of preconfluent HT-29, preconfluent Caco-2Bbe, and postconfluent Caco-2Bbe cultures, we characterized the impact of lacto-N-neotetraose (LNnT), 2'-fucosyllactose (2'FL), and 6'-sialyllactose on epithelial cell kinetics and function. All 3 HMOs dose-dependently inhibited cell proliferation in undifferentiated HT-29 and Caco-2Bbe cultures (P < 0.05). In contrast to previous reports, only treatment with 2'FL at concentrations similar to human milk increased alkaline phosphatase activity by 31% (P = 0.044) in HT-29 cultures and increased sucrase activity by 54% (P = 0.005) in well-differentiated Caco-2Bbe cultures. LNnT at concentrations similar to that reported for human milk increased transepithelial resistance by 21% (P = 0.002) in well-differentiated Caco-2Bbe cells. In summary, all 3 HMOs reduced cell proliferation in an epithelial cell model of the crypt-villus axis. However, effects on differentiation, digestive function, and epithelial barrier function differed between the HMOs tested. These results suggest differential roles for specific HMOs in maturation of the gastrointestinal tract.
Epidemiologic data suggest that diets rich in nuts have beneficial health effects, including reducing total and cause-specific mortality from cancer and heart disease. Although there is accumulating ...preclinical evidence that walnuts beneficially affect the gastrointestinal microbiota and gut and metabolic health, these relations have not been investigated in humans.
We aimed to assess the impact of walnut consumption on the human gastrointestinal microbiota and metabolic markers of health.
A controlled-feeding, randomized crossover study was undertaken in healthy men and women n = 18; mean age = 53.1 y; body mass index (kg/m2): 28.8. Study participants received isocaloric diets containing 0 or 42 g walnuts/d for two 3-wk periods, with a 1-wk washout between diet periods. Fecal and blood samples were collected at baseline and at the end of each period to assess secondary outcomes of the study, including effects of walnut consumption on fecal microbiota and bile acids and metabolic markers of health.
Compared with after the control period, walnut consumption resulted in a 49–160% higher relative abundance of Faecalibacterium, Clostridium, Dialister, and Roseburia and 16–38% lower relative abundances of Ruminococcus, Dorea, Oscillospira, and Bifidobacterium (P < 0.05). Fecal secondary bile acids, deoxycholic acid and lithocholic acid, were 25% and 45% lower, respectively, after the walnut treatment compared with the control treatment (P < 0.05). Serum LDL cholesterol and the noncholesterol sterol campesterol concentrations were 7% and 6% lower, respectively, after walnut consumption compared with after the control treatment (P < 0.01).
Walnut consumption affected the composition and function of the human gastrointestinal microbiota, increasing the relative abundances of Firmicutes species in butyrate-producing Clostridium clusters XIVa and IV, including Faecalibacterium and Roseburia, and reducing microbially derived, proinflammatory secondary bile acids and LDL cholesterol. These results suggest that the gastrointestinal microbiota may contribute to the underlying mechanisms of the beneficial health effects of walnut consumption. This trial was registered at www.clinicaltrials.gov as NCT01832909.
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