Effect of processing on polyamine content and bioactive peptides released after in vitro gastrointestinal digestion of infant formulas.

This study examined the influence of processing on polyamines and peptide release after the digestion of a commercial infant formula designed for children during the first months of life. Polyamine oxidase activity was not suppressed during the manufacturing process, which implicates that polyamine concentrations were reduced over time and during infant formula self-life. In gel electrophoresis, in vitro gastrointestinal digestion of samples with reduced amount of enzymes and time of digestion shows an increase in protein digestibility, reflected in the increase in nonprotein nitrogen after digestion and the disappearance of ß-lactoglobulin and α-lactalbumin bands in gel electrophoresis. Depending on the sample, between 22 and 87 peptides were identified after gastrointestinal digestion. A peptide from ß-casein f(98-105) with the sequence VKEAMAPK and antioxidant activity appeared in all of the samples. Other peptides with antioxidant, immunomodulatory, and antimicrobial activities were frequently found, which could have an effect on infant health. The present study confirms that the infant formula manufacturing process determines the polyamine content and peptidic profile after digestion of the infant formula. Because compositional dissimilarity between human milk and infant formula in polyamines and proteins could be responsible for some of the differences in health reported between breast-fed and formula-fed children, these changes must be taken into consideration because they may have a great effect on infant nutrition and development.

Spinach consumption ameliorates the gut microbiota and dislipaemia in rats with diet-induced non-alcoholic fatty liver disease (NAFLD).

Non-alcoholic fatty liver disease (NAFLD) is defined as the accumulation of fat in liver cells, which causes serious health consequences. Animal and human studies suggest that the gut microbiota plays a role in the pathogenesis of NAFLD. Here, we investigated whether spinach consumption could ameliorate high-fat-diet-induced disturbances in certain intestinal bacterial groups and products derived from their metabolism, such as short-chain fatty acids (SCFAs) and microbial phenolic catabolites. Attention is also paid to blood lipids and glucose. In the study, a rat model of high-fat-diet-induced NAFLD was used. There were six experimental groups: NC (normal diet), NB (normal diet + 2.5% spinach), NA (normal diet + 5% spinach), HC (high-fat diet), HB (high-fat diet + 2.5% spinach) and HA (high-fat diet + 5% spinach). The rats consumed these diets for five weeks, and after that, they were sacrificed and plasma, urine, intestinal content, faeces and liver samples were taken. Biochemical parameters were analyzed in plasma, phenolic catabolites were quantified in the faeces, urine, plasma and liver by UPLC-ESI-MS/MS, and the analysis of the microbiota and SCFAs in the intestinal content was performed by qPCR and GLC. Consumption of a high-fat diet caused NAFLD and dislipaemia and altered the gut microbiota and the pattern of SCFAs and phenolic gut microbial catabolites. Supplementation with spinach partially ameliorated some alterations induced by the high-fat diet, in particular by increasing the Lactobacillus counts, reducing the fasting glucose and total and LDL-cholesterol and preventing excess liver cholesterol accumulation, thereby improving the values of the steatosis biomarkers.

Akkermansia muciniphila: a novel functional microbe with probiotic properties.

Akkermansia muciniphila is an intestinal anaerobe which has been proposed as a new functional microbe with probiotic properties. However, the species is not included in the European Union qualified presumption of safety (QPS) list and has not yet been assessed. Moreover, products containing A. muciniphila are not on the market and are thus controlled by the Novel Foods Regulation, which requires extensive safety assessment. This review addresses the safety aspects of the use of A. muciniphila based on published information on its functions in humans and predictions based on its activity in model animals. Further, comprehensive studies related to A. muciniphila and its safety properties have gradually appeared and are summarised here. Many of the criteria required for novel food safety assessment in Europe can thus be fulfilled. However, studies focusing on the toxicological properties of A. muciniphila, including long-term and reproduction studies, have not so far been reported and are discussed in the light of the observation that most, if not all, healthy subjects are known to carry this intestinal anaerobe. As this also applies to other beneficial bacteria found in the human intestinal tract, the A. muciniphila case can be seen as a model for the comprehensive safety evaluations required by the European authorities.

A method to collect to high volumes of milk from mice

La obtención de leche a partir de ratones de laboratorio (Mus musculus) podría ser interesante para una gran variedad de estudios preclínicos. Son muy escasas las referencias en la literatura científica sobre protocolos que describan como obtener estas muestras, siendo la principal limitación de tales protocolos el pequeño volumen de muestra que es habitual obtener. El objetivo de nuestro estudio fue desarrollar un método funcional para obtener fácilmente cantidades considerables de leche de ratón. Hembras adultas de la variedad no consanguíneas NMRI y de la consanguínea BALB/c con su camada fueron utilizadas en este estudio. La leche fue recogida entre los días 7-12 tras el parto. Las crías fueron separadas de sus madres entre 6-12 horas antes del ordeño para permitir la acumulación de leche en las glándulas. Las hembras fueron anestesiadas usando o una mezcla de midazolam y ketamina, o empleando isoflurano como agente inhalatorio. Para inducir la eyección de la leche, se administro una dosis de 2-8 UI de oxitocina intraperitonealmente. La leche fue recogida usando un sacaleches eléctrico para humanos que fue modificado para adaptarse al pezón de los ratones y para recoger pequeños volúmenes. Con este procedimiento, la cantidad de leche obtenida de los ratones osciló entre los 0,2 y los 1,5 ml. Concluimos por tanto, que este método proporciona una excelente manera de adquirir cantidades considerables de leche de ratón (AU)

Collecting milk samples from mice (Mus musculus) may be interesting for a variety of preclinical research. References in the literature for protocols describing how to milk a dam are scarce, and a major limitation of such protocols is the small sample volume that is generally collected. The aim of our study was to develop a practical protocol to collect substantial amounts of milk from mice. Adult female outbred NMRI and inbred BALB/c mice with nursing litters were used in this study. The milking was carried out on days 7–12 after parturition. The pups were separated from their mothers for 6–12 h before milking to allow accumulation of milk in the glands. Dams were anesthetized using either an injectable mixture of midazolam and ketamine, or by use of the inhalational agent isoflurane. To induce milk flow, the mice were given 2-8 IU of oxytocin intraperitoneally. The milk was collected using an electric human breast pump that was modified to accommodate mouse nipples and to handle small liquid volumes. With this protocol, the total amount of milk collected from each dam per each milking ranged between 0.2 and 1.5 mL. We concluded that this milking method provides an excellent means for acquiring substantial amounts of mouse milk (AU)