Prebiotic effects of pectooligosaccharides obtained from lemon peel on the microbiota from elderly donors using an in vitro continuous colon model (TIM-2).

The development of new prebiotics capable of modulating the gut microbiota in the elderly has become an area of great interest due to the particular vulnerability and frailty of this population. In the present work, mixtures of pectin-derived oligosaccharides (POS) were manufactured from lemon peel waste and evaluated for their capability to modulate the gut microbiota using, as inoculum, a pool of faeces from elderly donors. Both changes in the microbiota and the metabolic activity were assessed and compared with commercial fructooligosaccharides (FOS) and the standard ileal efflux medium (SIEM) using the TIM-2 in vitro colon model. POS fermentation led to similar or even better effects than FOS at phylum, family and genus levels. Higher increments in beneficial species such as Faecalibacterium prausnitzii and larger alpha diversity values were observed with POS in comparison with FOS and in some cases with SIEM. The PCoA analyses revealed that the microbial profiles resulting from POS and FOS bacterial fermentation were rather similar and differed from those observed after SIEM fermentation. Finally, although butyrate cumulative production was comparable among substrates, the highest short chain fatty acid (SCFA) and the lowest branched chain fatty acid (BCFA) cumulative production was observed in POS experiments. These results support the potential of pectin-derived oligosaccharides as prebiotic candidates targeting gut health in the elderly.

Potential of High- and Low-Acetylated Galactoglucomannooligosaccharides as Modulators of the Microbiota Composition and Their Activity: A Comparison Using the In Vitro Model of the Human Colon TIM-2.

High- and low-acetylated galactoglucomannooligosaccharides (GGMOS_Ac and GGMOS, respectively) were assayed as substrates in the TIM-2 in vitro colon model using, as inoculum, fecal microbiota from the elderly. The effects on the microbiota and their activity were also compared to a standard ileal efflux medium (SIEM). GGMOS resulted in higher organic acid productions and higher short-chain fatty acids/total organic acid molar ratios. Although comparable Actinobacteria abundances were observed with both substrates, GGMOS fermentation led to higher Firmicutes/Bacteroidetes ratios and lower Proteobacteria percentages than GGMOS_Ac. No differences were found concerning the percentages of beneficial genus such as Blautia, Faecalibacterium, Coprococcus, or Bifidobacterium. However, higher bacterial diversities and numbers of genera such as Oscillospira and Lachnospira were found with GGMOS_Ac. This suggests that GGMOS would be more suitable substrates for the elderly, even though GGMOS_Ac promoted positive effects that support the interest of further research using these oligosaccharides as "carriers" of desired substituents.

Potential of Fructooligosaccharides and Xylooligosaccharides as Substrates To Counteract the Undesirable Effects of Several Antibiotics on Elder Fecal Microbiota: A First in Vitro Approach.

Fructooligosaccharides (FOS) and xylooligosaccharides (XOS) were employed as substrates for in vitro fermentations to assess their capacity to counteract the effects caused by three antibiotics (ABs) at different doses on the elderly gut microbiota and its metabolic activity. The AB type and dose scarcely affected the total bacterial numbers and the microbiota composition after 24 h. However, in the presence of ABs, the relative percentages of Lactobacillus decreased (from 11.4% to 3.2% in the presence of XOS1), as well as the butyrate production, whereas the population of Bacteroides increased significantly in the presence of XOS1 (from 27.5% to 55.7%). FOS were able to counteract these effects by increasing the butyrate production and the number of Lactobacillus, while maintaining the number of Bacteroides almost constant and decreasing the clostridia. XOS2 (mainly DP = 2-4) also showed ability to increase the percentages of Bifidobacterium and the production of both butyrate and acetate.

Manufacture and Properties of Glucomannans and Glucomannooligosaccharides Derived from Konjac and Other Sources.

Glucomannans (GM) are polymers that can be found in natural resources, such as tubers, bulbs, roots, and both hard- and softwoods. In fact, mannan-based polysaccharides represent the largest hemicellulose fraction in softwoods. In addition to their structural functions and their role as energy reserve, they have been assessed for their healthy applications, including their role as new source of prebiotics. This paper summarizes the scientific literature regarding the manufacture and functional properties of GM and their hydrolysis products with a special focus on their prebiotic activity.

Production, Purification, and in Vitro Evaluation of the Prebiotic Potential of Arabinoxylooligosaccharides from Brewer's Spent Grain.

Brewer's spent grain (BSG) samples were subjected to a two-step aqueous processing (starch extraction and autohydrolysis) in order to assess their potential as a raw material for obtaining a mixture of arabinoxylooligosaccharides (AXOS) suitable to be use as prebiotics for elderly. After hydrothermal treatment, the liquors were refined by a sequence of purification and conditioning steps including membrane filtration, enzymatic hydrolysis, and ion exchange. The presence of both substituted (degree of polimerization (DP) = 2-10) and unsubstituted (DP = 2-16) oligosaccharides made up of xylose and arabinose (AXOS) were confirmed in purified mixtures (in which total OS content = 84% w/w) by using chromatographic techniques and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Finally, AXOS were evaluated for their prebiotic activity by in vitro fermentation assays using fecal inocula from elderly people, demonstrating that AXOS were slightly better substrates than FOS, in terms of bacterial population shifts as in the production of SCFA.

Evaluation of the production of paralytic shellfish poisoning toxins by extracellular bacteria isolated from the toxic dinoflagellate Alexandrium minutum.

The purpose of the study was to determine if paralytic shellfish poisoning (PSP) toxins are present in extracellular bacteria isolated from a toxic strain of the dinoflagellate Alexandrium minutum. A quantitative analysis was carried out of viable culturable bacteria attached to the surface of dinoflagellates and of bacteria present in dinoflagellate culture medium. A numerical taxonomy study was undertaken for presumptive identification of bacteria attached to the surface of dinoflagellates. Members of the following genera were detected on the cell surface of A. minutum: Cellulophaga, Marinomonas, Pseudoalteromonas, and Vibrio. The presence of intracellular PSP toxins in bacteria isolated from the cell surface of dinoflagellates was analysed by high-performance liquid chromatography with fluorescence detection (HPLC-FLD). Compounds that eluted at the same time as the standards of the PSP toxins GTX-2, GTX-3, GTX-4, dcGTX-2, and dcGTX-3 were present in some of the bacterial cell extracts. Natural fluorescent bacterial compounds, coeluting with some PSP toxins, were also detected. The results obtained showed that the fluorescent compounds, identified as putative PSP toxins by HPLC-FLD, did not correspond to any PSP analogue. This allowed us to reject the hypothesis that extracellular bacteria attached to the surface of dinoflagellates produce PSP toxins.

Effect of bacterial epiflora on egg hatching of the Atlantic sardine (Sardina pilchardus).

The aim of this work was to study the influence of bacterial epiflora on egg hatching of the sardine (Sardina pilchardus) obtained from a natural environment (Ría de Vigo, Spain) during the spawning season of the sardine (from January to June). Total bacteria, viable bacteria or the presence of specific potential pathogens for eggs, such as Pseudoalteromonas piscicida and Tenacibaculum (Flexibacter) ovolyticus, did not affect the viability of sardine eggs. Additionally, no relationship was observed between the presence of Vibrio spp., pathogenic for fish larvae, and the egg hatching. This was probably because the amount of bacteria associated with the eggs were between 10(2) and 10(4) orders lower than those found so far on the eggs of different fish species in rearing systems. Therefore, epiphytic bacteria did not affect the wild sardine eggs and, hence, in the area studied, it is probably not an important factor affecting annual recruitment success of this pelagic fish species.

Calidad y estilo de vida en estudiantes de medicina y enfermeria / Quality and style of life in sutdents of medicine and nursing

El cuestionario general de salud en el formato de 12 preguntas; el Indice de Calidad de Vida en su versión al español, y un instrumento autóctono para explorar tiempo promedio semanal dedicado a actividades relevantes para inferir estilo de vida, fueron aplicados a 127 estudiantes de medicina y 69 de enfermería seleccionados en forma aleatoria. Tres alumnos obtuvieron 4 en el cuestionario de salud fueron excluídos, y la muestra final fue de 125 estudiantes de medicina (80 alumnas y 45 alumnos) de la Facultad Universitaria Calixto García y 68 estudiantes de enfermería de un tecnológico de Ciudad Habana, (43 alumnas y 25 alumnos). Los resultados evidenciaron calificaciones similares en los 10 Items del cuestionario de calidad de vida, con la excepción de los referentes apoyo emocional y social; apoyo y servicios comunitarios; y satisfacción personal en los que el grupo de enfermería sobre todo las alumnas, arrojó cifras promedio algo menores. La calificación global del Indice de Calidad de Vida es de 70,7; 76,5; 77,0; y 78,4 en el orden de estudiantes de enfermería; asi como estudiantes de medicina. El cuestionario fue altamente valorado como comprensible y factible, y la exploración del tiempo dedicado al sueño, estudio, familia, pareja, deportes, asi como a actividades sociales, culturales y recreativas apuntaron hacia estilos de vida sanos

Calidad y estilo de vida en estudiantes de medicina y enfermeria / Quality and style of life in sutdents of medicine and nursing

El cuestionario general de salud en el formato de 12 preguntas; el Indice de Calidad de Vida en su versión al español, y un instrumento autóctono para explorar tiempo promedio semanal dedicado a actividades relevantes para inferir estilo de vida, fueron aplicados a 127 estudiantes de medicina y 69 de enfermería seleccionados en forma aleatoria. Tres alumnos obtuvieron 4 en el cuestionario de salud fueron excluídos, y la muestra final fue de 125 estudiantes de medicina (80 alumnas y 45 alumnos) de la Facultad Universitaria Calixto García y 68 estudiantes de enfermería de un tecnológico de Ciudad Habana, (43 alumnas y 25 alumnos). Los resultados evidenciaron calificaciones similares en los 10 Items del cuestionario de calidad de vida, con la excepción de los referentes apoyo emocional y social; apoyo y servicios comunitarios; y satisfacción personal en los que el grupo de enfermería sobre todo las alumnas, arrojó cifras promedio algo menores. La calificación global del Indice de Calidad de Vida es de 70,7; 76,5; 77,0; y 78,4 en el orden de estudiantes de enfermería; asi como estudiantes de medicina. El cuestionario fue altamente valorado como comprensible y factible, y la exploración del tiempo dedicado al sueño, estudio, familia, pareja, deportes, asi como a actividades sociales, culturales y recreativas apuntaron hacia estilos de vida sanos(AU)

Bacteria associated with sardine (Sardina pilchardus) eggs in a natural environment (Ría de Vigo, Galicia, northwestern Spain).

Abstract The present study was undertaken to describe the epiflora of the eggs of an important fishing species collected in a coastal zone. Microflora associated with sardine (Sardina pilchardus) eggs collected in the Ría de Vigo was examined from January to June 2000. The count was carried out in three different ways: a total direct count by epifluorescence, a heterotrophic bacteria count on marine agar (MA) and a total vibrio count on thiosulfate citrate bile sucrose (TCBS). It was observed that the counts of total bacteria by epifluorescence were always higher by 2-3 logarithms than the bacterial counts on MA, and by 3-4 logarithms than the count of vibrios on TCBS. In both cases the differences were statistically significant. Throughout the sampling period only a slight variation was observed in the counts undertaken, and in the measured physicochemical parameters. For the qualitative study, 250 strains isolated from MA and 81 strains recovered on TCBS were identified. Members of the genera Vibrio, Pseudoalteromonas, Pseudomonas and Moraxella were found to dominate on the culturable adherent microflora of sardine eggs and Aeromonas, Tenacibaculum (Flexibacter), Flavobacterium and Cytophaga spp. were present in minor amounts. Vibrio anguillarum and Vibrio fischeri, pathogens of fish larvae, as well as Tenacibaculum ovolyticum, a pathogen of fish eggs, were detected.