The impact of small intestinal bacterial overgrowth on the growth of children and adolescents / Impacto do sobrecrescimento bacteriano no intestino delgado sobre o peso e a estatura de crianças e adolescentes

ABSTRACT Objective: To evaluate the association between small intestinal bacterial overgrowth (SIBO) and weight and height impairment in children and adolescents with gastroenterology diseases. Methods: Observational and retrospective study. All 162 patients aged less than 19 years old who underwent breath test in search of SIBO between 2011 and 2016 were studied. Breath test was collected after the intake of 10 grams of lactulose. The concentration of hydrogen and methane was measured for 180 minutes after the beginning of the test by 12i QuinTronMicroLyzer device. Results: SIBO was identified in 51 (31.5%) patients. There was no difference between the age of those with (mean=8.7y.o; 25th and 75th percentile: 4.6 and 11.3) and without (mean=7.9y.o 25th and 75th percentile: 4.8 and 12.2) SIBO (p=0.910). There was no association between gender and SIBO (male 26.3% vs. female 36.3%, p=1.00). A lower median of height-for-age Z score (mean=-1.32; 25th and 75th percentile: -2.12 and -0.08 vs. mean=-0.59; 25th and 75th percentile: -1.57 and 0.22; p=0.04) was demonstrated in children with SIBO when compared with children without it. There was no difference between the BMI-for-age Z score of patients with (mean=-0.48) and without SIBO (mean=-0.06) (p=0.106). The BMI of patients with SIBO (median=15.39) was lower than of those without it (median=16.06); however, the statistical analysis was not significant (p=0.052). The weight-for-age Z score was lower in patients with SIBO (mean=-0.96) than in those without SIBO (mean=-0.22) (p=0.02) Conclusions: Children and adolescents with SBIO associated with diseases of the gastrointestinal tract have lower weight and height values.

RESUMO Objetivo: Avaliar a existência de associação entre sobrecrescimento bacteriano no intestino delgado (SBID) e comprometimento de peso e estatura em crianças e adolescentes com doenças do aparelho digestivo. Métodos: Estudo observacional e retrospectivo em ambulatório de gastroenterologia pediátrica. Foram incluídos todos os 162 pacientes com idade inferior a 19 anos que realizaram teste respiratório para pesquisa de SBID entre 2011 e 2016. O teste respiratório foi realizado após ingestão de dez gramas de lactulose. Foram determinadas as concentrações de hidrogênio e metano em aparelho 12i QuinTron MicroLyzer até 180 minutos após o início do teste respiratório. Resultados: SBID foi caracterizado em 51 (31,5%) dos 162 pacientes. Não houve diferença na idade das crianças com (mediana=8,7 anos; percentil 25-75: 4,6-11,3) e sem (mediana=7,9 anos; percentil 25-75: 4,8-12,2) SBID (p=0,910). Não se observou associação entre SBID e sexo (masculino 27,4% e feminino 36,6%; p=0,283). O escore Z da estatura-idade nos pacientes com SBID (mediana=-1,32; percentil 25-75: -2,12—0,08) foi menor (p=0,040) do que naqueles sem SBID (mediana=-0,59; percentil 25-75: -1,57-0,22). Na comparação do escore Z de índice de massa corpórea-idade não foi observada diferença entre os grupos com (média=-0,489±1,528) e sem (média=-0,067±1,532) SBID (p=0,106). Nos pacientes com menos de 10 anos de idade, o escore Z de peso-idade foi menor nos pacientes com SBID (média=-0,968±1,359) do que nos sem SBID (média=-0,223±1,584) (p=0,026). Conclusões: Crianças e adolescentes com SBID associado a doenças do trato gastrintestinal apresentam menores valores de peso e estatura.

Preferential usage of rifaximin for the treatment of hydrogen-positive small intestinal bacterial overgrowth / Rifaximina como tratamiento de elección en pacientes con sobrecrecimiento bacteriano con prueba de hidrógeno positiva

Objectives: Small intestinal bacterial overgrowth (SIBO) is challenging to treat and diagnose and is associated with diagnosis of irritable bowel syndrome (IBS). Although no FDA-approved medications exist for treatment of SIBO, rifaximin has recently received approval to treat diarrhea-predominant IBS and patients with methane-positive SIBO breath tests. The aim of this study is to evaluate patient response to rifaximin for SIBO based on breath test results. Materials and methods: All patients underwent breath testing to evaluate for SIBO during a 42-month period. Patients were defined as having a positive glucose breath test for SIBO based on an increase of ≥ 20 ppm of hydrogen and/or ≥ 10 ppm of methane 90 minutes after ingesting glucose. Patient demographic and symptom data, antibiotic treatment regimens, symptomatic response to therapy, and repeat treatments were recorded. Institutional review board approval was obtained. Results: A total of 53 of 443 patients had positive breath testing for SIBO. Response rates to rifaximin (550 mg three times daily for 14 days) were 47.4% for hydrogen positivity alone and 80% for both hydrogen and methane positivity. Conclusions: Rifaximin was the most commonly prescribed antibiotic regimen for SIBO therapy. Patients with hydrogen or hydrogen and methane positive breath tests responded well to rifaximin therapy. For patients with hydrogen-positive SIBO, rifaximin may prove a highly effective therapy in providing symptom relief from the effects of SIBO.

Objetivos: El sobrecrecimiento bacteriano de intestino delgado es una entidad difícil de diagnosticar y tratar, frecuentemente asociada con el síndrome de intestino irritable. A pesar que la FDA no ha aprobado medicamentos para tratar el sobrecrecimiento bacteriano, la rifaximina ha sido recientemente aprobada para tratar el intestino irritable tipo diarrea y en pacientes con test de aliento metano positivo en sobrecrecimiento bacteriano. El objetivo del estudio fue evaluar la respuesta a rifaximina de los pacientes con sobrecremiento bacteriano con prueba de aliento positiva. Material y métodos: Todos los pacientes que se realizaron prueba de aliento por sobrecrecimiento bacteriano durante un periodo de 42 meses. Se definió un paciente con sobrecrecimiento bacteriano positivo si tenía un incremento mayor a 20 ppm de hidrógeno y/o 10 ppm de metano luego de 90 minutos de la ingesta de glucosa. Se registraron los datos demográficos, síntomas, tratamiento antibióticos recibidos, respuesta a la terapia, y repetición de tratamientos. Resultados: Un total de 53 de 443 pacientes tuvieron prueba de aliento positiva para sobrecrecimiento bacteriano. La tasa de respuesta a rifaximina (550 mg tres veces x día x 14 días) fue 47.4% para pacientes con sólo test de hidrógeno positivo, y 80% para pacientes con tanto test de hidrógeno como metano positivos. Conclusiones: La rifaximina es el régimen antibiótico más frecuentemente utilizado en sobrecrecimiento bacteriano. Los pacientes con prueba de aliento de hidrógeno o hidrógeno y metano positivos respondieron bien a la rifaximina. Para pacientes con sobrecrecimiento bacteriano prueba de hidrógeno positiva, la rifaximina puede ser una terapia efectiva en mejorar síntomas.

Comparación del incremento del perímetro abdominal con la prueba de hidrógeno espirado como predictor clínico de intolerancia a la lactosa / Comparison of an increased waist circumference with a positive hydrogen breath test as a clinical predictor of lactose intolerance

Introducción. La intolerancia a la lactosa es una afección frecuente en pediatría, cuyo diagnóstico erróneo conlleva morbilidad. El objetivo primario del estudio fue evaluar la utilidad del incremento del perímetro abdominal durante la prueba de hidrógeno espirado como predictor de intolerancia a la lactosa. El objetivo secundario fue analizar la influencia del índice de masa corporal, de la medida de la cintura y de la edad en la distensión abdominal de pacientes intolerantes a la lactosa. Población y métodos. Se incluyó a 138 sujetos de entre 3 y 15 años de edad a los cuales se les realizaron mediciones seriadas del perímetro abdominal y determinaciones de hidrógeno espirado cada 30 minutos por 3 horas, durante la prueba de hidrógeno espirado. Resultados. Del total de la muestra, 35 (25,4%) resultaron intolerantes a la lactosa. El incremento de 0,85 cm en el perímetro abdominal comparado con el perímetro abdominal basal tiene sensibilidad del 88% y especificidad del 85% para predecir intolerancia a la lactosa (OR 42,14; IC 95%: 13,08-135,75; p <0,001). El índice de masa corporal y la medida de la cintura no afectaron la distensibilidad del abdomen (p= NS); sin embargo, la edad modificó el momento de la distensión. Conclusiones. El incremento del perímetro abdominal de 0,85 cm en relación con el perímetro abdominal basal durante la prueba de hidrógeno espirado es un parámetro útil para diagnosticar la intolerancia a la lactosa en pediatría. Las variaciones en relación con el índice de masa corporal y la cintura no modificaron la utilidad del incremento del perímetro abdominal a diferencia de la edad.

Introduction. Lactose intolerance is a common disease in pediatrics, and its wrong diagnosis will lead to morbidity. The primary objective of this study was to assess the usefulness of an increased waist circumference during the hydrogen breath test as a predictor of lactose intolerance. The secondary objective was to analyze the impact of body mass index, waist circumference measurement, and age on the abdominal distension of patients with lactose intolerance. Population and methods. A total of 138 subjects aged 3 to 15 years were included. They underwent serial measurements of the waist circumference and hydrogen levels in the breath every 30 minutes over 3 hours during the hydrogen breath test. Results. Out of the entire sample, 35 (25.4%) patients had lactose intolerance. An increase of 0.85 cm in waist circumference compared to the baseline waist circumference results in a sensitivity of 88% and a specificity of 85% to predict lactose intolerance (odds ratio: 42.14, 95% confidence interval: 13.08-135.75, p < 0.001). The body mass index and waist circumference measurement did not affect abdominal distension (p= not significant); however, age modified the time of distension. Conclusions. A 0.85 cm increase in waist circumference compared to the baseline waist circumference during the hydrogen breath test is a useful parameter for the diagnosis of lactose intolerance in pediatrics. Variations in relation to body mass index and waist circumference did not affect the usefulness of an increased waist circumference, unlike age.

Oral administration of exogenous lactase in tablets for patients diagnosed with lactose intolerance due to primary hypolactasia / Administração oral de lactase exógena em comprimidos em pacientes portadores de intolerância à lactose devido à hipolactasia primária

ABSTRACT Background Primary hypolactasia is a common condition where a reduced lactase activity in the intestinal mucosa is present. The presence of abdominal symptoms due to poor absorption of lactose, which are present in some cases, is a characteristic of lactose intolerance. , Objective Evaluate the efficacy of a product containing exogenous lactase in tablet form compared to a reference product with proven effectiveness in patients with lactose intolerance. Methods Multicentre, randomized, parallel group, single-blind, comparative non-inferiority study. One hundred twenty-nine (129) adult lactose intolerance patients with hydrogen breath test results consistent with a diagnosis of hypolactasia were randomly assigned to receive the experimental product (Perlatte(r) - Eurofarma Laboratórios S.A.) or the reference product (Lactaid(r) - McNeilNutritionals, USA) orally (one tablet, three times per day) for 42 consecutive days. Results Data from 128 patients who actually received the studied treatments were analysed (66 were treated with the experimental product and 62 with the reference product). The two groups presented with similar baseline clinical and demographic data. Mean exhaled hydrogen concentration tested at 90 minutes after the last treatment (Day 42) was significantly lower in the experimental product treated group (17±18 ppm versus 34±47 ppm) in the per protocol population. The difference between the means of the two groups was -17 ppm (95% confidence interval [95% CI]: -31.03; -3.17). The upper limit of the 95% CI did not exceed the a priori non-inferiority limit (7.5 ppm). Secondary efficacy analyses confirmed that the treatments were similar (per protocol and intention to treat population). The tolerability was excellent in both groups, and there were no reports of serious adverse events related to the study treatment. Conclusion The experimental product was non-inferior to the reference product, indicating that it was an effective replacement therapy for endogenous lactase in lactose intolerance patients.

RESUMO Contexto A hipolactasia primária é uma condição muito frequente na qual há redução da atividade da lactase na mucosa intestinal.A presença de sintomas abdominais devidos à má absorção da lactose presente em alguns casos caracteriza a intolerância à lactose. Objetivo Avaliar a eficácia de um produto contendo lactase exógena em comprimidos comparativamente a de um produto comparador com eficácia comprovada em pacientes portadores de intolerância à lactose. Métodos Estudo multicêntrico, randomizado, de grupos paralelos, com investigador cego, comparativo de não-inferioridade. Cento e vinte e nove (129) pacientes adultos portadores de intolerância à lactose e teste do hidrogênio no ar expirado compatível com o diagnóstico de hipolactasia foram randomizados para receber o produto experimental (Perlatte(r) - Eurofarma Laboratórios S.A.) ou o produto comparador (Lactaid(r) - McNeil Nutritionals, EUA), por via oral (um comprimido, três vezes ao dia), durante 42 dias consecutivos. Resultados Os dados dos 128 pacientes que efetivamente receberam o tratamento do estudo foram avaliados (66 tratados com o produto experimental e 62 com o produto comparador). Os dois grupos se mostraram homogêneos quanto aos dados demográficos e clínicos basais. A média da concentração do hidrogênio expirado aos 90 minutos no teste realizado ao final do tratamento (Dia 42) foi significativamente menor no grupo tratado com o produto experimental (17±18 ppm versus 34±47 ppm na população por protocolo). A diferença entre as médias dos dois grupos foi de -17 ppm (intervalo de confiança de 95% [IC95%]: -31,03; -3,17). O limite superior do IC95% não ultrapassou a margem de não-inferioridade estipulada a priori (7,5 ppm). As análises secundárias de eficácia confirmaram a semelhança entre os tratamentos (populações por protocolo e com intenção de tratamento). A tolerabilidade foi excelente em ambos os grupos e não houve relato de eventos adversos graves relacionados ao produto. Conclusão O produto experimental se mostrou não-inferior ao produto comparador, indicando sua eficácia no tratamento substitutivo da lactase endógena em pacientes portadores de intolerância à lactose.

Análisis de test de aire espirado en niños con sospecha de intolerancia a la lactosa / Breath tests in children with suspected lactose intolerance

Introducción: Un 70% de la población general presenta intolerancia a la lactosa; sin embargo, no existen estudios epidemiológicos en la población pediátrica chilena afectada por esta condición. Objetivos: Caracterizar una serie clínica de niños que acude a realizarse el test de aire espirado con lactosa para estudio de intolerancia a la lactosa, determinando la frecuencia de intolerancia y malabsorción, síntomas más frecuentes y rendimiento del test dependiendo de su origen. Pacientes y Método: Pacientes menores de 18 años que acudieron a realizarse el test de aire espirado con lactosa al Laboratorio de Gastroenterología de la Pontificia Universidad Católica de Chile, por sospecha clínica de intolerancia a la lactosa. Se consideró malabsorción un aumento ≥ 20 ppm sobre el nivel basal de hidrógeno (H2) o ≥ 34 ppm de H2 y metano (CH4) en conjunto y como intolerancia cuando lo anterior se asoció a la sumatoria de intensidad de síntomas ≥ 7 en el registro. Resultados: Se analizaron 194 pacientes entre 1 y 17 años de edad. De ellos, 102 (53%) pacientes resultaron malabsorbedores y 53 (27%) intolerantes. La frecuencia de intolerancia a la lactosa varió de un 7,1 a un 45,4%, con una mayor frecuencia a edades mayores. Los síntomas más reportados fueron dolor abdominal, meteorismo y borborigmo. Discusión: La malabsorción e intolerancia a lactosa se pueden pesquisar desde los primeros años de vida utilizando el test de aire espirado con lactosa asociado al cuestionario simultáneo de síntomas. Se puede observar un aumento en la frecuencia de intolerancia con la edad, además de una mayor positividad del examen si es solicitado por un gastroenterólogo.

Introduction: Up to 70% of the world population is lactose intolerance. However, there are no epidemiological studies among Chilean pediatric population affected by this condition. Objectives: Clinical characterization of a series of children who underwent the lactose intolerance breath test for lactose intolerance study, establishing intolerance and malabsorption frequencies, the most frequent symptoms, and test performance depending on the origin. Patients and Methods: Patients under 18 years old who took the lactose intolerance breath test in the Gastroenterology Laboratory of the Catholic University of Chile, and who were admitted due to clinically suspected lactose intolerance. Malabsorption was considered when there was as an increase of ≥ 20 ppm above the baseline (H2) or ≥ 34 ppm of H2 and methane (CH4) combined. Intolerance was considered when the above was associated with a symptom intensity score ≥ 7 during registration. Results: The analysis included194 patients aged 1 to17 years of age. Of these, 102 (53%) presented with malabsorption, and 53 (27%) were intolerant. The frequency of lactose intolerance varied from 7.1 to 45.4%, and it occurred more frequently at older ages. The most common reported symptoms were abdominal pain, bloating and rumbling. Discussion: Lactose malabsorption and intolerance can be investigated from the first years of life using the lactose breath test plus a symptom questionnaire. An increase in the frequency of intolerance with age, and a greater number of positive tests, if they were requested by a gastroenterologist, were observed.

Feasibility of biohydrogen production from industrial wastes using defined microbial co-culture

BACKGROUND: The development of clean or novel alternative energy has become a global trend that will shape the future of energy. In the present study, 3 microbial strains with different oxygen requirements, including Clostridium acetobutylicum ATCC 824, Enterobacter cloacae ATCC 13047 and Kluyveromyces marxianus 15D, were used to construct a hydrogen production system that was composed of a mixed aerobic-facultative anaerobic-anaerobic consortium. The effects of metal ions, organic acids and carbohydrate substrates on this system were analyzed and compared using electrochemical and kinetic assays. It was then tested using small-scale experiments to evaluate its ability to convert starch in 5 L of organic wastewater into hydrogen. For the one-step biohydrogen production experiment, H1 medium (nutrient broth and potato dextrose broth) was mixed directly with GAM broth to generate H2 medium (H1 medium and GAM broth). Finally, Clostridium acetobutylicum ATCC 824, Enterobacter cloacae ATCC 13047 and Kluyveromyces marxianus 15D of three species microbial co-culture to produce hydrogen under anaerobic conditions. For the two-step biohydrogen production experiment, the H1 medium, after cultured the microbial strains Enterobacter cloacae ATCC 13047 and Kluyveromyces marxianus 15D, was centrifuged to remove the microbial cells and then mixed with GAM broth (H2 medium). Afterward, the bacterial strain Clostridium acetobutylicum ATCC 824 was inoculated into the H2 medium to produce hydrogen by anaerobic fermentation. RESULTS: The experimental results demonstrated that the optimum conditions for the small-scale fermentative hydrogen production system were at pH 7.0, 35°C, a mixed medium, including H1 medium and H2 medium with 0.50 mol/L ferrous chloride, 0.50 mol/L magnesium sulfate, 0.50 mol/L potassium chloride, 1% w/v citric acid, 5% w/v fructose and 5% w/v glucose. The overall hydrogen production efficiency in the shake flask fermentation group was 33.7 mL/h-1.L-1, and those the two-step and the one-step processes of the small-scale fermentative hydrogen production system were 41.2 mLVh-1.L-1 and 35.1 mL/h-1.L-1, respectively. CONCLUSION: Therefore, the results indicate that the hydrogen production efficiency of the two-step process is higher than that of the one-step process.

Equilíbrio ácido-básico de embriões e pintos de corte em momentos críticos da incubação e submetidos a diferentes períodos de transferência para o nascedouro / Acid-base balance of embryos and broiler chicks in critical moments of incubation and submitted to different periods of transfer to the hatcher

Foram analisados os níveis de pCO2, pO2, pH e HCO3 - de embriões e pintos de corte provenientes de matrizes novas e velhas, nos momentos anteriores à bicagem interna e externa da casca e ao nascimento, submetidos a diferentes períodos de transferência para as condições ambientais dos nascedouros. Os tratamentos foram definidos pela idade da matriz (33 e 63 semanas) e pela transferência para o nascedouro (aos 15, 17 e 19 dias). O delineamento experimental foi em parcelas subdivididas, sendo a parcela os três momentos de transferência e a subparcela as duas idades das matrizes. Foram utilizadas seis repetições para cada tratamento, e o embrião ou o pinto foi considerado uma repetição. Os dados normais e homogêneos foram submetidos às análises de variância, e as médias comparadas pelos testes F, de Tukey e SNK. Embriões cujos ovos foram transferidos aos 15 dias para o nascedouro apresentaram melhor equilíbrio ácido-básico durante as fases pré-natal e perinatal. Durante o último terço da incubação, independentemente das diferentes condições ambientais às quais os embriões são submetidos e da idade da matriz, há capacidade de resposta fisiológica que permite uma estabilidade no equilíbrio ácido-básico dos pintos após a eclosão...

We analyzed the levels of pCO2, pO2, pH and HCO3 - in embryos and chicks from young and older breeders, in the moments before internal pipping, external pipping and at hatch and submitted to different periods in the environmental conditions of hatchers. The treatments were defined by breeder age (33 and 63 weeks) and transfer to the hatcher (at 15, 17 and 19 days). The experimental design was split plots with three periods in the hatcher and the plots were the two breeder ages. We used six replicates per treatment and the embryo or chick was considered a repetition. The normal data forms were submitted to analysis of variance and means were compared by F, Tukey and SNK tests. Embryos transferred at 15 days to the hatcher had better acid-base balance during the pre-and perinatal phases. During the last third of incubation, regardless of the different environmental conditions which the embryos are subjected and breeder age, there is physiological responsiveness that allows for stability in acid-base balance of the chicks after hatching...

Sobrecrecimiento bacteriano intestinal y pseudoobstrucción intestinal crónica: una relación poco conocida / Small intestinal bacterial overgrowth and chronic intestinal pseudo-obstruction

Chronic intestinal pseudo-obstruction (CIP) is the most severe intestinal motility disorder. Small intestinal bacterial overgrowth (SIBO) is frequently associated to dysmotility. In spite of this association, there is scare data on the relation between CIP and SIBO. To establish occurrence of CIP in SIBO patients in inter-crisis periods. To compare clinical and manometric characteristics of SIBO and non-SIBO patients. Retrospective analysis of 40 CIP patients (average age: 41 years; range: 18-76 years; 75 percent women). The following elements were registered: symptoms (such as pain, distention, vomit, constipation, diarrhea and weight loss); findings of the intestinal manometry (neuropathic, miopatic and mix pattern; intestinal motility index); and SIBO using lactulose H2 breath test, defined as an increase > 20 ppm in 2 or more figures in the first 60 minutes. Statistical analysis: t-test y and comparison of two ratios. SIBO was observed in 60 percent of the patients with CIP. Three or more symptoms were observed in 70.8 percent of the patients with SIBO 50 percentwithout SIBO (p = NS). In patients with SIBO, the most frequent symptom was abdominal pain (70.8 percent p= 0.032). There were no differences between SIBO patients and the different motility patterns, however, the intestinal motility index was lower for the SIBO group (9.7 +/- 44 12.3 +/-7; p < 0.001). : There is a high prevalence of SIBO in CIP patients. This is associated to a major compromise of intestinal motility assessed by the intestinal motility index...

Introducción: La pseudoobstrucción intestinal crónica (POIC) es el trastorno más grave de la motilidad intestinal. El sobrecrecimiento bacteriano intestinal (SBI) se asocia frecuentemente a estados de dismotilidad. A pesar de esta asociación existen escasos datos sobre la relación entre POIC y SBI. Objetivo: Determinar SBI en pacientes con POIC en período inter-crisis. Comparar características clínicas y manométricas de pacientes con y sin SBI. Material y Método: Análisis retrospectivo de 40 pacientes con POIC (edad promedio: 41 años, rango: 18-76 años; 75 por ciento mujeres). Se registraron síntomas (dolor, distensión, vómitos, constipación, diarrea, baja de peso), hallazgos en manometría intestinal (patrón neuropático, miopático o mixto, índice de motilidad intestinal (IMI)) y SBI con test de H2 con lactulosa, definido como la elevación > 20 ppm en 2 o más cifras en los primeros 60 min. Análisis estadístico: t-test y comparación de 2 proporciones. Resultados: Se observó SBI en 60 por ciento de los pacientes con POIC. Tres o más síntomas se presentaron en 70,8 por ciento de los pacientes con SBI vs 50 por ciento en POIC sin SBI (p = NS). El síntoma dolor abdominal fue más frecuente en pacientes con SBI (70,8 por ciento vs 31,2 por ciento, p = 0,032). No hubo diferencias entre pacientes con SBI y los distintos patrones de motilidad, sin embargo, el IMI fue menor para el grupo con SBI (9,7 +/- 1,44 vs 12,3 +/- 1,7, p < 0,001). Conclusiones: Existe una alta prevalencia de SBI en pacientes con POIC. Esto se relaciona con mayor compromiso de la motilidad intestinal evaluado por el IMI.

Profiling carbohydrate composition, biohydrogen capacity, and disease resistance in potato

Background: Potato (Solanum tuberosum) is one of the most important sources of carbohydrates in human diet. Because of its high carbohydrate levels it recently has also received attention in biohydrogen production. To exploit the natural variation of potato with respect to resistance to major diseases, carbohydrate levels and composition, and capacity for biohydrogen production we analyzed tubers of native, improved, and genetically modified potatoes, and two other tuberous species for their glucose, fructose, sucrose, and starch content. Results: High-starch potato varieties were evaluated for their potential for Caldicellulosiruptor saccharolyticus-mediated biohydrogen production with Desirée and Rosita varieties delivering the highest biohydrogen amounts. Native line Vega1 and improved line Yagana were both immune to two isolates (A291, A287) of Phytophthora infestans. Conclusions: Our data demonstrate that native potato varieties might have great potential for further improving the multifaceted use of potato in worldwide food and biohydrogen production.

Association between Symptoms of Irritable Bowel Syndrome and Methane and Hydrogen on Lactulose Breath Test

Whether hydrogen and methane gas produced during lactulose breath test (LBT) are associated with symptoms of irritable bowel syndrome (IBS) is not determined. We aimed to investigate whether hydrogen and methane on LBT are associated with IBS symptoms. Sixty-eight IBS patients meeting the Rome III criteria for IBS, and 55 healthy controls, underwent LBT. The IBS subjects recorded their customary gastrointestinal symptoms on a questionnaire using visual analogue scales. LBT positivity was defined to be above 20 ppm rise of hydrogen or 10 ppm rise of methane within 90 min. Gas amounts produced during LBT were determined by calculating area under the curve of hydrogen and methane excretion. Symptom severity scores were not different between the LBT (+) IBS and LBT (-) IBS subjects and also between methane producers and non-methane producers. Gas amounts produced during LBT were not associated with IBS symptoms, except a weak correlation between total gas amounts and a few IBS symptoms such as bloating (r = 0.324, P = 0.039), flatulence (r = 0.314, P = 0.046) and abdominal pain (r = 0.364, P = 0.018) only in LBT (+) IBS. In conclusion, hydrogen and methane gas on LBT are not useful for predicting the customary symptoms and subtypes of IBS.

Evaluation of small intestine bacterial overgrowth in patients with functional dyspepsia through H2 breath test / Avaliação de supercrescimento bacteriano no intestino delgado em pacientes com dispepsia funcional, utilizando o teste de H2 no ar expirado

CONTEXT: Functional dyspepsia is a condition in which symptoms are not related to organic underlying disease; its pathogenesis is not well known. The small intestinal bacterial overgrowth (SIBO) is characterized by the increase in the number and/or type of colonic bacteria in the upper gastrointestinal tract. The hypothesis of SIBO being associated to functional dyspepsia must be considered, since the impaired motility of the gastrointestinal tract is one of the main etiologic factors involved on both pathologies. OBJECTIVE: To determine if there is SIBO in patients with functional dyspepsia. METHODS: Case-control study, evaluating 34 patients: 23 functional dyspeptic and 11 non-dyspeptic (control group). Questionnaire applied based on Rome III criteria. The patients underwent H2-lactulose breath test, considered positive when: H2 peak exceeding 20 ppm, in relation to fasting, or two peaks exceeding 10 ppm sustained until 60 minutes. RESULTS: Of the 23 dyspeptic patients, 13 (56.5%) obtained positive results for SIBO trough the H2-lactulose breath test. On control group, SIBO was not observed. The association between the dyspeptic group and the control group regarding SIBO was statistically significant, with P = 0.0052. In the group of dyspeptic patients, 12 (52.2%) were using proton pump inhibitor; of these 9 (75%) were positive for SIBO. In the control group, none of the 11 patients used proton pump inhibitors and SIBO was not observed. The association of the dyspeptic group using proton pump inhibitor that were positive for SIBO and the control group was statistically significant, with P = 0.0011. CONCLUSION: It was found that, patients with functional dyspepsia presented SIBO, when they underwent to H2-lactulose breath test, compared to the non-dyspeptic. In addition, it was observed a higher prevalence of SIBO in dyspeptic patients that were using proton pump inhibitors, compared to control group.

CONTEXTO: A dispepsia funcional é uma afecção cujos sintomas não estão relacionados à doença de base orgânica; sua etiopatogenia não é bem definida. O supercrescimento bacteriano no intestino delgado (SBID) é caracterizado pelo aumento do número e/ou tipo de bactérias colônicas no trato gastrointestinal superior. A hipótese de SBID associado à dispepsia funcional deve ser considerada, uma vez que o distúrbio de motilidade do trato gastrointestinal é um dos principais fatores etiológicos envolvidos nas duas patologias. OBJETIVO: Determinar se há presença de SBID em pacientes com dispepsia funcional. MÉTODO: Estudo caso-controle, avaliando 34 pacientes: 23 dispépticos funcionais e 11 não dispépticos (grupo controle). Questionário baseado nos critérios de Roma III foi aplicado. Os pacientes se submeteram ao teste de H2 no ar expirado com lactulose, considerado positivo: pico de H2 superior a 20 ppm, em relação ao jejum ou dois picos superiores a 10 ppm sustentados até 60 minutos. RESULTADOS: Dos 23 pacientes dispépticos, 13 (56.5%) obtiveram resultado positivo para SBID através do teste de H2 no ar expirado. No grupo controle, não foi evidenciado SBID. A associação entre o grupo dispéptico e o grupo controle em relação ao SBID, mostrou-se estatisticamente significante, com P = 0.0052. Do grupo dispéptico, 12 (52.2%) pacientes faziam uso de inibidor de bomba de prótons; destes, 9 (75%) apresentaram resultado positivo para SBID. No grupo controle, os 11 pacientes não usavam inibidor de bomba de prótons e não foi evidenciado SBID. Mostrou-se estatisticamente significante a associação do grupo de dispépticos em uso de inibidor de bomba de prótons que tiveram SBID e grupo controle, com P = 0.0011. CONCLUSÃO: Concluiu-se que, pacientes com dispepsia funcional apresentaram SBID, quando submetidos ao teste de H2 no ar expirado, em relação aos não-dispépticos. Além disso, observou-se maior prevalência de SBID em pacientes dispépticos que faziam uso de inibidor de bomba de prótons, em relação ao grupo controle.

Estudio comparativo de dos equipos para el test de H2 en aire espirado / Evaluation of breath H2 measured by means of two different analyzers

El test de hidrógeno (H2) en aire espirado es ampliamente utilizado en el estudio de malabsorción de hidratos de carbono, sobrecrecimiento bacteriano intestinal (SBI) y tiempo de tránsito orocecal (TTOC). Objetivo: Comparar los resultados obtenidos por dos equiposde detección de H2, uno de ellos de introducción reciente en nuestro medio. Material y Métodos: 50 pacientes, edad promedio 38,5 +/- 5,2 años (rango 7-77 años), 40 mujeres, se les realizó el test de H2 en aire espirado en paralelo con ambos equipos bajo métodos estandarizados. En 25 de ellos se investigó la presencia de malabsorción de lactosa, y en los otros 25, la presencia de SBI con lactulosa. Se evaluaron los valores de H2 obtenidos con ambos equipos. Resultados: Las lecturas de H2 con ambos equipos no mostraron diferencias significativas tanto para lactosa (p > 0,1), como para lactulosa (p > 0,5). Tampoco hubo diferencias en el TTOC de los pacientes (90 +/- 33,75 min v/s 90.8 +/- 32,42 min) (p > 1). Se obtuvo un índice de concordancia Kappa de 0,92 entre ambos equipos con el test con lactosa y con lactulosa. Conclusión: El equipo portátil es altamente confiable, entregando resultados con una excelente concordancia con respectoal equipo de referencia.

The hydrogen (H2) breath test (BT) is widely used to investigate carbohydrates malabsorption, small intestinal bacterial overgrowth (SIBO) and orocaecal transit time (OTT). Aim: To compare the results of two hydrogen breath devices, one of them, of recent introduction in our country. Methods: Fifty patients were included, mean age 38.5 +/- 5.2years (range 7-77 yrs), 40 women, H2 BT was performed in parallel with both analyzers under standardized methods. Lactose malabsorption was investigated in 25 patients with lactose, and the presence of SIBO in the resting 25 patients, with lactulose, hydrogen values obtained with both devices were evaluated. Results: No differences were observed between the H2 concentrations for lactose BT (p > 0.1) as well as lactulose BT (p > 0.5)and also between the OTT measured by the two devices (90 +/- 33.75 min. v/s 90.8 +/- 32.42 min) (p > 1). We detected a Kappa concordance index of 0.92 for both equipments. Conclusion: The portable device is highly reliable to detect the presence of breath hydrogen, giving results with an excellent concordance to the reference device.

El uso de inhibidores de bomba de protones y el hábito de fumar no modifican la tasa de sobrecrecimiento bacteriano intestinal en pacientes con patología digestiva funcional / Small intestinal bacterial overgrowth is not influenced by proton pump inhibitors and smoking habit in patient with funtional gastrointestinal disorders

Background: Drug induced inhibition of acid secretion has been associated to small intestinal bacterial overgrowth (SIBO). Smoking is followed by an increase of exhaled and orocecal transit time (OCTT). Aim: To investigate if the use of proton pump inhibitiors (PPI) and smoking can modifie the incidence of SIBO in patients with functional gastrointestinal disease. Patients and Methods: Questionnaires performed before a study for SIBO in patients with functional gastrointestinal disorders were analyzed. The use PPI and the smoking habit were recorded. The presence of SIBO and the OCTT was determined by means of the lactulose hydrogen breath test. Results: 437 patients, mean age 45 years (range: 14-93), 337 (77 percent) female, entered in the study SIBO was present in 356 patients, and 81 patients had normal H2 breath test. Both groups had a similar distribution of gender and age. The percentage of SIBO was no different in patients using PPI or presenting smoking habit Conclusions: Use of PPI and smoking habit are not risk factors for the development of SIBO in patients with functional disorders.

Los fármacos que inhiben la secreción gástrica favorecen el sobrecrecimiento bacteriano intestinal (SBI), mientras que el habito de fumar puede aumentar los niveles de H2 espirado y el tiempo de transito orocecal (TTOC). Objetivo: Investigar si el uso de inhibidores de la bomba de protones (IBP) y el habito de fumar modifican la incidencia de SBI en pacientes con trastornos digestivos funcionales. Pacientes y Métodos: Se analizaron encuestas de pacientes con patología digestiva funcional previas a un estudio de SBI Se consignaron el uso de IBP Y el hábito tabáquico en los 6 meses que precedieron al examen. La presencia de SBI y el tiempo de transito orocecal (TTOC) se determinaron con el test de hidrógeno en aire espirado con lactulosa. Resultados: 437 pacientes, con edad x 45 años (rango: 14-93),337 (77 por ciento) mujeres. Con SBI 356 pacientes, sin SBI 81 pacientes. Ambos grupos fueron comparables en cuanto a distribución por sexo y edad. El porcentaje de pacientes con SBI no fue diferente en pacientes con antecedente de uso de IBP o con hábito tabaquito. Conclusiones: El antecedente del uso de IBP y el tabaquismo no constituyen un factor de riesgo para SBI en pacientes con patología digestiva funcional.

Sobrecrecimiento bacteriano intestinal en pacientes con pancreatitis crónica / Small intestine bacterial overgrowth in patients with chronic pancreatitis

Background: Previous reports describe 30-40 percent of small intestine bacterial overgrowth (SIBO) in patients with chronic pancreatitis (CP), SIBO is a cause of persistent symptoms in this group of patients even when they are treated with pancreatic enzymes. Aim: To asses the frequency of SIBO in patients with CP. Patients and methods: We studied 14 patients with CP using an hydrogen breath test with lactulose to detect SIBO, a nonabsorbable carbohydrate, whose results are not influenced by the presence of exocrine insufficiency. Main symptoms and signs were bloating in 9 (64 percent), recurrent abdominal pain in 8 (57 percent), intermittent diarrhea in 5 (36 percent) and steatorrhea in 5 (36 percent). At the same time we studied a healthy control group paired by age and sex. Results: SIBO was present in 13 of 14 patients with CP (92 percent) and in 1 of 14 controls (p<0.001). The only patient with CP and without SIBO was recently diagnosed and had minimal morphologic alterations in computed tomography and endoscopic pancreatography Conclusions: SIBO is common in CP and may be responsible for persistent symptoms. Proper diagnosis and treatment could alleviate symptoms and improve quality of life.

Sobrecrecimiento bacteriano intestinal un factor de riesgo de peritonitis bacteriana espontánea y mortalidad en pacientes con cirrosis hepática / Intestinal bacterial overgrowth is a risk factor for spontaneous bacterial peritonitis and mortality in patients with liver cirrhosis

Spontaneous bacterial peritonitis (SBP) is a major and serious complication of liver cirrhosis. Small intestinal bacterial overgrowth (SIBO) has been shown to occur with increased frequency in patients with cirrhosis. Studies have suggested that SIBO may contribute to the development of SBP. Aims: to assess the prevalence of SIBO and its relationship with the mortality in patients with cirrhosis. Patients and Methods: One hundred three cirrhotic patients, 62 male, mean age 56.6 (range 35-89) entered in the study in a four year period with a mean follow-up of 22.2 months (range 3-76). SIBO was evaluated by breath hydrogen test (BHT) with lactulose. A positive BHT was defined as an increase of 20 ppm during the first 60 min after lactulose ingestion. SBP was diagnosed by a polymorphonuclear leukocyte count greater than or equal to of 250 cells/mm3 in ascitic fluid. Results: A 50 percent of cirrhotic patients had SIBO at the beginning of follow-up period. The prevalence of SIBO was similar in patients with Child-Pugh class A, B, or C (48 percent 51 percent and 48 percent patients respectively). The presence of SBP was significantly higher in patients with SIBO (17/54 patients) than patients without SIBO (1/53 patients), p < 0.05. The mortality of cirrhotic patients was higher in the SIBO group than in the non-SIBO group (25/50 versus 16/35 patients. p < 0.05). Conclusions: The results of this study confirm that the presence of SIBO is a risk factor for SBP and mortality in patients with liver cirrhosis. SIBO should be investigated and treated during the follow-up in these patients.

La peritonitis bacteriana espontánea (PBE) es una complicación frecuente y grave en pacientes con cirrosis hepática. El sobrecrecimiento bacteriano intestinal (SBI) ha sido descrito con frecuencia en pacientes con cirrosis. Estudios han sugerido que el SBI puede ser un factor importante en el desarrollo de la PBE. Objetivos: Evaluar la prevalencia de SBI y su relación con la mortalidad en pacientes con cirrosis hepática. Pacientes y métodos: Ciento tres pacientes cirróticos, 67 hombres, edad promedio 58,6 (rango 35-89) entraron al estudio en un período de cuatro años con un seguimiento promedio de 22,2 meses (rango 3-76). El SBI fue evaluado por test de hidrógeno en aire espirado (THE) con lactulosa. Un examen era considerado positivo con un nivel mayor de 20 ppm después de la ingesta de lactulosa en los primeros 60 min. El diagnóstico de PBE se fundamentó en un recuento de polimorfonucleares mayor o igual que 250 células/mm3 en muestra de líquido ascítico. Resultados: El 50 por ciento de los pacientes cirróticos presentó SBI al comienzo de su seguimiento. La prevalencia de SBI fue similar en pacientes cirróticos Child-Pugh A, B, o C (48 por ciento, 50 por ciento y 50 por ciento respectivamente). La presencia de PBE fue significativamente mayor en pacientes con SBI (17/50 pacientes) que en pacientes sin SBI (1/53 pacientes). p < 0,05. La mortalidad de los pacientes cirróticos fue mayor en el grupo con SBI que en el grupo sin SBI (25/50 versus 16/53 pacientes, p < 0,05). Conclusiones: Los resultados de este estudio confirman que la presencia de SBI es un factor de riesgo de PBE y mortalidad en pacientes con cirrosis hepática. El SBI debería ser investigado y tratado durante el seguimiento de estos pacientes.

Correlation between lactose absorption and the C/T-13910 and G/A-22018 mutations of the lactase-phlorizin hydrolase (LCT) gene in adult-type hypolactasia

The C/T-13910 mutation is the major factor responsible for the persistence of the lactase-phlorizin hydrolase (LCT) gene expression. Mutation G/A-22018 appears to be only in co-segregation with C/T-13910. The objective of the present study was to assess the presence of these two mutations in Brazilian individuals with and without lactose malabsorption diagnosed by the hydrogen breath test (HBT). Ten milk-tolerant and 10 milk-intolerant individuals underwent the HBT after oral ingestion of 50 g lactose (equivalent to 1 L of milk). Analyses for C/T-13910 and G/A-22018 mutations were performed using a PCR-based method. Primers were designed for this study based on the GenBank sequence. The CT/GA, CT/AA, and TT/AA genotypes (lactase persistence) were found in 10 individuals with negative HBT. The CC/GG genotype (lactase non-persistence) was found in 10 individuals, 9 of them with positive HBT results. There was a significant agreement between the presence of mutations in the LCT gene promoter and HBT results (kappa = -0.9, P < 0.001). The CT/AA genotype has not been described previously and seems to be related to lactase persistence. The present study showed a significant agreement between the occurrence of mutations G/A-22018 and C/T-13910 and lactose absorption in Brazilian subjects, suggesting that the molecular test used here could be proposed for the laboratory diagnosis of adult-type primary hypolactasia.

Experimental and bioinformatic approaches for analyzing and visualizing cyanobacterial nitrogen and hydrogen metabolism

Many cyanobacteria are capable of utilizing light energy for nitrogen fixation. As a by-product of this nitrogenase mediated catalysis, hydrogen gas is produced. Several approaches to increase hydrogen production from cyanobacteria exist. Usually, these approaches are non-targeted. Here we exemplify how DNA-microarray based gene-expression analysis and bioinformatic visualization techniques can be used to analyze nitrogen and hydrogen metabolism from the filamentous, heterocyst forming cyanobacterium Nostoc PCC 7120. We analyzed the expression of 1249 genes from major metabolic categories under nitrogen fixing and non-nitrogen fixing growth. Of the selected genes, 494 show a more than 2-fold expression difference in the two conditions analyzed. Under nitrogen-fixing conditions 465 genes, mainly involved in energy metabolism, photosynthesis, respiration and nitrogen-fixation, were found to be stronger expressed, whereas only 29 genes showed a stronger expression under non-nitrogen fixing conditions. To help understanding probe hybridization, all expression data were correlated with potential target secondary structures and probe GC-content. For the first time the expression of high light-induced stress proteins (HLIP-family) is shown to be linked to the nitrogen availability.

El incremento del hidrógeno en el aire espirado no predice la intolerancia a la fibra en la dieta en el síndrome del intestino irritable con constipación: estudio piloto / Breath hydrogen levels do not predict fiber intolerance in irritable bowel syndrome with constipation

BACKGROUND: Irritable Bowel Syndrome (IBS) is characterized by the worsening of symptoms with a high fiber diet. This intolerance could be related to an increase in colonic bacterial fermentation. The hydrogen breath test (HBT) is a marker of the intestinal micro flora fermentative capacity. AIM: To assess if there is an association between hydrogen (H2) levels and clinical changes between diets with and without bran. PATIENTS AND METHODS: 10 women with predominantly constipated irritable bowel syndrome (Rome II criteria) received a lowfiber diet during one week. This phase was followed by a second 7 day period with the same diet but supplemented with 12 g of crude dietary fiber. At the end of both periods, patients completed a symptom scale (Lickert type) and performed a HBT. RESULTS: Comparing both periods with a different diet the median difference in the clinical scale score (-2.5) shows a tendency favorable to the diet without bran, p = 0.048. In the fiber period the median increase of 2 ppm in H2 values was not significant deferent. Neither was possible to establish an association between breath H2 and the clinical response to a fiber diet. CONCLUSIONS: In this pilot study we could not detect ary association between breath H2 levels and the clinical response to dietary fiber.

Introducción: Los pacientes con síndrome del intestino irritable (SII) frecuentemente agravan sus síntomas cuando incorporan fibra insoluble en su dieta. Esta intolerancia podría estar relacionada con una incrementada fermentación colónica. El nivel de hidrógeno en el aire espirado es una variable dependiente de la capacidad fermentativa del contenido bacteriano del intestino por lo que podría representar un recurso capaz de predecir el grado de intolerancia a la fibra dietética. Objetivo: El objetivo de este estudio piloto fue investigar si existe una asociación entre los niveles de hidrógeno (H2) en el aire espirado y la respuesta clínica a las dietas con y sin fibra. Pacientes y métodos: En este estudio piloto se incluyeron diez mujeres afectadas de síndrome de intestino irritable con constipación (Criterios Roma II). Siguieron una dieta poco fermentable durante 14 días. En la primera semana las pacientes se sujetaron a la dieta sin ningún agregado, en la segunda semana incorporaron 12 gr diarios de fibra dietaria cruda. Al finalizar ambos períodos las pacientes completaron una escala de Lickert de 7 ítems donde se valoró la respuesta clínica a la dieta administrada y se midió la excreción de H2 en el aire espirado. Resultados: Comparando ambas dietas, se observó que la mediana de las diferencias de los puntajes clínicos (-2,5) indicaba una tendencia favorable a la dieta poco fermentable sin fibra, p=0,048. El incremento de la mediana de la concentración de H2 en el aire espirado fue de 2 ppm para la dieta con fibra, pero el mismo no fue significativo. Tampoco se pudo demostrar una tendencia que permitiera relacionar los valores de H2 con la respuesta clínica a la fibra dietética. Conclusión: Los resultados de este estudio no lograron demostrar una asociación entre los niveles de hidrógeno en el aire espirado y la respuesta clínica a la dieta con fibra.

Sobrecrecimiento bacteriano del intestino delagado: presentación clínica en la edad pediátrica / Bacterial overgrowth of the intestine small: clinical presentation in pediatric age

El sobrecrecimiento bacteriano es la colonización del intestino delgado por microrganismos gram-negativos y anaerobios. Las bacterias del sobrecrecimiento bacteriano del intestino delgado pueden provenir tanto de la flora bacteriana colónica como del ambiente (ingestión de agua y alimentos contaminados). En la enteropatía ambiental, por ejemplo, el SCBID es debido al aumento de la carga bacteriana ingerida. La prueba de hidrógeno en aire espirado con lactulosa se utiliza cada vez más para el diagnóstico de SCBID, sobre todo en pacientes pediátricos. Determinar la incidencia de SCBID y precisar sus formas de presentación clínica. Estudio longitudinal prospectivo realizado desde marzo de 2002 hasta noviembre de 2003. Se incluyeron los pacientes que consultaron por presentar: distensión abdominal, gases, dispepsia, diarrea crónica y dolor abdominal. El plan de estudio incluyó: historia clínica, categorización socio-económica, evaluación antropométrica, examen de heces, endoscopia digestiva superior y prueba de hidrógeno en aire espirado con lactulosa. Los pacientes con diagnóstico SCBID recibieron metronidazol por 14 días. Se incluyeron 88 pacientes (6,88±4,03 años y 63,63 por ciento femenino). La prueba de hidrógeno en aire espirado con lactulosa fue positiva en 73 pacientes (82,95 por ciento). La forma clínica de presentación de los pacientes con SCBID fue: dispepsia en 57,14 por ciento, dolor abdominal en 28,57 por ciento, dispepsia con distensión abdominal en 3,57 por ciento, dolor abdominal con distensión en 3,57 por ciento y diarrea en 7,14 por ciento. La incidencia de SCBID fue de 5.2 por cada 100 pacientes referidos. Dispepsia y dolor abdominal fueron las formas clínicas de presentación más frecuentes en la edad pediátrica.