GutSelf: Interindividual Variability in the Processing of Dietary Compounds by the Human Gastrointestinal Tract

Nutritional research is currently entering the field of personalized nutrition, to a large extent driven by major technological breakthroughs in analytical sciences and biocomputing. An efficient launching of the personalized approach depends on the ability of researchers to comprehensively monitor and characterize interindividual variability in the activity of the human gastrointestinal tract. This information is currently not available in such a form. This review therefore aims at identifying and discussing published data, providing evidence on interindividual variability in the processing of the major nutrients, i.e., protein, fat, carbohydrates, vitamins, and minerals, along the gastrointestinal tract, including oral processing, intestinal digestion, and absorption. Although interindividual variability is not a primary endpoint of most studies identified, a significant number of publications provides a wealth of information on this topic for each category of nutrients. This knowledge remains fragmented, however, and understanding the clinical relevance of most of the interindividual responses to food ingestion described in this review remains unclear. In that regard, this review has identified a gap and sets the base for future research addressing the issue of the interindividual variability in the response of the human organism to the ingestion of foods.     

Use of homogenisation pressure to improve quality and functionality of probiotic fermented milks containing Lactobacillus rhamnosus BFE 5264

The effects of 60‐MPa milk homogenisation treatment were investigated on the viability of the probiotic strain Lactobacillus rhamnosus BFE5264, when used as yoghurt co‐starter, as well as on the aroma profile, texture and microstructure of the resulting set‐type fermented milks. The results demonstrated that the combined use of homogenisation pressure and co‐inoculation of the probiotic strain with the traditional yoghurt starters allowed the reduction in the product coagulation time, the increase of the probiotic strain viability and the improvement of the product volatile molecule profiles. The rheological indices and the microstructure results indicated the positive effects of the milk homogenisation treatment on the product viscosity index and exopolysaccharide production.     

Functional Properties of Plasticized Bio-Based Poly(Lactic Acid)_Poly(Hydroxybutyrate) (PLA_PHB) Films for Active Food Packaging

Fully bio-based and biodegradable active films based on poly(lactic acid) (PLA) blended with poly(3-hydroxybutyrate) (PHB) and incorporating lactic acid oligomers (OLA) as plasticizers and carvacrol as active agent were extruded and fully characterized in their functional properties for antimicrobial active packaging. PLA_PHB films showed good barrier to water vapor, while the resistance to oxygen diffusion decreased with the addition of OLA and carvacrol. Their overall migration in aqueous food simulant was determined and no significant changes were observed by the addition of carvacrol and OLA to the PLA_PHB formulations. However, the effect of both additives in fatty food simulant can be considered a positive feature for the potential protection of foodstuff with high fat content. Moreover, the antioxidant and antimicrobial activities of the proposed formulations increased by the presence of carvacrol, with enhanced activity against Staphylococcus aureus if compared to Escherichia coli at short and long incubation times. These results underlined the specific antimicrobial properties of these bio-films suggesting their applicability in active food packaging.     

Proton binding onto soil by nonelectrostatic models: isolation and identification of mineral contributions

In this paper a methodological approach is proposed to validate mechanistic modeling for proton binding onto active sites of mineral and soil samples by reducing the uncertainty and arbitrariness of model schematization. This approach is based on the quantitative formulation (X-ray calibration method) of a simulating mineral mixture (SMM) accounting for the main mineral phases in the soil (quartz, goethite, hematite, muscovite, clinochlore). Mineral and organic contributions were separated by comparing titration curves of river sediment and SMM. Specific mineral contributions to the acid properties of SMM were separated by comparing titration models of SMM and single minerals. Different nonelectrostatic models were used for titrations of SMM and single minerals: two-site/three-KH models (one amphoteric plus one monoprotic site) for clay minerals and SMM; one-site/two-KH models (one amphoteric site) for goethite and hematite; and a one-site/one-KH model (one monoprotic site) for quartz. Crossed-comparisons of titration models allow for identifying and quantifying the specific contributions of the distinct edge hydroxyl groups of iron oxides, clay minerals, and quartz in the different pH ranges. In particularthe amphoteric sites of aluminosilicates mainly contribute in the acid-neutral pH range, the amphoteric sites of iron oxides take part in the neutral-basic range, and finally the monoprotic edge hydroxyl groups of quartz react in the upper basic region of pH. The good simulation of the acid-base properties of SMM (according to single mineral titration models and quantitative composition by X-ray) confirms both model schematization and SMM formulation. Speciation diagrams of the active sites of the different mineral components (aluminosilicates, iron oxides, and quartz) were obtained by implementing the database of a dedicated software with the apparent equilibrium constants regressed by titration modeling of single minerals.     

Occurrence, synthesis, and mammalian cell cytotoxicity and genotoxicity of haloacetamides: an emerging class of nitrogenous drinking water disinfection byproducts

The haloacetamides, a class of emerging nitrogenous drinking water disinfection byproduct (DBPs), were analyzed for their chronic cytotoxicity and for the induction of genomic DNA damage in Chinese hamster ovary cells. The rank order for cytotoxicity of 13 haloacetamides was DIAcAm > IAcAm > BAcAm > TBAcAm > BIAcAm > DBCAcAm > CIAcAm > BDCAcAm > DBAcAm > BCAcAm > CAcAm > DCAcAm > TCAcAm. The rank order of their genotoxicity was TBAcAm > DIAcAm approximately equal to IAcAm > BAcAm > DBCAcAm > BIAcAm > BDCAcAm > CIAcAm > BCAcAm > DBAcAm > CAcAm > TCAcAm. DCAcAm was not genotoxic. Cytotoxicity and genotoxicity were primarily determined by the leaving tendency of the halogens and followed the order I > Br > > Cl. With the exception of brominated trihaloacetamides, most of the toxicity rank order was consistent with structure-activity relationship expectations. For di- and trihaloacetamides, the presence of at least one good leaving halogen group (I or Br but not Cl) appears to be critical for significant toxic activity. Log P was not a factor for monohaloacetamides but may play a role in the genotoxicity of trihaloacetamides and possible activation of dihaloacetamides by intracellular GSH and -SH compounds.     

Yeast diversity in crop-growing environments in Cameroon

In the present study, we have investigated the occurrence of yeast flora on several agricultural products coming from crop-growing environments in Cameroon, to provide better knowledge of the biodiversity of yeast flora, and to thus define the impact of this biodiversity on food products. The yeast biodiversity was investigated using traditional culture-dependent methods, along with culture-independent methods. The culture-dependent approach was carried out using both direct and enrichment procedures, to detect the broadest possible presence of yeast species. A total of 151 strains belonging to 26 different yeast species were isolated and identified using restriction pattern analysis of the internal transcribed spacer region 5.8S-ITS and sequence analysis of D1/D2 domain of 26S rRNA gene. The enrichment isolation procedures carried out in high-sugar media allowed the recognition of fermentative species such as Saccharomyces cerevisiae and Torulaspora delbrueckii, which have previously not been detected using direct isolation methodology. The results of culture-independent method using DGGE patterns and sequencing of the DNA bands revealed a lower number of yeast species when compared with the culture-dependent methodology even if the identification of several yeast species not detected by traditional microbiological procedures such as Candida tropicalis and Hanseniaspora uvarum is allowed. Thus, these multiphasic approaches to study yeast biodiversity (culture-dependent and -independent methods) have allowed us to get a more complete picture of the microbial diversity in these natural environments.     

Stereospecific analysis of triacylglycerol and phospholipid fractions of four freshwater fish species: Salmo trutta, Ictalurus punctatus, Ictalurus melas and Micropterus salmoides

The fatty acid compositions and the positional distributions of fatty acid in triacylglycerol (TAGs) and phospholipid (PLs) fractions of four cultured freshwater fish species (Salmo trutta, Ictalurus punctatus, Ictalurus melas and Micropterus salmoides) were investigated. As regards the TAGs fraction, the S. trutta (trout) and I. punctatus (channel catfish) species had the highest % content in n3 polyunsaturated fatty acids (PUFAs) and the lowest n6/n3 ratio; this ratio resulted always lower than 1 in all the considered fish species. The PLs fraction of the considered fish was very interesting because of the high percentage of PUFAs, both in phosphatidylcholines and in phosphatidylethanolamines. The fatty acid distribution among the three sn-positions of the glycerol backbone was non-random; generally, both n6 and n3 PUFAs were mainly distributed between sn-2- and sn-3-positions of TAGs while the contents in sn-1-position were generally lower; in PLs fraction these fatty acids preferred the sn-2-position.     

Relationship quality profiles and well-being among married adults.

The marital relationship rarely exists in isolation and yet few studies have examined the multiple relationships experienced by most married people. This study used the Convoy Model of Social Relations to examine patterns of multiple relationships and well-being among men and women ages 22 to 79 years (N = 654). Cluster analyses identified profiles of relationship quality among people with spouse, family (children, mother, father), and a best friend (N = 451) and those married with family but no best friend (N = 202). Relationship profiles differed in quality and by gender, race, and age. Among people with best friends, having at least 2 high quality relations, not necessarily with a spouse, is associated with greater well-being. In contrast, among people without best friends, the spousal relation appears to be particularly important for well-being. Although family relationships (e.g., spouse) are important for well-being, interventions should consider the composition and quality of social networks to determine which relationships may need improvement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Why Do We Need More Active ATRP Catalysts?

Atom transfer radical polymerization (ATRP) is a staple technique for the preparation of polymers with well-defined architecture. In ATRP, the catalyst governs the equilibrium between propagating radicals and dormant species, thus affecting the polymerization control for a range of monomers and transferable atoms employed in the process. The design and the use of highly active catalysts could diminish the amount of transition metal complexes, extend ATRP to less active monomers and give access to new chain-end functionalities. At the same time, very active catalysts can be involved in formation of organometallic species. Herein, the role of the catalyst on the ATRP equilibrium is carefully elucidated, together with recent observations on the impact of the catalyst nature on formation of organometallic species and relevant side reactions. Based on this knowledge, a perspective on the benefits and challenges that derive from the use of highly active ATRP catalysts is presented.