Growth of Bifidobacterium species is inhibited by free fatty acids and bile salts but not by glycerides

S.P.B. was supported by the University of Granada grant "Perfeccionamiento de Doctores".High-fat diets have been associated with lower gut and fecal abundances of genus Bifidobacterium. Here, we investigated whether commonly consumed dietary free fatty acids have any detrimental effect on the growth of B. adolescentis, B. bifidum, and B. longum. We found that the presence of free fatty acids in the medium inhibits the growth of Bifidobacterium species to a varying degree, with capric (C10:0), oleic (C18:1), and linoleic (C18:2) acids displaying the largest effect. In comparison, free fatty acids did not affect the growth of Escherichia coli. When fats were added as a mixture of mono- and diacylglycerols, the inhibitory effect on Bifidobacterium growth was abolished.University of Granada grant "Perfeccionamiento de Doctores

Dietary Melanoidins from Biscuits and Bread Crust Alter the Structure and Short-Chain Fatty Acid Production of Human Gut Microbiota

Melanoidins are the products of the Maillard reaction between carbonyl and amino groups of macromolecules and are readily formed in foods, especially during heat treatment. In this study we utilized the three-stage Human Gut Simulator system to assess the effect of providing melanoidins extracted from either biscuits or bread crust to the human gut microbiota. Addition of melanoidins to the growth medium led to statistically significant alterations in the microbial community composition, and it increased short-chain fatty acid and antioxidant production by the microbiota. The magnitude of these changes was much higher for cultures grown with biscuit melanoidins. Several lines of evidence indicate that such differences between these melanoidin sources might be due to the presence of lipid components in biscuit melanoidin structures. Because melanoidins are largely not degraded by human gastrointestinal enzymes, they provide an additional source of microbiota-accessible nutrients to our gut microbes.award "Perfeccionamiento de Doctores" - University of Granada, SpainPlan Propio de Investigacion y Transferencia of the University of GranadaNational Science Foundation (NSF) DBI-1335772Uprising Foods, Inc

Photodissociation chemistry footprints in the Starburst galaxy NGC 253

We report the first detection of PDR molecular tracers, namely HOC+, and CO+, and confirm the detection of the also PDR tracer HCO towards the starburst galaxy NGC 253, claimed to be mainly dominated by shock heating and in an earlier stage of evolution than M 82, the prototypical extragalactic PDR. Our CO+ detection suffers from significant blending to a group of transitions of 13CH3OH, tentatively detected for the first time in the extragalactic interstellar medium. These species are efficiently formed in the highly UV irradiated outer layers of molecular clouds, as observed in the late stage nuclear starburst in M 82. The molecular abundance ratios we derive for these molecules are very similar to those found in M 82. This strongly supports the idea that these molecules are tracing the PDR component associated with the starburst in the nuclear region of NGC 253. A comparison with the predictions of chemical models for PDRs shows that the observed molecular ratios are tracing the outer layers of UV illuminated clouds up to two magnitudes of visual extinction. Chemical models, which include grain formation and photodissociation of HNCO, support the scenario of a photo-dominated chemistry as an explanation to the abundances of the observed species. From this comparison we conclude that the molecular clouds in NGC 253 are more massive and with larger column densities than those in M 82, as expected from the evolutionary stage of the starbursts in both galaxies.Comment: 32 pages, 4 figures, Published in Ap

Prediction of degradation pathways of phenolic compounds in the human gut microbiota through enzyme promiscuity methods

The relevance of phenolic compounds in the human diet has increased in recent years, particularly due to their role as natural antioxidants and chemopreventive agents in different diseases. In the human body, phenolic compounds are mainly metabolized by the gut microbiota; however, their metabolism is not well represented in public databases and existing reconstructions. In a previous work, using different sources of knowledge, bioinformatic and modelling tools, we developed AGREDA, an extended metabolic network more amenable to analyze the interaction of the human gut microbiota with diet. Despite the substantial improvement achieved by AGREDA, it was not sufficient to represent the diverse metabolic space of phenolic compounds. In this article, we make use of an enzyme promiscuity approach to complete further the metabolism of phenolic compounds in the human gut microbiota. In particular, we apply RetroPath RL, a previously developed approach based on Monte Carlo Tree Search strategy reinforcement learning, in order to predict the degradation pathways of compounds present in Phenol-Explorer, the largest database of phenolic compounds in the literature. Reactions predicted by RetroPath RL were integrated with AGREDA, leading to a more complete version of the human gut microbiota metabolic network. We assess the impact of our improvements in the metabolic processing of various foods, finding previously undetected connections with output microbial metabolites. By means of untargeted metabolomics data, we present in vitro experimental validation for output microbial metabolites released in the fermentation of lentils with feces of children representing different clinical conditions

Identificación de IS210, una secuencia de inserción funcional de Azotobacter vinelandii

Resumen de la comunicación presentada en el XXI Congreso Nacional de Microbiología, Sevilla, 17-20 septiembre 2007.Sociedad Española de Microbiologí

Relationship of Thermal Treatment and Antioxidant Capacity in Cooked Foods

Most of the foods we eat undergo a cooking process before they are eaten. During such a process, the non-enzymatic browning occurs, which generates compounds such as furosine, 5-hydroxymethylfurfural (HMF) and furfural. These are considered markers of cookedness and can therefore be used as quality indicators. In this work, we study the production of these compounds in different foods (both of plant and animal origin) that are cooked with different techniques. Additionally, we investigate correlations between the production of these markers of cookedness and the antioxidant capacity produced after in vitro digestion and fermentation. We observe that, in general, cereals and vegetables are more thermally damaged. Toasting and frying produce the highest concentrations of Maillard compounds whereas boiling the lowest. Furosine content shows a significant positive correlation with in vitro digestion data in fried foods, and with fermentation in roasted foods. Furfural content shows a significant positive correlation with in vitro digestion results in roasted foods, specifically in the Folin–Ciocalteu method

Green and white teas as health-promoting foods

This work is part of the doctoral thesis of Daniel Hinojosa- Nogueira conducted within the context of the “Program of Nutrition and Food Sciences” at the University of Granada. This work was supported by the “Plan propio de Investigación y Transferencia” of the University of Granada under the program “Intensificación de la Investigación, modalidad B” granted to José A. Rufián-Henares.Tea is one of the most consumed beverages around the world and as such, it is constantly the object of novel research. This review focuses on the research performed during the last five years to provide an updated view of the current position of tea regarding human health. According to most authors, tea health benefits can be traced back to its bioactive components, mostly phenolic compounds. Among them, catechins are the most abundant. Tea has an important antioxidant capacity and anti-inflammatory properties, which make this beverage (or its extracts) a potential aid in the fight against several chronic diseases. On the other hand, some studies report the possibility of toxic effects and it is advisable to reduce tea consumption, such as in the last trimester of pregnancy. Additionally, new technologies are increasing researchers' possibilities to study the effect of tea on human gut microbiota and even against SARS CoV-2. This beverage favours some beneficial gut microbes, which could have important repercussions due to the influence of gut microbiota on human health."Plan propio de Investigacion y Transferencia" of the University of Granada under the program "Intensificacion de la Investigacion, modalidad B

Toasting time and cooking formulation affect browning reaction products development in corn flakes

During toasting, the last stage of corn flake production, Maillard reaction takes place, favored by the high temperature and low water content. The cooking formulation ingredients influence color and flavor of the final product and, therefore, consumer acceptance. However, some undesirable components are also formed. The impact of cooking formulation and toasting time on color development and on the formation of chemical markers was investigated. Samples (flakes) were equilibrated at water activity (aw) 0.8 and toasted at 230 ° C. After extraction of fluorescent pigments with pronase, fluorescence, absorbance at 420 nm, and furfurals analysis was performed. Sucrose showed a synergistic interaction with malt and salt. Formulation highly affected the amount of HMF and furfural formed. L* and a* were sensitive variables to measure overall browning reaction. These results allow for further understanding of the influence of formulation used during cooking and would help to mitigate the formation of undesirable compounds.EEA PergaminoFil: Cueto, Mario. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); ArgentinaFil: Perez Burillo, Sergio. Universidad de Granada. Facultad de Farmacia. Departamento de Nutrición y Ciencias de los Alimentos; EspañaFil: Rufián Henares, José. Universidad de Granada. Facultad de Farmacia. Departamento de Nutrición y Ciencias de los Alimentos; EspañaFil: Farroni, Abel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Laboratorio de Calidad de Alimento, Suelos y Agua; ArgentinaFil: Buera, M. del Pilar. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentin

An extended reconstruction of human gut microbiota metabolism of dietary compounds

This work was funded by the European Union's Horizon 2020 research and innovation program through the STANCE4HEALTH project (Grant No. 816303).Understanding how diet and gut microbiota interact in the context of human health is a key question in personalized nutrition. Genome-scale metabolic networks and constraint-based modeling approaches are promising to systematically address this complex problem. However, when applied to nutritional questions, a major issue in existing reconstructions is the limited information about compounds in the diet that are metabolized by the gut microbiota. Here, we present AGREDA, an extended reconstruction of diet metabolism in the human gut microbiota. AGREDA adds the degradation pathways of 209 compounds present in the human diet, mainly phenolic compounds, a family of metabolites highly relevant for human health and nutrition. We show that AGREDA outperforms existing reconstructions in predicting diet-specific output metabolites from the gut microbiota. Using 16S rRNA gene sequencing data of faecal samples from Spanish children representing different clinical conditions, we illustrate the potential of AGREDA to establish relevant metabolic interactions between diet and gut microbiota.European Union's Horizon 2020 research and innovation program through the STANCE4HEALTH project 81630

Potential probiotic salami with dietary fiber modulates metabolism and gut microbiota in a human intervention study

A human intervention in 24 healthy volunteers was performed to test the potential health benefits of a fermented salami with a probiotic Lactobacillus rhamnosus HN001 and added citrus fiber. Anthropometric measurements and blood biochemistry did not show any significant differences between pre- and post-intervention during 4 weeks with a daily intake of 30 g of salami, neither with regular salami (control group) nor with reformulated salami (intervention group). However, the inflammatory markers CRP and TNFα decreased significantly after intervention, suggesting a less inflammatory environment after reformulated salami consumption. Antioxidant plasmatic markers also improved within the intervention group. Butyrate production was significantly increased after reformulated salami consumption. Gut microbiota community structure, however, was not significantly shaped by neither regular nor reformulated salami. After the intervention with probiotic salami, L. rhamnosus was detected by quantitative polymerase chain reaction (qPCR) in all samples of the intervention group but not in the control group, showing probiotic effect.This trial was supported by project AVANZA-S from the Spanish Centre for the Development of Industrial Technology (CDTI). It was also supported by a Spanish predoctoral fellowship F.P.U. (ref.: FPU14/ 01192) for S. Perez-Burillo from the Spanish Governmen