The Gut Brain-Axis in Neurological Diseases

Abstract Recent evidence suggests that dysfunction of the gut-brain axis may be an important factor contributing to many diseases of the nervous system. Increased gut permeability associated with chronic gastrointestinal dysfunction, as well as changes in the composition of the gut microbiota could contribute to exposure of the enteric and central nervous system to pathogens and its metabolites, including endotoxins and pro-inflammatory cytokines. As a consequence, dysfunction of the host's immune system could contribute to an abnormal immunological response leading to auto-immune conditions, such as multiple sclerosis. So far, gut dysbiosis has been reported in association with Parkinson's disease, Alzheimer's disease, multiple sclerosis, neurodevelopmental and neuropsychiatric conditions, and cerebrovascular disease. These findings suggest that the possibility of targeting the gut microbiota could become a future therapeutic option to treat these conditions. However, before this knowledge can be useful in the clinical setting, more data is needed to establish clear causal relationships between dysfunction of the gut-brain axis and neurological diseases.

Recomendaciones y efectos de la fibra dietaria en niños / Recommendations and effects of dietary fiber for children

Conocida es la influencia de la fibra dietaria sobre los efectos mecánicos a nivel gastrointestinal, la composición y modulación de la microbiota intestinal y su función en la actividad metabólica y nutricional en adultos. En niños y adolescentes estos efectos son menos conocidos, generando interesantes áreas de investigación y desarrollo científico que nos puedan entregar mayor conocimiento de sus repercusiones a nivel fisiológicos y fisiopatológicos. Esta revisión tiene como objetivo entregar información actualizada sobre las diferentes clasificaciones de fibra, sus principales funciones digestivas y metabólicas, así como las recomendaciones de ingesta diaria en pediatría.

Among adults, the influence of dietary fiber on mechanical effects at the gastrointestinal level, the composition and modulation of the intestinal microbiota and function in the metabolic and nutritional activity is known. However, in children and adolescents, these effects are less known, generating interesting areas of research and development that could provide additional knowledge at the physiological and pathophysiological level. The aim of this review was to provide updated information about the different classifications of fiber, the principal digestive and metabolic functions, as well as recommendations for daily intake for pediatric populations.

La vesícula biliar como reservorio y protectora del tracto digestivo / The gallbladder as reservoir and protector of the digestive tract

Introducción: Estudios anatomofisiológicos y biomoleculares de la vesícula biliar han permitido redefinir su función no solo como reservorio de la secreción biliar, sino como protectora intestinal, concepto que se fundamenta en su capacidad de control de la bioactividad y la toxicología de los ácidos biliares, el metabolismo del colesterol, los fosfolípidos y otros componentes de la secreción hepatobiliar. Objetivo: Describir las actualidades de la funcionabilidad de la vesícula biliar como reservorio y protectora del tracto digestivo dirigido a que cirujanos generales, gastroenterólogos, clínicos y fisiólogos amplíen sus conocimientos sobre la función de la vesícula biliar. Métodos: Se realiza una revisión crítica de las funciones de la vesícula biliar que favorecen mantener la integridad de la pared intestinal. Conclusión: La descripción actualizada de la funcionabilidad de la vesícula biliar ofrece un resultado relevante dentro del marco conceptual en relación a su función protectora que se traduce en el mantenimiento de la integridad del epitelio y la microbiota intestinal(AU)

Introduction: Anatomic-physiological and biomolecular studies of the gallbladder have made it possible to redefine its function not only as a reservoir for bile secretion, but also as intestinal protector. This concept is supported by its capacity to control the bioactivity and toxicology of bile acids, cholesterol metabolism, phospholipids and other components of hepatobiliary secretion. Objective: Present an update on the role of the gallbladder as reservoir and protector of the digestive tract intended for general surgeons, gastroenterologists, clinicians and physiologists to broaden their knowledge about the functions of the gallbladder. Methods: A critical review was conducted of the functions of the gallbladder which facilitate maintenance of the integrity of the intestinal wall. Conclusion: The updated description of the functions of the gallbladder is a relevant contribution to the conceptual framework of its protective function, which ensures the maintenance of the integrity of the epithelium and the intestinal microbiota(AU)

Desarrollo y cambios con la edad en el tubo digestivo, hígado y páncreas / Digestive tract, liver and pancreas: development and changes with age

An adequate functioning of the digestive tract, liver and pancreas is fundamental to providing the organism with the necessary conditions for its development and maintaining its digestive and systemic homeostasis. Life expectancy has increased, it is estimated that adults over 65 years old by 2050, will represent 25% of the local population. The morphological and functional changes associated with aging in the digestive system, liver and pancreas are modest except for those that occur in the microbiota. Recently it has been possible to establish the contribution of the microbiota to life expectancy and establish a link between gastrointestinal microbiota, inflammation associated with aging (inflammaging) and survival. This represents a shift in the paradigm of our understanding physiology, chronic diseases, neoplasms and for the development of new therapies.

Un adecuado funcionamiento del tubo digestivo, hígado y páncreas es fundamental para poder brindar al organismo las condiciones necesarias para su desarrollo y mantener su homeostasis digestiva y sistémica. La expectativa de vida se ha incrementado, estimándose a nivel nacional que para el año 2050 los adultos mayores de 65 años representarán el 25% de la población. Los cambios morfológicos y funcionales asociados al envejecimiento en el aparato digestivo, hígado y páncreas son modestos a excepción, de los que se producen en la microbiota. Recientemente se ha podido establecer la contribución de la microbiota a la esperanza de vida y establecer un nexo entre microbiota gastrointestinal, inflamación asociada al envejecimiento y sobrevida. Esto representa un cambio en el paradigma sobre cómo comprendemos la fisiología, las patologías crónicas, neoplásicas y en el desarrollo de nuevas terapias.

Evaluation of growth performance and gastro-intestinal parameters on the response of weaned piglets to dietary organic acids

ABSTRACT Two experiments (E) were carried out to evaluate the effects of fumaric acid and an acidifier blend [composed by calcium formate, calcium lactate and medium-chain fatty acids (capric and caprylic)] in piglet diets containing colistin (40 ppm) or halquinol (120 ppm) on performance, diarrhea incidence (E1), organs relative weight, pH values, intestinal morphometry and microbiota (E2). In E1, 192 and E2, 24 piglets weaned at 21-day-old were randomly assigned to blocks with 2x2 factorial arrangement of treatments [absence or presence of fumaric acid x absence or presence of acidifier blend], six replicates of eight (E1) and one piglet per pen (E2). For E1, the treatments were control (CD): no acidifier product + 40 ppm of colistin, FA: fumaric acid in absence of acidifier blend, AB: acidifier blend in absence of fumaric acid and, AF+AB: presence of fumaric acid and acidifier blend. For E2, the pre-starter I diet were used and the same treatments as E1 evaluated. No treatment effects (P>0.05) were observed on performance, diarrhea incidence (E1), gut pH values and duodenum morphometry of piglets (E2). However, the addition of AB increased (P<0.05) large intestine relative weight and, FA addition decreased (P<0.05) pancreas relative weight, jejunum villi height and, total coliform and E. coli counts in cecum. The inclusion of FA and AB in diets containing colistin or halquinol did not improve performance, although FA exerted an inhibitory effect on cecum microbiota.

Macroscopia e topografia do aparelho digestório de emas (Rhea americana americana) / Gross morphology and topography of the digestive apparatus in rheas (Rhea americana americana)

As emas são aves que pertencem ao grupo das ratitas e juntamente com os avestruzes e emus, são as maiores aves vivas na atualidade. Neste trabalho estudou-se os aspectos macroscópicos do aparelho digestório de emas com o intuito de fornecer informações importantes ao estudo dos hábitos alimentares dessas aves, bem como de sua anatomia. Foram utilizados vinte animais jovens com idade entre dois e seis meses obtidos do Centro de Multiplicação de Animais Silvestres (Cemas), registrado com criador científico sob o nº 1478912. Após dissecação verificou-se que a língua era pequena, disposta no assoalho da cavidade oral, possui forma rombóide e estava inserida pela sua base por um frênulo. O esôfago era um tubo retilíneo de aspecto elástico com fibras longitudinais, sem dilatação, o que confere a ausência do papo. O proventrículo gástrico apresentava formato fusiforme. O ventrículo gástrico possuía formato ligeiramente oval, quando repleto, internamente era recoberto por uma cutícula gástrica espessa. O intestino delgado era formado por três regiões distintas: duodeno, jejuno e íleo. O duodeno possuía coloração cinza claro e apresentava-se curvado em forma de "U". O jejuno era longo e formado por várias alças curtas dispostas uma sobre a outra e possuía coloração verde escuro. O íleo era de cor cinza e continuo com o jejuno. Na linha ventral ao reto e cloaca, este se estendia em sentido cranial, dorsalmente ao duodeno ascendente. O intestino grosso era formado por dois cecos, um direito e um esquerdo, e o cólon-reto contínuo com o íleo e a cloaca. As estruturas que compõem o aparelho digestório de ema assemelham-se com o que preconiza a literatura, com relação à forma e topografia para a maioria das aves, contudo os cecos são bem desenvolvidos e bastante dilatados nas emas.

Rheas are birds belonging to the ratites group and, among ostriches and emus, are the largest birds currently alive. In this work we studied the macroscopic aspects of rheas' digestive tract in order to provide important information to a better understanding of these birds' eating habits as well their anatomy. Twenty young animals aging between two and six months from the Centre for Wild Animals Multiplication (Cemas, scientific breeding license form Ibama no.1478912) were used. After dissection it was observed that their tongue was small and presented a rhomboid form, being disposed on the oral cavity floor, and inserted in its base by a frenulum. The esophagus was a rectilinear tube with elastic aspect and longitudinal elastic fibers, without dilation, which gives it an absence of crop. The proventriculus presented a fusiform form and the gastric ventricle showed and slightly oval form when filled, and was internally coated with a thick gastric cuticle. The small intestine was composed of three distinct regions: duodenum, jejunum and ileum. The duodenum had a light gray color and showed a "U" curved shaped. The jejunum was dark green, long and composed of several short loops arranged above each other. The ileum had a gray color and was connected with the jejunum. In ventral line to the rectum and cloaca, the ileum extended cranially, dorsally to the ascending duodenum. The large intestine was composed of two caeca, one right and one left, and colon-rectum and ileum were continuous with the cloaca. The structures of the rhea digestive tract resemble those described in the literature regarding to its shape and topography, even though rhea's caeca are well developed and relatively long.

Morfologia do tubo digestório da tartaruga verde (Chelonia mydas) / Morphology of the digestive tube of the green turtle (Chelonia mydas)

Para avaliar a morfologia do tubo digestório da tartaruga verde (Chelonia mydas) 10 animais, 9 juvenis e 1 adulto, foram analisados. A retirada dos órgãos digestórios procedeu-se após abertura do plastrão. A descrição e a medida do comprimento de cada órgão [esôfago, estômago, intestino delgado (ID) e intestino grosso (IG)] foram realizadas com o tubo digestório aberto. Os resultados mostraram que tanto nos animais juvenis como no adulto, o esôfago foi marcado pela presença de papilas pontiagudas em sua mucosa interna. O estômago apresentou aspecto saculiforme com fundo cego. No ID foi observado pregas reticulares na mucosa duodenal, enquanto o jejuno e do íleo mostrou pregas retilíneas longitudinais. O IG foi marcado pela alternância de regiões abauladas (haustros ou saculações) e estreitamentos. A microscopia do tudo digestório em C. mydas revelou esôfago com mucosa pregueada revestida por epitélio estratificado pavimentoso queratinizado. O estômago mostrou-se dividido em regiões: cárdica, fúndica, pilórica, as quais diferiam quanto ao número de glândulas e disposição da camada muscular. O ID apresentou-se marcado por vilosidades, e o IG por mucosa pregueada contendo glândulas na lâmina própria. A morfologia do tubo digestório da tartaruga verde mostrou-se adaptada ao seu hábito alimentar, possuindo especializações e um longo trato digestório que promove o aumento da superfície de absorção, já que seu alimento é de difícil digestão.

The morphology of the digestive tube of the green turtle (Chelonia mydas) was evaluated. Nine young e 1 adult turtles were analyzed. The digestive organs withdrew occurred after plastron opening. The length's description and measurement from each organ [esophagus, stomach, small intestine (SI) and large intestine (LI)] were made with digestive tube opened. The results showed that in both the adult and young animals, the esophagus from all species were marked by the presence of pointed papillae on internal mucous. The stomach presented saclike shape with blind fund. In the SI, reticular pleats in the duodenal mucous membrane have been observed, while the jejune and the ileum showed rectilinear longitudinal pleats. The LI was marked by the alternation of arched areas (haustra or sacculations) and narrowings. The microscopy of digestive tube from C. mydas revealed esophagus with folded mucous covered by keratinized and stratified squamous epitheliums. The stomach was divided in regions: cardiac, fundic e pyloric which differed as to the number of glands and the muscle layer's arrangement. The SI presented marked by microvillus, and LI by folded mucous with glands the lamina propria. The morphology of the tube digestive of the green turtle showed to be adapted to your eating habits. A long the digestive tract and specializations provide greater area of absorption and more efficiency in digestion in this species.

Migrating motor complex in biological sciences: characterization, animal models and disturbances.

The migrating motor complex (MMC) occurs in most mammals and birds and is organized during the fetal life. In some species, like ruminants and other herbivores, it is not abolished by feeding but its character and controlling mechanisms do not vary considerably from other animal species. However, the mechanisms controlling the MMC are complex and incompletely recognized. The central nervous system exerts rather modulatory effects upon the MMC and the role of the enteric nervous system in the initiation and propagation of the MMC is crucial. The hormones appear mainly to disrupt and convert the MMC cycle into the fed pattern. Several types of the disturbances of the MMC cycle and its phases have been described in various pathophysiological conditions. However, it can be more suitable to identify and describe the given MMC abnormality than to establish the rules of the MMC behavior in the course of the gastrointestinal diseases.

Morphology, histology and histochemistry of the digestive system of South American Catfish (Rhamdia quelen) / Morfología, histología e histoquímica del tubo digestivo del Bagre Sudamericano (Rhamdia quelen)

The purpose of the present work was the anatomical, histo logical and histochemical description oí Rhamdia quelen juvenile digestive system. Samples of gut were fixed, dehydrated and included in paraffin and then stained with haematoxylin and eosin. For the identification and differentiation of mucosubstances the preparations were treated with Periodic Acid Schiff, Alcian Blue pH 0,4 and 2,5 andPAS/AB pH 2,5. Anatomical details of the oesophagus were like a short tube with primary and secondary mucous folds. The stratified epithelium is composed of three cellular types: small cells, abundant goblet cells with acid and neutral mucosubstances (MS) and large acid cells. The stomach is J-shaped and its mucosa presents broad and deep folds in relaxing state. Histologically, the stomach shows three different regions: cardiac, fundic and pyloric region. The luminal surface of the epithelium consists of a layer of secretory columnar cells of neutral MS. Tubuloacinar glands were surrounded by connective and muscular smooth fibers bundle. The intestine extends from the stomach until the anus, and four different sections can be distinguished: ascending, descending, convoluta and terminal straight. It was identified a simple columnar epithelium mainly composed by two cellular types: absorptive cell and goblet cell neutral MS secretory. On the basis of the anatomical and histo logical study carried out, we conclude that R. quelen presents an alimentary canal compatible with species that possess omnivorous nutritious habits.

El propósito del presente trabajo fue realizar las descripciones anatómica, histológica e histoqufmica del sistema digestivo de Rhamdia quelen jóvenes. Las muestras de intestino fueron fijadas, deshidratadas e incluidas en parafina y posteriormente teñidas con hematoxilina y eosina. Para la identificación y diferenciación de muco substancias los preparados fueron tratados con ácido periódico de Schiff, Azul Alcian pH 0,4 y 2,5 y PAS/AB pH 2,5. Los detalles anatómicos del esófago mostraron un pequeño tubo con pliegues mucosos primarios y secundarios. El epitelio estratificado presentaba tres tipos celulares: células pequeñas, abundantes células caliciformes con muco substancia (MS) acida y neutra y células grandes acidas. El estómago tenía forma de J y su mucosa presenta pliegues amplios y profundos en estado de relajación. Histológicamente, el estómago mostraba tres diferentes regiones: cardiaca, fúndica y pilórica. La superficie luminal del epitelio constaba de una capa de células columnares secretoras de MS neutro. Glándulas tubuloacinares estaban rodeadas por tejido conjuntivo y fibras musculares lisas. El intestino se extendía desde el estómago hasta el ano, y cuatro diferentes secciones era posible distinguir: ascendente, descendente, convoluta y terminal recta. Se identificó un epitelio columnar simple, compuesto principalmente por dos tipos celulares: células de absorción y células caliciformes secretoras de MS neutra. Sobre la base de los estudios anatómico e histológico realizados, se concluye que R. quelen presenta un canal alimentario compatible con las especies que poseen hábitos nutritivos omnívoros.

In vitro binding of lipid [olive oil and ghee] with chitosan under the conditions mimicking the gastrointestinal tract

An in vitro binding study of chitosan with lipid was carried out under the conditions mimicking the gastrointestinal tract, with special reference to the pHs of stomach and duodenum. Olive oil and ghee were used to represent lipid components of diet, and chitosan [treated and untreated] was used to bind with the mentioned lipids. The results obtained from this study showed that the treated chitosan gave better binding to lipid [olive oil or ghee] compared with the untreated chitosan. Chitosan [treated or untreated] showed higher affinity towards olive oil than ghee. Incubation period accompanied with shaking also influenced the binding of lipid to chitosan and the maximum binding was attained after 2.5 hrs of incubation. The ratio of chitosan to lipid used was found to affect the amount of lipid bound per gram of chitosan. Olive oil bound per gram of chitosan was 4.6 +/- 0.28 -7.1 +/- 0.14 g while ghee was 3.6 +/- 0.28 - 6.2 +/- 0.28 g under 1:100 experimental ratio of chitosan to lipid, and shaking for 2.5 hrs at physiological temperature of 37°C. Consideration of pKa value suggests that the predominated form of chitosan at duodenal pH [-7.0] is uncharged chitosan, which is precipitated along with the lipid adsorbed onto it

Epidemiologia e desfecho de pacientes cirúrgicos não cardíacos em unidades de terapia intensiva no Brasil / Epidemiology and outcomes of non-cardiac surgical patients in Brazilian intensive care units

OBJETIVO: Devido aos avanços da medicina e ao envelhecimento da população, a proporção de pacientes em risco de morte após cirurgias está aumentando. Nosso objetivo foi avaliar o desfecho e a epidemiologia de cirurgias não cardíacas em pacientes admitidos em unidade de terapia intensiva. MÉTODOS: Estudo prospectivo, observacional, de coorte, realizado em 21 unidades de terapia intensiva. Um total de 885 pacientes adultos, cirúrgicos, consecutivamente admitidos em unidades de terapia intensiva no período de abril a junho de 2006 foi avaliado e destes, 587 foram incluídos. Os critérios de exclusão foram; trauma, cirurgias cardíacas, neurológicas, ginecológicas, obstétricas e paliativas. Os principais desfechos foram complicações pós-cirúrgicas e mortalidade na unidade de terapia intensiva e 90 dias após a cirurgia. RESULTADOS: Cirurgias de grande porte e de urgência foram realizadas em 66,4 por cento e 31,7 por cento, dos pacientes, respectivamente. A taxa de mortalidade na unidade de terapia intensiva foi de 15 por cento, e 38 por cento dos pacientes tiveram complicações no pós-operatório. A complicação mais comum foi infecção ou sepse (24,7 por cento). Isquemia miocárdica foi diagnosticada em apenas 1,9 por cento. Um total de 94 por cento dos pacientes que morreram após a cirurgia tinha co-morbidades associadas (3,4 ± 2,2). A principal causa de óbito foi disfunção de múltiplos órgãos (53 por cento). CONCLUSÃO: Sepse é a causa predominante de morbidade em pacientes submetidos a cirurgias não cardíacas. A grande maioria dos óbitos no pós-operatório ocorreu por disfunção de múltiplos órgãos.

OBJECTIVES: Due to the dramatic medical breakthroughs and an increasingly ageing population, the proportion of patients who are at risk of dying following surgery is increasing over time. The aim of this study was to evaluate the outcomes and the epidemiology of non-cardiac surgical patients admitted to the intensive care unit. METHODS: A multicenter, prospective, observational, cohort study was carried out in 21 intensive care units. A total of 885 adult surgical patients admitted to a participating intensive care unit from April to June 2006 were evaluated and 587 patients were enrolled. Exclusion criteria were trauma, cardiac, neurological, gynecologic, obstetric and palliative surgeries. The main outcome measures were postoperative complications and intensive care unit and 90-day mortality rates. RESULTS: Major and urgent surgeries were performed in 66.4 percent and 31.7 percent of the patients, respectively. The intensive care unit mortality rate was 15 percent, and 38 percent of the patients had postoperative complications. The most common complication was infection or sepsis (24.7 percent). Myocardial ischemia was diagnosed in only 1.9 percent of the patients. A total of 94 percent of the patients who died after surgery had co-morbidities at the time of surgery (3.4 ± 2.2). Multiple organ failure was the main cause of death (53 percent). CONCLUSION: Sepsis is the predominant cause of morbidity in patients undergoing non-cardiac surgery. In this patient population, multiple organ failure prevailed as the most frequent cause of death in the hospital.