The effect of freeze and hot air drying methods on the retention of total phenolics, antioxidant activity (AA), and color of different cultivars of rose petals was analyzed. Both methods similarly preserved the phenolic content and AA, while freeze drying showed better red color retention. Furthermore, the conditions of total phenolics and AA extraction from two rose cultivars, Lovely Red and Malu, were optimized by response surface methodology through a Box–Behnken design. The solvent exhibited a major effect on the total phenolic content (TPC) and AA. The selected parameters were ethanol 38%, 75 °C, and 30 min. Under these conditions, the predicted values for Lovely Red were 189.3 mg GA/g dw (TPC) and 535.6 mg Trolox/g dw (AA), and those for Malu were 108.5 mg GA/g dw (TPC) and 320.7 mg Trolox/g dw (AA). The experimental values were close to the predicted values, demonstrating the suitability of the model. Ultrasound-assisted extraction increased the AA of the extracts but not the TPC. Fifteen compounds were identified in the Lovely Red cultivar, with no differences between the two drying methods. The results obtained suggest that the analyzed cultivars, particularly the red ones, can be considered a natural source of powerful antioxidant compounds.

The human gastrointestinal tract contains large communities of microorganisms that are in constant interaction with the host, playing an essential role in the regulation of several metabolic processes. Among the gut microbial communities, the gut bacteriome has been most widely studied in recent decades. However, in recent years, there has been increasing interest in studying the influences that other microbial groups can exert on the host. Among them, the gut virome is attracting great interest because viruses can interact with the host immune system and metabolic functions; this is also the case for phages, which interact with the bacterial microbiota. The antecedents of virome-rectification-based therapies among various diseases were also investigated. In the near future, stool metagenomic investigation should include the identification of bacteria and phages, as well as their correlation networks, to better understand gut microbiota activity in metabolic disease progression.

The use of clinical trials to demonstrate effect of foods consumption on human health has increased significantly in recent years at the global level. As in other areas of human health, some authors choose to use parallel trial designs, while others prefer to use crossover designs for these trials. Because crossover trials have the advantage of reducing the number of subjects needed and the economic cost to be performed, they have many advocates within the scientific community. However, these types of tests also have numerous drawbacks, due to the difficulty of carrying out adequate statistical analyses, the lack of reliable standards adapted to them or confounding factors. In this chapter, the advantages and disadvantages of crossover designs and whether they are a recommended option for human nutrition research are shown. The usefulness of design of experiments coupled to crossover trials, especially when comparing various levels of the dependent variable, are also discussed.

El objetivo del presente trabajo ha sido realizar una recopilación de la última evidencia científica acerca de las vías de comunicación entre el sistema nervioso y el intestino, así como la influencia de la microbiota intestinal en la ansiedad. Posteriormente se ha recopilado información acerca de los ensayos preclínicos y clínicos con prebióticos y probióticos para el manejo de la ansiedad y se ha discutido su eficacia y seguridad. También se mencionan las ventajas de la administración de prebióticos y probióticos mediante presentaciones farmacéuticas con respecto a la suplementación por vía alimentaria. Para la realización del mismo se ha realizado una búsqueda en bases de datos científicas, empleando sólo artículos publicados en revistas de prestigio internacional y priorizando los artículos publicados en los últimos años. La microbiota intestinal y el sistema nervioso central se encuentran conectados mediante varios mecanismos, que de manera colectiva se denominan "eje intestino-cerebro". Según evidencias recientes, la vía de comunicación más importante entre ambos órganos la constituye el nervio vago. Los pacientes suelen ser muy reticentes a cambiar de manera importante sus hábitos alimentarios. Así, la administración de prebióticos y probióticos mediante presentaciones farmacéuticas puede facilitar este proceso, controlando mejor la dosis administrada y disminuyendo las tasas de abandono precoz de los tratamientos. Si bien no en todos los casos los prebióticos y probióticos han mostrado efectos positivos, en ninguno se han demostrado efectos adversos en respuesta al empleo de los mismos, por lo que se puede concluir que su administración es segura.