Establishing What Constitutes a Healthy Human Gut Microbiome: State of the Science, Regulatory Considerations, and Future Directions.

On December 17, 2018, the North American branch of the International Life Sciences Institute (ILSI North America) convened a workshop "Can We Begin to Define a Healthy Gut Microbiome Through Quantifiable Characteristics?" with >40 invited academic, government, and industry experts in Washington, DC. The workshop objectives were to 1) develop a collective expert assessment of the state of the evidence on the human gut microbiome and associated human health benefits, 2) see if there was sufficient evidence to establish measurable gut microbiome characteristics that could serve as indicators of "health," 3) identify short- and long-term research needs to fully characterize healthy gut microbiome-host relationships, and 4) publish the findings. Conclusions were as follows: 1) mechanistic links of specific changes in gut microbiome structure with function or markers of human health are not yet established; 2) it is not established if dysbiosis is a cause, consequence, or both of changes in human gut epithelial function and disease; 3) microbiome communities are highly individualized, show a high degree of interindividual variation to perturbation, and tend to be stable over years; 4) the complexity of microbiome-host interactions requires a comprehensive, multidisciplinary research agenda to elucidate relationships between gut microbiome and host health; 5) biomarkers and/or surrogate indicators of host function and pathogenic processes based on the microbiome need to be determined and validated, along with normal ranges, using approaches similar to those used to establish biomarkers and/or surrogate indicators based on host metabolic phenotypes; 6) future studies measuring responses to an exposure or intervention need to combine validated microbiome-related biomarkers and/or surrogate indicators with multiomics characterization of the microbiome; and 7) because static genetic sampling misses important short- and long-term microbiome-related dynamic changes to host health, future studies must be powered to account for inter- and intraindividual variation and should use repeated measures within individuals

The Genomic Signature of Crop-Wild Introgression in Maize

The evolutionary significance of hybridization and subsequent introgression has long been appreciated, but evaluation of the genome-wide effects of these phenomena has only recently become possible. Crop-wild study systems represent ideal opportunities to examine evolution through hybridization. For example, maize and the conspecific wild teosinte Zea mays ssp. mexicana, (hereafter, mexicana) are known to hybridize in the fields of highland Mexico. Despite widespread evidence of gene flow, maize and mexicana maintain distinct morphologies and have done so in sympatry for thousands of years. Neither the genomic extent nor the evolutionary importance of introgression between these taxa is understood. In this study we assessed patterns of genome-wide introgression based on 39,029 single nucleotide polymorphisms genotyped in 189 individuals from nine sympatric maize-mexicana populations and reference allopatric populations. While portions of the maize and mexicana genomes were particularly resistant to introgression (notably near known cross-incompatibility and domestication loci), we detected widespread evidence for introgression in both directions of gene flow. Through further characterization of these regions and preliminary growth chamber experiments, we found evidence suggestive of the incorporation of adaptive mexicana alleles into maize during its expansion to the highlands of central Mexico. In contrast, very little evidence was found for adaptive introgression from maize to mexicana. The methods we have applied here can be replicated widely, and such analyses have the potential to greatly informing our understanding of evolution through introgressive hybridization. Crop species, due to their exceptional genomic resources and frequent histories of spread into sympatry with relatives, should be particularly influential in these studies

Impact of high fat diets, prebiotics and probiotics on gut microbiota and immune function, with relevance to elderly populations

According to WHO, the number of people over 60 years of age is set to rise to 2 billion by 2050. Dysbiosis of microbial composition and impaired immune function have been observed in elderly persons compared to younger adults. As a result, the aging population has a higher disease risk than other age groups. In addition, high fat intakes have been observed to exert negative effects on microbial composition and immune function in murine studies. Elderly people have higher fat intakes than recommended levels, and this may make them more vulnerable to disease risk. Therefore, the impact of high fat consumption on elderly populations may be of relevance. Prebiotics and probiotics have been shown to have positive effects on microbiota composition and immune function in the elderly. This review describes aged-related changes in gut microbiome of elderly persons. It will also summarise studies concerning the impact of prebiotics, probiotics and high fat diets on microbiota composition and immune function

Energy compensation following consumption of sugar-reduced products: a randomized controlled trial

PURPOSE: Consumption of sugar-reformulated products (commercially available foods and beverages that have been reduced in sugar content through reformulation) is a potential strategy for lowering sugar intake at a population level. The impact of sugar-reformulated products on body weight, energy balance (EB) dynamics and cardiovascular disease risk indicators has yet to be established. The REFORMulated foods (REFORM) study examined the impact of an 8-week sugar-reformulated product exchange on body weight, EB dynamics, blood pressure, arterial stiffness, glycemia and lipemia. METHODS: A randomized, controlled, double-blind, crossover dietary intervention study was performed with fifty healthy normal to overweight men and women (age 32.0 ± 9.8 year, BMI 23.5 ± 3.0 kg/m2) who were randomly assigned to consume either regular sugar or sugar-reduced foods and beverages for 8 weeks, separated by 4-week washout period. Body weight, energy intake (EI), energy expenditure and vascular markers were assessed at baseline and after both interventions. RESULTS: We found that carbohydrate (P < 0.001), total sugars (P < 0.001) and non-milk extrinsic sugars (P < 0.001) (% EI) were lower, whereas fat (P = 0.001) and protein (P = 0.038) intakes (% EI) were higher on the sugar-reduced than the regular diet. No effects on body weight, blood pressure, arterial stiffness, fasting glycemia or lipemia were observed. CONCLUSIONS: Consumption of sugar-reduced products, as part of a blinded dietary exchange for an 8-week period, resulted in a significant reduction in sugar intake. Body weight did not change significantly, which we propose was due to energy compensation

Challenge Demcare: management of challenging behaviour in dementia at home and in care homes:Development, evaluation and implementation of an online individualised intervention for care homes; and a cohort study of specialist community mental health care for families

Background: Dementia with challenging behaviour (CB) causes significant distress for caregivers and the person with dementia. It is associated with breakdown of care at home and disruption in care homes. Challenge Demcare aimed to assist care home staff and mental health practitioners who support families at home to respond effectively to CB. Objectives: To study the management of CB in care homes (ResCare) and in family care (FamCare). Following a conceptual overview, two systematic reviews and scrutiny of clinical guidelines, we (1) developed and tested a computerised intervention; (2) conducted a cluster randomised trial (CRT) of the intervention for dementia with CB in care homes; (3) conducted a process evaluation of implementation of the intervention; and (4) conducted a longitudinal observational cohort study of the management of people with dementia with CB living at home, and their carers. Review methods: Cochrane review of randomised controlled trials; systematic meta-ethnographic review of quantitative and qualitative studies. Design: ResCare – survey, CRT, process evaluation and stakeholder consultations. FamCare – survey, longitudinal cohort study, participatory development design process and stakeholder consultations. Comparative examination of baseline levels of CB in the ResCare trial and the FamCare study participants. Settings: ResCare – 63 care homes in Yorkshire. FamCare – 33 community mental health teams for older people (CMHTsOP) in seven NHS organisations across England. Participants: ResCare – 2386 residents and 861 staff screened for eligibility; 555 residents with dementia and CB; 277 ‘other’ residents; 632 care staff; and 92 staff champions. FamCare – every new referral (n = 5360) reviewed for eligibility; 157 patients with dementia and CB, with their carer; and 26 mental health practitioners. Stakeholder consultations – initial workshops with 83 practitioners and managers from participating organisations; and 70 additional stakeholders using eight group discussions and nine individual interviews. Intervention: An online application for case-specific action plans to reduce CB in dementia, consisting of e-learning and bespoke decision support care home and family care e-tools. Main outcome measures: ResCare – survey with the Challenging Behaviour Scale; measurement of CB with the Neuropsychiatric Inventory (NPI) and medications taken from prescriptions; implementation with thematic views from participants and stakeholders. FamCare – case identification from all referrals to CMHTsOP; measurement of CB with the Revised Memory and Behaviour Problems Checklist and NPI; medications taken from prescriptions; and thematic views from stakeholders. Costs of care calculated for both settings. Comparison of the ResCare trial and FamCare study participants used the NPI, Clinical Dementia Rating and prescribed medications. Results: ResCare – training with group discussion and decision support for individualised interventions did not change practice enough to have an impact on CB in dementia. Worksite e-learning opportunities were not readily taken up by care home staff. Smaller homes with a less hierarchical management appear more ready than others to engage in innovation. FamCare – home-dwelling people with dementia and CB are referred to specialist NHS services, but treatment over 6 months, averaging nine contacts per family, had no overall impact on CB. Over 60% of people with CB had mild dementia. Families bear the majority of the care costs of dementia with CB. A care gap in the delivery of post-diagnostic help for families supporting relatives with dementia and significant CB at home has emerged. Higher levels of CB were recorded in family settings; and prescribing practices were suboptimal in both care home and family settings. Limitations: Functionality of the software was unreliable, resulting in delays. This compromised the feasibility studies and undermined delivery of the intervention in care homes. A planned FamCare CRT could not proceed because of insufficient referrals. Conclusions: A Cochrane review of individualised functional analysis-based interventions suggests that these show promise, although delivery requires a trained dementia care workforce. Like many staff training interventions, our interactive e-learning course was well received by staff when delivered in groups with facilitated discussion. Our e-learning and decision support e-tool intervention in care homes, in its current form, without ongoing review of implementation of recommended action plans, is not effective at reducing CB when compared with usual care. This may also be true for staff training in general. A shift in priorities from early diagnosis to early recognition of dementia with clinically significant CB could bridge the emerging gap and inequities of care to families. Formalised service improvements in the NHS, to co-ordinate such interventions, may stimulate better opportunities for practice models and pathways. Separate services for care homes and family care may enhance the efficiency of delivery and the quality of research on implementation into routine care. Future work: There is scope for extending functional analysis-based interventions with communication and interaction training for carers. Our clinical workbooks, video material of real-life episodes of CB and process evaluation tool resources require further testing. There is an urgent need for evaluation of interventions for home-dwelling people with dementia with clinically significant CB, delivered by trained dementia practitioners. Realist evaluation designs may illuminate how the intervention might work, and for whom, within varying service contexts

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

No effect of 14 day consumption of whole grain diet compared to refined grain diet on antioxidant measures in healthy, young subjects: a pilot study

<p>Abstract</p> <p>Background</p> <p>Epidemiological evidence supports that a diet high in whole grains is associated with lowered risk of chronic diseases included coronary heart disease, obesity, type 2 diabetes, and some types of cancer. One potential mechanism for the protective properties of whole grains is their antioxidant content. The aim of this study was to compare differences in antioxidant measures when subjects consumed either refined or whole grain diets.</p> <p>Methods</p> <p>Twenty healthy subjects took part in a randomized, crossover dietary intervention study. Subjects consumed either a refined grain or whole grain diet for 14 days and then the other diet for the next 14 days. Male subjects consumed 8 servings of grains per day and female subjects consumed 6 servings of grains per day. Blood and urine samples were collected at the end of each diet. Antioxidant measures included oxygen radical absorbance capacity (ORAC) in blood, and isoprostanes and thiobarbituric acid reactive substances (TBARS) in urine.</p> <p>Results</p> <p>The whole grain diet was significantly higher in dietary fiber, vitamin B6, folate, selenium, copper, zinc, iron, magnesium and cystine compared to the refined grain diet. Despite high intakes of whole grains, no significant differences were seen in any of the antioxidant measures between the refined and whole grain diets.</p> <p>Conclusions</p> <p>No differences in antioxidant measures were found when subjects consumed whole grain diets compared to refined grain diets.</p

Lysosomotropic agents as HCV entry inhibitors

HCV has two envelop proteins named as E1 and E2 which play an important role in cell entry through two main pathways: direct fusion at the plasma membrane and receptor-mediated endocytosis. Fusion of the HCV envelope proteins is triggered by low pH within the endosome. Lysosomotropic agents (LA) such as Chloroquine and Ammonium chloride (NH4Cl) are the weak bases and penetrate in lysosome as protonated form and increase the intracellular pH. To investigate the antiviral effect of LA (Chloroquine and NH4Cl) on pH dependent endocytosis, HCV pseudoparticles (HCVpp) of 1a and 3a genotype were produced and used to infect liver cells. The toxicological effects of Chloroquine and NH4Cl were tested in liver cells through MTT cell proliferation assay. For antiviral screening of Chloroquine and NH4Cl, liver cells were infected with HCVpp of 3a and 1a genotype in the presence or absence of different concentrations of Chloroquine and NH4Cl and there luciferase activity was determined by using a luminometer. The results demonstrated that Chloroquine and NH4Cl showed more than 50% reduction of virus infectivity at 50 μM and 10 mM concentrations respectively. These results suggest that inhibition of HCV at fusion step by increasing the lysosomal pH will be better option to treat chronic HCV

Sleep, obesity and cardiometabolic disease in children and adolescents

© 2019 Elsevier Inc. All rights reserved. Obesity and type 2 diabetes mellitus was previously limited to adults, but in recent decades, there has been an increased prevalence among children and adolescents. Given the cost burden and a plethora of adverse consequences with which these diseases are associated, obesity and cardiometabolic diseases now pose a major public health challenge. Obesity and type 2 diabetes mellitus are chronic conditions that commonly track into adulthood and also increase the likelihood of cardiovascular consequences. While these diseases can be caused by genetics, they are largely driven by lifestyle behaviors. Attempts at addressing the global epidemic have targeted behavior modification such as increasing physical activity levels and controlling dietary intake in the hope of restoring energy balance. Sleep impinges on both side of the energy balance equation and there is now an abundance of evidence to suggest that multiple features of sleep may be contributing to the onset and progression of these chronic conditions, which are discussed in this chapter. In particular, we discuss the literature pertaining to the relationship between sleep and obesity as well as type 2 diabetes mellitus in children and adolescents, while also drawing upon crucial information from adult studies. We also highlight potential mechanisms and make recommendations for future approaches which may enhance the effectiveness of interventions targeting the global epidemic of childhood obesity, which is the main driver of metabolic and cardiovascular diseases