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

Decision trees to characterise the roles of permeability and solubility on the prediction of oral absorption

Oral absorption of compounds depends on many physiological, physiochemical and formulation factors. Two important properties that govern oral absorption are in vitro permeability and solubility, which are commonly used as indicators of human intestinal absorption. Despite this, the nature and exact characteristics of the relationship between these parameters are not well understood. In this study a large dataset of human intestinal absorption was collated along with in vitro permeability, aqueous solubility, melting point, and maximum dose for the same compounds. The dataset allowed a permeability threshold to be established objectively to predict high or low intestinal absorption. Using this permeability threshold, classification decision trees incorporating a solubility-related parameter such as experimental or predicted solubility, or the melting point based absorption potential (MPbAP), along with structural molecular descriptors were developed and validated to predict oral absorption class. The decision trees were able to determine the individual roles of permeability and solubility in oral absorption process. Poorly permeable compounds with high solubility show low intestinal absorption, whereas poorly water soluble compounds with high or low permeability may have high intestinal absorption provided that they have certain molecular characteristics such as a small polar surface or specific topology. © 2014 Published by Elsevier Masson SAS

The large grey area between ‘bona fide’ and ‘rogue’ stem cell interventions — ethical acceptability and the need to include local variability

This article aims to put into perspective the binary opposition between ‘scientific’ clinical research trials and ‘rogue’ experimental stem cell therapies, and to show why the ethics criteria used by the dominant science community are not suitable for distinguishing between adequate and inadequate treatments. By focusing on the grey area between clinical stem cell trials and stem cell experimentation, the experimental space where patients, medical professionals and life scientists negotiate for diverging reasons and aims, I show why idealised notions of ethics are not feasible for many stem cell scientists in low- and middle-income countries. Drawing on fieldwork in China from 2012 to 2013, the article asks why ‘the unethical’ according to some is acceptable to Chinese life scientists. The case study of stem cell service provider Beike Biotech illustrates how stem cell interventions take place in a large grey area, where narrow notions of ethics are blurred with and supplanted by broader notions of ethics, co-determined by estimations of socio-economic, political and cultural understandings of risk, opportunity and benefit. I borrow the term ‘bionetworking’, understood as the entrepreneurial aspects of scientific networks that engage in creating biomedical products, to analyse various forms of medical experimentation. I speak of the ‘externalisation’ and ‘internalisation’ of local factors to elucidate how features of patient populations and their environments are subsumed in clinical research applications. Compared to polarised views of stem cell therapy, this approach increases the transparency of clinical interventions and broadens our understanding of why ‘stem cell tourism’ to some is ‘stem cell therapy’ to others

Cross-Sector Review of Drivers and Available 3Rs Approaches for Acute Systemic Toxicity Testing

Acute systemic toxicity studies are carried out in many sectors in which synthetic chemicals are manufactured or used and are among the most criticized of all toxicology tests on both scientific and ethical grounds. A review of the drivers for acute toxicity testing within the pharmaceutical industry led to a paradigm shift whereby in vivo acute toxicity data are no longer routinely required in advance of human clinical trials. Based on this experience, the following review was undertaken to identify (1) regulatory and scientific drivers for acute toxicity testing in other industrial sectors, (2) activities aimed at replacing, reducing, or refining the use of animals, and (3) recommendations for future work in this area

Acrylamide-forming potential of potatoes grown at different locations, and the ratio of free asparagine to reducing sugars at which free asparagine becomes a limiting factor for acrylamide formation

Acrylamide is produced from free asparagine and reducing sugars during high-temperature cooking and food processing, and potato products are major contributors to dietary acrylamide intake. The present study analysed twenty varieties of potatoes grown at two sites (Doncaster and Woburn) in the United Kingdom to assess the effect of location of cultivation on acrylamide-forming potential. Analysis of variance revealed a full site by variety nested within type (French fry, boiling and crisping) by storage interaction for acrylamide (p < 0.003, F-test), reducing sugars and total sugars (p < 0.001, F-test). There was much greater free asparagine in potatoes grown at the Doncaster site compared with the Woburn site. Modelling of the relationship between the ratio of free asparagine to reducing sugars and the levels of acrylamide identified a value of 2.257 ± 0.149 as the tipping point in the ratio below which free asparagine concentration could affect acrylamide formation

Equity in the use of antithrombotic drugs, beta-blockers and statins among Finnish coronary patients

Background Earlier studies have mainly reported the use of antithrombotic drugs, beta-blockers and statins among hospital patient populations or MI patients. This study aimed to describe the use of these drugs among middle-aged Finnish coronary patients and to identify patient groups in risk of being prescribed inadequate medication for secondary prevention of coronary heart disease. Methods One-year follow-up survey data from a random sample of a cohort of coronary patients were used along with register data linked to the survey. The response rate was 54% (n = 2650). The main outcome measures were use of antithrombotic drugs, beta-blockers and statins and the data were analysed using logistic regression analysis. Results Among men and women, respectively, 82% and 81% used beta-blockers, 95% and 89% used antithrombotic drugs, and 62% and 59% used statins. Younger men and men from higher socioeconomic groups were more likely to use statins, even after controlling for disease severity and comorbidity. In women, the age trend was reversed and no socioeconomic differences were found. Drug use increased with increased disease severity, but diabetes had only a slight effect. Conclusion The use of antithrombotic drugs and beta-blockers among Finnish coronary patients seemed to be rather appropriate and, to some extent, prescription practices of preventive medication varied according to patients' risk of coronary events. However, statin use was remarkably low among men with low socio-economic status, and there is need to improve preventive drug treatment among diabetic coronary patients.BioMed Central Open acces

Use of varenicline for smoking cessation treatment in UK primary care: an association rule mining analysis

BACKGROUND: Varenicline is probably the most effective smoking cessation pharmacotherapy, but is less widely used than nicotine replacement therapy. We therefore set out to identify the characteristics of numerically important groups of patients who typically do, or do not, receive varenicline in the UK. METHODS: We used association rule mining to analyse data on prescribing of smoking cessation pharmacotherapy in relation to age, sex, comorbidity and other variables from 477,620 people aged 16 years and over, registered as patients throughout 2011 with one of 559 UK general practices in The Health Improvement Network (THIN) database, and recorded to be current smokers. RESULTS: 46,685 participants (9.8% of all current smokers) were prescribed any smoking cessation treatment during 2011, and 19,316 of these (4% of current smokers, 41% of those who received any therapy) were prescribed varenicline. Prescription of varenicline was most common among heavy smokers aged 31–60, and in those with a diagnosis of COPD. Varenicline was rarely used among smokers who were otherwise in good health, or were aged over 60, were lighter smokers, or had psychotic disorders or dementia. CONCLUSIONS: Varenicline is being underused in healthy smokers, or in older smokers, and in those with psychotic disorders or dementia. Since varenicline is probably the most effective available single cessation therapy, this study identifies under-treatment of substantial public health significance

Scaling up cervical cancer screening in the midst of human papillomavirus vaccination advocacy in Thailand

<p>Abstract</p> <p>Background</p> <p>Screening tests for cervical cancer are effective in reducing the disease burden. In Thailand, a Pap smear program has been implemented throughout the country for 40 years. In 2008 the Ministry of Public Health (MoPH) unexpectedly decided to scale up the coverage of free cervical cancer screening services, to meet an ambitious target. This study analyzes the processes and factors that drove this policy innovation in the area of cervical cancer control in Thailand.</p> <p>Methods</p> <p>In-depth interviews with key policy actors and review of relevant documents were conducted in 2009. Data analysis was guided by a framework, developed on public policy models and existing literature on scaling-up health care interventions.</p> <p>Results</p> <p>Between 2006 and 2008 international organizations and the vaccine industry advocated the introduction of Human Papillomavirus (HPV) vaccine for the primary prevention of cervical cancer. Meanwhile, a local study suggested that the vaccine was considerably less cost-effective than cervical cancer screening in the Thai context. Then, from August to December 2008, the MoPH carried out a campaign to expand the coverage of its cervical cancer screening program, targeting one million women. The study reveals that several factors were influential in focusing the attention of policymakers on strengthening the screening services. These included the high burden of cervical cancer in Thailand, the launch of the HPV vaccine onto the global and domestic markets, the country’s political instability, and the dissemination of scientific evidence regarding the appropriateness of different options for cervical cancer prevention. Influenced by the country’s political crisis, the MoPH’s campaign was devised in a very short time. In the view of the responsible health officials, the campaign was not successful and indeed, did not achieve its ambitious target.</p> <p>Conclusion</p> <p>The Thai case study suggests that the political crisis was a crucial factor that drew the attention of policymakers to the cervical cancer problem and led the government to adopt a policy of expanding coverage of screening services. At the same time, the instability in the political system impeded the scaling up process, as it constrained the formulation and implementation of the policy in the later phase.</p