Reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, electrophysiological recording, and intraneuronal injection of the neuronal tracer biocytin were integrated in a study of the functional expression of corticotropin-releasing factor (CRF) receptors in the guinea pig enteric nervous system. RT-PCR revealed expression of CRF1 receptor mRNA, but not CRF2, in both myenteric and submucosal plexuses. Immunoreactivity for the CRF1 receptor was distributed widely in the myenteric plexus of the stomach and small and large intestine and in the submucosal plexus of the small and large intestine. CRF1 receptor immunoreactivity was coexpressed with calbindin, choline acetyltransferase, and substance P in the myenteric plexus. In the submucosal plexus, CRF1 receptor immunoreactivity was found in neurons that expressed calbindin, substance P, choline acetyltransferase, or neuropeptide Y. Application of CRF evoked slowly activating depolarizing responses associated with elevated excitability in both myenteric and submucosal neurons. Histological analysis of biocytin-filled neurons revealed that both uniaxonal neurons with S-type electrophysiological behavior and neurons with AH-type electrophysiological behavior and Dogiel II morphology responded to CRF. The CRF-evoked depolarizing responses were suppressed by the CRF1/ CRF2 receptor antagonist astressin and the selective CRF1 receptor antagonist NBI27914 and were unaffected by the selective CRF 2 receptor antagonist antisauvagine-30. The findings support the hypothesis that the CRF1 receptor mediates the excitatory actions of CRF on neurons in the enteric nervous system. Actions on enteric neurons might underlie the neural mechanisms by which stress-related release of CRF in the periphery alters intestinal propulsive motor function, mucosal secretion, and barrier functions.

The gastrointestinal (GI) tract is a diverse habitat for multiple microorganisms. Disturbances in the microbiome of the GI tract have been associated with psychiatric disorders including autism spectrum disorder (ASD). Individuals with ASD, when compared to neurotypical individuals, have demonstrated differing gut species. Also, it has been shown that microbial transplant therapies impact ASD symptoms in patients. Animal models of behaviors associated with ASD might offer insight into the actual role these microbial differences may occupy regarding symptoms. Unfortunately, ASD does not have an accepted animal model where the GI alterations have been thoroughly explored. In this study, we sought to determine if the microbiome and other GI alterations were observed in two potential mouse models of social behavior deficits, the genetic BTBR T+Itpr3tf/J (BTBR) mouse strain and an environmental mouse strain consisting of offspring of valproic acid (VA) treated pregnant controls. Both mouse models have been shown to exhibit social and repetitive behaviors that are found in human ASD. Using the Illumina MiSeq, we were able to identify taxonomy associated with 16S ribosomal DNA sequences extracted from fecal matter. We were able to compare the sequencing results from the two affected strains and a control C5BL/6J mouse strain for both female and male animals using the Qiagen CLC Genomics Workbench software. Overall, microbiome composition was found to be significantly different between the male control animals (N=13) when compared to the VA (N=14; p-value=.00003) or the BTBR (N=15; p-value=.0001) males using a PERMANOVA analysis. This was replicated in female groups where composition significantly differed between the control (N=14) and VA (N=14; p-value=.00003) or BTBR (N=14; p-value=.00001) females. Additionally, short-chain fatty acid analysis using gas capillary-based chromatography was used to examine acetate, butyrate, propionate, and valerate levels in feces. Only valerate levels were significantly lower (p

The gastrointestinal tract has a large functional reserve. This is particularly true of the small intestine, and early studies by Flint in 1912, showed that dogs could withstand 50%-70% small intestinal resection, returning to normal health after an initial period of weight loss and malabsorption. No doubt, this reserve is in part due to the very high rate of epithelial proliferation in small bowel mucosa. Intestinal adaptation is the result of morphological and functional changes, and while these parameters can be accurately appreciated, the mechanisms by which these changes take place, are still under active investigation. This section summarises the changes, both structural and functional, in the adaptive process, and this is followed by a review of the background work done on the possible mechanism of adaptation. The normal anatomy of intestinal mucosa is however, considered first. Most of the work done to date in the field of intestinal adaptation, involves the small bowel, and this part of the gut will be discussed predominantly, but data available on colonic growth will be mentioned.

Introducción: El SII se caracteriza por la presencia de dolor abdominal, diarrea, estreñimiento, o la alternancia de ambas, la causa de esta patología tiene que ver con muchos factores: alimentación, antecedentes de enfermedades, estilo de vida, etc. En el Hospital Guillermo Almenara Irigoyen (HGAI), se desconoce la prevalencia del SII. Objetivos: Determinar la prevalencia del SII en la consulta ambulatoria del servicio de Gastroenterología del HGAI, así como también describir los subtipos de SII que se presentan. Material y Métodos: El presente estudio es de tipo descriptivo y de corte transversal. La muestra consta de 1365 pacientes, se utilizo el muestreo por conveniencia. Se confecciono una encuesta ad hoc, con dos partes: una ficha de recolección de datos (clínicos y sociodemográficos) y otra con los criterios de ROMA II para el diagnostico de SII. Los pacientes fueron encuestados en la sala de espera de los dos (02) consultorios ambulatorios del Servicio de Gastroenterología (SG) del HGAI, del 06 de Abril del 2003 al 06 de Junio del 2003. Se realizo el análisis estadístico con el programa SPSS v11, para la descripción de los resultados. Resultados: La prevalencia del SII en el SG del HGAI fue de 38.8%. De los pacientes con SII de acuerdo a los criterios de Roma II tenemos; el 44% presento SII tipo diarrea, el 32% fue tipo estreñimiento, el 19% fue tipo mixto y el 5% no se pudo determinar. De la prevalencia general de 38.8 %, el sexo femenino aportó una prevalencia del 26.5%, y el sexo masculino aporto una prevalencia del 12.2 %. La variable Sexo fue significativa, por lo que la probabilidad de que el diagnostico de SII se relaciona mas con el sexo femenino. Por lo que existiría un riesgo de 1.8 veces en el sexo femenino de tener el SII en relación al sexo masculino. El grupo etareo de 60 a 69 años es el que presenta la mayor prevalencia en el diagnostico de SII (10.2%). El grupo de edad de 50 años hacia delante presenta una prevalencia acumulada de 28.8%. Asimismo se encontraron hallazgos secundarios con las variables que tuvieron significancia estadística las cuales fueron: Sexo, Grupo etareo, Diabetes Mellitus (DM), Antecedente de Cirugía Pélvica y Antecedente personal de Cáncer gastrointestinal. Conclusión: Existe una alta prevalencia del SII (38.8%) en la población estudiada, siendo el SII de tipo Diarrea el más frecuente. El grupo de edad de 50 años hacia delante presenta una prevalencia acumulada de 28.8%. / Tesis de segunda especialidad

Indiana University-Purdue University Indianapolis (IUPUI) / Chlamydia is the most frequently reported bacterial sexually transmitted infection in the world. Most urogenital chlamydia infections in men and women are asymptomatic, but these infections can lead to irreparable damage in the reproductive system and other tissues. Apart from the urogenital chlamydial infections, we know that chlamydia infects the gastrointestinal tract (GIT) in humans and can colonize the GIT for extended intervals without eliciting pathology. We are interested in investigating tissue tropism determinants in Chlamydia spp. because these could be targeted to development live-attenuated vaccines. Recently, we generated mutagenized isolates of the mouse pathogen Chlamydia muridarum, a close relative of the human pathogen Chlamydia trachomatis which causes chlamydia. One mutant that we isolated is significantly attenuated in murine gastrointestinal tissues compared to wild type, but retains its pathogenicity in the murine urogenital tract. Using novel genetic techniques, whole-genome sequencing, and complementation using newly developed vector systems we identified a chromosomal factor, tc0600, that we believe mediates the altered tissue tropism phenotype of this mutant in mice. Notably, the Chlamydia trachomatis ortholog of tc0600 has been linked to chlamydial GIT tropism in humans.

Human gastrointestinal tract is complex and highly dynamic environment, harboring trillions of microbes that collectively play a pivotal role in host metabolism, immune function, and the maintenance of general health. However, studying the gut microbes and their interplay with host requires measurements at multiple dimensions is challenging since we currently lack the tools to directly measure these microorganisms at many different levels, which hinders our ability to unravel the ecology of gut microbes and their mechanistic underpinnings in human health and disease. Here, I present a set of novel techniques to study gut microbe and host-microbe interactions at unprecedented resolution, providing tremendous innovative insights to comprehensively understand the gut microbes and their environment. First, I leverage a high-throughput automation system to build a machine learning guided culturomics platform, enabling rapid isolation and culturing of personalized gut strains. Second, to better characterize the functions of these non-model microorganisms, I describe a ribonuclease-based ribosomal RNA depletion approach for microbe, paving the way for high-throughput bacterial transcriptome profiling. Next, shifting from gut microbes to the interaction with the host, I develop a technique of fecal exfoliome sequencing to robustly profile host gastrointestinal transcriptome in a non-invasive way, providing a powerful approach to study the temporal behaviors of gut cells in health and disease. Finally, to study massive genetic variants in microbiome arena, I describe a template-mediated synthesis approach for rapid and efficient generation of genetic variants sequences and demonstrate its utility in a few cases. Taken together, these techniques provide in-depth novel measurements into the ecology and physiology of human gut microbes, collectively making up an exciting set of tools for future studies.

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Controlling pathogenic presence in broilers has become a priority in the poultry industry to prevent economic losses due to disease and infection, as well as the possible contamination of chicken products. The use of antibiotics reduces the incidence of infections; however, their removal from production initiated the search for suitable alternatives. Probiotic ineed supplements have been widely evaluated as alternatives. Probiotic use has improved broiler performance, reduced pathogenic loads, and stimulated the immune system at later life stages. However, there is still a gap in protection during the first weeks after the chick hatches. The in ovo supplementation of probiotics has the potential of promoting early health benefits and protect the chick against pathogens after hatch. In the present study, the in ovo inoculation of different probiotic species was evaluated. It was determined that the inoculation of higher concentrations of E. faecium (107 cfu/50µL) into the egg improves growth performance and intestinal morphology compared to lower doses (105 and 106 cfu/50µL). It was also determined that not all B. subtilis serotypes are safe for in ovo inoculation, even if recognized as safe for use in feed, due to a high reduction in hatchability. However, certain B. subtilis are safe for in ovo inoculation and regulate the gut microflora through modulations in coliforms and aerobic bacteria after hatch. Lastly, the in ovo inoculation of different Lactobacillus strains does not affect hatchability or growth performance. However, different Lactobacillus species stimulated cytokine production even during the first week of hatch. The bursa of Fabricius morphology was modulated through an increase in follicular area, which could possibly induce higher antibody production against incoming pathogenic challenges. These results indicate that the in ovo inoculation of probiotic bacteria can induce earlier benefits to broiler health through early changes in gut microflora, as well as early stimulation in the immune system. The early protection provided through the in ovo inoculation of probiotics combined with the protection obtained through the administration of probiotics in feed could potentially result in overall healthier broilers and therefore improved performance.