Rol de la microbiota gastrointestinal en la regulación de la respuesta inmune / The role of gut microbiota in the regulation of the immune response

The gastrointestinal tract hosts around 10(14) bacterial microorganisms, in a constantly growing density from the stomach to the distal colon. This microbiota is composed by more than 500 species of bacteria, which are quickly acquired after birth, fairly stable during the host’s life, and essential for human homeostasis. These bacteria have important functions, such as stimulating the immune system, protecting the host from invading bacteria and viruses, and improving digestion, especially of complex carbohydrates. Also, the gut microbiota interacts directly with the immune system. However, the interaction of the intestinal epithelium and its microbiota with the immune system has yet to be fully understood. Secretory immunoglobulin A, produced by the plasma cells in Peyer’s patches and in the lamina propria, maintains non-invasive commensal bacteria and neutralize invasive pathogens. Dendritic cells migrate from the lamina propria of the secondary lymphoid organs to regulate gut immunity. They also have a key role maintaining luminal IgA and inducing the growth of regulatory T cells. Dendritic cells supervise the gut microenvironment too, keeping an immunological equilibrium and tolerance. The importance of the gut microbiota in regulating the immune system lies mostly in the homeostasis-or positive equilibrium. Thus, many diseases are a consequence of poor interactions or a loss of this equilibrium.

Prevalencia de vaginosis bacteriana en trabajadoras sexuales chilenas / Prevalence of bacterial vaginosis in Chilean sex workers

OBJETIVO: Determinar la prevalencia de vaginosis bacteriana (VB) en trabajadoras sexuales chilenas y relacionar los hallazgos con variables sociodemográficas, sexuales y clínicas. MÉTODO: Se estudió una muestra de 379 trabajadoras sexuales que asistían para control a Unidades de Atención y Control de Salud Sexual de Chile. A todas se las entrevistó para obtener antecedentes sociodemográficos y sexuales, se les realizó evaluación clínica que incluyó características del flujo vaginal, pH y prueba de aminas, y se les tomó una muestra vaginal para tinción de Gram. Para el diagnóstico de VB se empleó el criterio de Nugent. Los datos fueron analizados con EPI-INFO 3.4.1 y BioStat, utilizándose un grado de significación de P < 0,005. RESULTADOS: La prevalencia de VB fue de 69,1 por ciento. El síndrome no se asoció a las variables sociodemográficas edad y escolaridad. Las mujeres que vivían (casadas o no) con su pareja tuvieron menos frecuencia de VB en comparación con las mujeres solteras (P < 0,001). No hubo variables sexuales asociadas a VB, en tanto que el empleo del dispositivo intrauterino (DIU) sí lo estuvo (P < 0,0001). La presencia de descarga vaginal, pH vaginal alterado y prueba de aminas positiva se asociaron a la infección (P < 0,0001). CONCLUSIONES: En coincidencia con otros estudios realizados distintos países, el presente trabajo observó que las trabajadoras sexuales chilenas tienen una alta prevalencia de VB, con mayor riesgo para aquellas que usan DIU como método de anticoncepción o que no conviven (casadas o no) con su pareja.

OBJECTIVE: To determine the prevalence of bacterial vaginosis (BV) in Chilean sex workers and relate the findings to sociodemographic, sexual, and clinical variables. METHODS: A sample of 379 sex workers seen in Chilean Sexual Health Monitoring and Care Units for check-ups was studied. All of them were interviewed to obtain their sociodemographic and sexual history. A clinical examination was performed that included the characteristics of vaginal discharge, pH, and amine test. A vaginal sample was taken for Gram stain. The Nugent criteria were used for the diagnosis of BV. The data was analyzed with EPI-INFO 3.4.1 and BioStat, using a degree of significance of P < 0.005. RESULTS: BV prevalence was 69.1 percent. The syndrome was not associated with the sociodemographic variables, age or education. BV was less common in women (married or unmarried) who lived with their partners than in single women (P < 0.001). There were no sexual variables associated with BV, whereas use of intrauterine devices was related (P < 0.0001). The presence of vaginal discharge, abnormal vaginal pH, and positive amine test were associated with infection (P < 0.0001). CONCLUSIONS: Like other studies conducted in different countries, this study observed that Chilean sex workers have a high prevalence of BV, with greater risk for women who use IUDs for birth control or women (married or unmarried) who do not live with their partners.