INFOGEST static in vitro simulation of gastrointestinal food digestion

peer-reviewedSupplementary information is available at http://dx.doi.org/10.1038/s41596-018-0119-1 or https://www.nature.com/articles/s41596-018-0119-1#Sec45.Developing a mechanistic understanding of the impact of food structure and composition on human health has increasingly involved simulating digestion in the upper gastrointestinal tract. These simulations have used a wide range of different conditions that often have very little physiological relevance, and this impedes the meaningful comparison of results. The standardized protocol presented here is based on an international consensus developed by the COST INFOGEST network. The method is designed to be used with standard laboratory equipment and requires limited experience to encourage a wide range of researchers to adopt it. It is a static digestion method that uses constant ratios of meal to digestive fluids and a constant pH for each step of digestion. This makes the method simple to use but not suitable for simulating digestion kinetics. Using this method, food samples are subjected to sequential oral, gastric and intestinal digestion while parameters such as electrolytes, enzymes, bile, dilution, pH and time of digestion are based on available physiological data. This amended and improved digestion method (INFOGEST 2.0) avoids challenges associated with the original method, such as the inclusion of the oral phase and the use of gastric lipase. The method can be used to assess the endpoints resulting from digestion of foods by analyzing the digestion products (e.g., peptides/amino acids, fatty acids, simple sugars) and evaluating the release of micronutrients from the food matrix. The whole protocol can be completed in ~7 d, including ~5 d required for the determination of enzyme activities.COST action FA1005 INFOGEST (http://www.cost-infogest.eu/ ) is acknowledged for providing funding for travel, meetings and conferences (2011-2015). The French National Institute for Agricultural Research (INRA, www.inra.fr) is acknowledged for their continuous support of the INFOGEST network by organising and co-funding the International Conference on Food Digestion and workgroup meeting

Contribution of oxic methane production to surface methane emission in lakes and its global importance

Recent discovery of oxic methane production in sea and lake waters, as well as wetlands demands re-thinking of the global methane cycle and re-assessment of the contribution of oxic waters to atmospheric methane emission. Here we analysed system-wide sources and sinks of surface-water methane in a temperate lake. Using a mass balance analysis, we show that internal methane production in well-oxygenated surface water is an important source for surface-water methane during the stratified period. Combining our results and literature reports, oxic methane contribution to emission follows a predictive function of littoral sediment area and surface mixed layer volume. The contribution of oxic methane source(s) is predicted to increase with lake size, accounting for the majority (>50 %) of surface methane emission for lakes with surface areas >1 km2

A Review of Energy Drinks and Mental Health, with a Focus on Stress, Anxiety, and Depression

Background: Concerns have been expressed regarding the potential for caffeinated energy drinks to nega- tively affect mental health, and particularly so in young consumers at whom they are often targeted. The prod- ucts are frequently marketed with declarations of increasing mental and physical energy, providing a short- term boost to mood and performance. Although a certain amount of evidence has accumulated to substantiate some of these claims, the chronic effects of energy drinks on mental health also need to be addressed. Methods: To review the relevant literature, PubMed and PsycINFO were searched for all peer-reviewed ar- ticles published in English that addressed associations between energy drink use and mental health outcomes. Case reports were also considered, though empirical studies investigating acute mood effects were excluded as a review of such articles had recently been published. Fifty-six articles were retrieved: 20 of these (along with eight more identified through other means) were included in the current review, and, because the ma- jority addressed aspects of stress, anxiety, and depression, particular focus was placed on these outcomes. Results: Though a number of null findings (and one negative relationship) were observed, the majority of studies examined reported positive associations between energy drink consumption and symptoms of men- tal health problems. Conclusions: Though the findings imply that energy drink use may increase the risk of undesirable mental health outcomes, the majority of research examined utilized cross-sectional designs. In most cases, it was therefore not possible to determine causation or direction of effect. For this reason, longitudinal and inter- vention studies are required to increase our understanding of the nature of the relationships observed

Algal and aquatic plant carbon concentrating mechanisms in relation to environmental change

Carbon dioxide concentrating mechanisms (also known as inorganic carbon concentrating mechanisms; both abbreviated as CCMs) presumably evolved under conditions of low CO2 availability. However, the timing of their origin is unclear since there are no sound estimates from molecular clocks, and even if there were, there are no proxies for the functioning of CCMs. Accordingly, we cannot use previous episodes of high CO2 (e.g. the Palaeocene-Eocene Thermal Maximum) to indicate how organisms with CCMs responded. Present and predicted environmental change in terms of increased CO2 and temperature are leading to increased CO2 and HCO3- and decreased CO32- and pH in surface seawater, as well as decreasing the depth of the upper mixed layer and increasing the degree of isolation of this layer with respect to nutrient flux from deeper waters. The outcome of these forcing factors is to increase the availability of inorganic carbon, photosynthetic active radiation (PAR) and ultraviolet B radiation (UVB) to aquatic photolithotrophs and to decrease the supply of the nutrients (combined) nitrogen and phosphorus and of any non-aeolian iron. The influence of these variations on CCM expression has been examined to varying degrees as acclimation by extant organisms. Increased PAR increases CCM expression in terms of CO2 affinity, while increased UVB has a range of effects in the organisms examined; little relevant information is available on increased temperature. Decreased combined nitrogen supply generally increases CO2 affinity, decreased iron availability increases CO2 affinity, and decreased phosphorus supply has varying effects on the organisms examined. There are few data sets showing interactions among the observed changes, and even less information on genetic (adaptation) changes in response to the forcing factors. In freshwaters, changes in phytoplankton species composition may alter with environmental change with consequences for frequency of species with or without CCMs. The information available permits less predictive power as to the effect of the forcing factors on CCM expression than for their overall effects on growth. CCMs are currently not part of models as to how global environmental change has altered, and is likely to further alter, algal and aquatic plant primary productivity

Selenium-binding protein 1 as a tumor suppressor and a prognostic indicator of clinical outcome

Selenium is a trace element that plays a critical role in physiological processes and cancer prevention, whose functions may be through its effects on selenium-containing proteins. Selenium-binding protein 1 (SBP1) is a member of an unusual class of selenium-containing proteins that may function as a tumor suppressor in multiple cancer types and whose levels have been shown to be lower in cancers as compared to corresponding normal tissues. This review is intended to summarize recent advances in gaining an understanding of the significance of SBP1 in carcinogenesis, and suggest that SBP1 could be developed as a potential biomarker for cancer progression and prognosis