Lígia Cristina Fonseca Lahoz Melli

Intestinal microbiota and allergic diseases: A systematic review

Evidence suggests that possible imbalances in intestinal microbiota composition may be implicated in the occurrence of allergic diseases. Although several studies published until 2006 indicated a correlation between microbiota composition and allergic symptoms, it has not been possible to distinguish protective microorganisms from those associated with increased risk of allergic diseases. Therefore, the objective of this study was to review the studies published since 2007 that address the intestinal microbiota in allergic diseases. Twenty-one studies were identified after excluding those that performed a clinical intervention before stool collection. In the early microbiota of children who later developed allergies, lower bacterial diversity was observed, with a predominance of Firmicutes; a higher count of Bacteroidaceae; a higher prevalence of the anaerobic bacteria Bacteroides fragilis, Escherichia coli, Clostridium difficile, Bifidobacterium catenulatum, Bifidobacterium bifidum, and Bifidobacterium longum; and a lower prevalence of Bifidobacterium adolescentis, B. bifidum, and Lactobacillus. In the microbiota of allergic children whose intestinal microbiota was assessed at the onset of allergic symptoms, there was a higher count of Bacteroides; a lower count of Akkermansia muciniphila, Faecalibacterium prausnitzii, and Clostridium; a higher prevalence of B. adolescentis; a lower prevalence of B. catenulatum and Staphylococcus aureus; and a lower bacterial diversity.

Methane production and small intestinal bacterial overgrowth in children living in a slum.

AIM To analyze small intestinal bacterial overgrowth in school-aged children and the relationship between hydrogen and methane production in breath tests. METHODS This transversal study included 85 children residing in a slum and 43 children from a private school, all aged between 6 and 10 years, in Osasco, Brazil. For characterization of the groups, data regarding the socioeconomic status and basic housing sanitary conditions were collected. Anthropometric data was obtained in children from both groups. All children completed the hydrogen (H(2)) and methane (CH(4)) breath test in order to assess small intestinal bacterial overgrowth (SIBO). SIBO was diagnosed when there was an increase in H(2) ≥ 20 ppm or CH(4) ≥ 10 ppm with regard to the fasting value until 60 min after lactulose ingestion. RESULTS Children from the slum group had worse living conditions and lower nutritional indices than children from the private school. SIBO was found in 30.9% (26/84) of the children from the slum group and in 2.4% (1/41) from the private school group (P = 0.0007). Greater hydrogen production in the small intestine was observed in children from the slum group when compared to children from the private school (P = 0.007). A higher concentration of hydrogen in the small intestine (P < 0.001) and in the colon (P < 0.001) was observed among the children from the slum group with SIBO when compared to children from the slum group without SIBO. Methane production was observed in 63.1% (53/84) of the children from the slum group and in 19.5% (8/41) of the children from the private school group (P < 0.0001). Methane production was observed in 38/58 (65.5%) of the children without SIBO and in 15/26 (57.7%) of the children with SIBO from the slum. Colonic production of hydrogen was lower in methane-producing children (P = 0.017). CONCLUSION Children who live in inadequate environmental conditions are at risk of bacterial overgrowth and methane production. Hydrogen is a substrate for methane production in the colon.

High prevalence of antimicrobial drug-resistant diarrheagenic Escherichia coli in asymptomatic children living in an urban slum

PURPOSE The aim of this study was to investigate the presence of diarrheagenic Escherichia coli and antibiotic resistance in asymptomatic school-age children living in an area with defective environmental sanitation, comparing with children registered at a private school, both in the city of Osasco, Brazil. METHODS Seventy-nine school-age children between 5 and 10 years living in a slum and 35 children who attended a private school of the same city were included in the study. RESULTS DEC was found in 58% of the children living in the slum and in 17% of the control group (P=0.001). Resistance to at least one antimicrobial drug was found in 65% of DEC strains; resistant to two or more antimicrobial drugs was found in 46% of strains. CONCLUSION The high carriage status among the slum children point towards the widespread environment contamination in low socio-economic housing conditions, in conformance with the pediatric population at higher risk for developing DEC diarrhea.

Temporal trends and inequality in under-5 mortality from diarrhea

OBJECTIVE To analyze the trend in mortality due to diarrhea among children under 5 in the town of Osasco (SP), Brazil, between 1980 and 2000. METHODS This is a descriptive observational study with two different designs, the first using individuals as the unit of study, and the other ecological, using groups of individuals as units of observation and including time series analysis. Data were obtained from the state of São Paulo information system of deaths and the results of the 1980, 1991 and 2000 censuses. Seasonal variations were described and log linear polynomial regression models were employed to analyze trends, using the sociodemographic characteristics of mothers and their children. Analyses were carried out of the changes in the towns sociodemographic indicators from 1980 to 2000, the average mortality rates among under-5s due to diarrhea and the differences between districts during the 1990s. RESULTS There were a total of 1,360 deaths, 94.3% of which were before 1 year of age and 75.3% of which were before 6 months. There was a 98.3% reduction in mortality and the period of peak mortality shifted from summer to autumn/fall. The median age at death increased from 2 months at the first three quinquenium of study to 3 months at the last. The residual deaths were among the children of mothers aged 20 to 29 years and of mothers who had spent less than 8 years in education. The relative risk between the worst-affected district and the average rate for the town reduced from 3.4 to 1.3 from the first 5 years of the 1990s to the second half of the decade. CONCLUSIONS Our results demonstrate an increase in the age of greatest vulnerability and indicate that it is probable that the agent most often linked with mortality due to diarrhea has changed.

Lactobacilli and bifidobacteria in the feces of schoolchildren of two different socioeconomic groups: children from a favela and children from a private school

OBJECTIVE: To determine the number of lactobacillus and bifidobacterium colonies in the feces of schoolchildren from two different socioeconomic levels. METHODS: We analyzed fecal samples of children aged 6 to 10 years without gastrointestinal symptoms or recent use of antimicrobials. The first group included 86 children living in a favela in the city of Osasco, state of Sao Paulo, southeastern Brazil. The second group included 36 children attending a private school in the same city. Body mass index (BMI) was used to assess nutritional status according to the reference values of the National Center for Health Statistics (NCHS). Specific anaerobic culture media were used for isolation of colonies for 48 and 72 hours at 37 °C. The number of colonies was determined using the plate-counting method. RESULTS: The mean lactobacillus (1.125 x 109 colony-forming units, CFU/g) and bifidobacterium (1.675 x 109 CFU/g) counts in the private school group were higher (p -1.0 SD (n = 57): 0.350 x 109 and 0.420 x 109 CFU/g, respectively. CONCLUSION: The microbiota of schoolchildren living in unfavorable environmental conditions shows lower numbers of fecal lactobacillus and bifidobacterium colonies, especially in children with lower BMI values.

Effectiveness of trimethoprim-sulfamethoxazole and metronidazole in the treatment of small intestinal bacterial overgrowth in children living in a slum.

ABSTRACT Trimethoprim-sulfamethoxazole and metronidazole were used for 14 days to treat 20 children with small intestine bacterial overgrowth (SIBO). SIBO was diagnosed using the lactulose hydrogen breath test. The breath test was repeated 1 month after treatment, and 19 (95.0%) of 20 children showed no evidence of SIBO (P < 0.001). The area under the individual curves showed that children with SIBO exhibited greater hydrogen production before treatment in both the first hour and between 60 and 180 minutes after the breath test. The treatment did not decrease methane production. In conclusion, trimethoprim-sulfamethoxazole and metronidazole was effective in treating children with SIBO.

Children Living near a Sanitary Landfill Have Increased Breath Methane and Methanobrevibacter smithii in Their Intestinal Microbiota

This study evaluated the breath CH4 excretion and concentration of M. smithii in intestinal microbiota of schoolchildren from 2 slums. One hundred and eleven children from a slum near a sanitary landfill, 35 children of a slum located away from the sanitary landfill, and 32 children from a high socioeconomic level school were included in the study. Real-time PCR was performed to quantify the M. smithii nifH gene and it was present in the microbiota of all the participating children, with higher (P < 0.05) concentrations in those who lived in the slum near the landfill (3.16 × 107 CFU/g of feces), comparing with the children from the slum away from the landfill (2.05 × 106 CFU/g of feces) and those from the high socioeconomic level group (3.93 × 105 CFU/g of feces). The prevalence of children who present breath methane was 53% in the slum near the landfill, 31% in the slum further away from the landfill and, 22% in the high socioeconomic level group. To live near a landfill is associated with higher concentrations of M. smithii in intestinal microbiota, comparing with those who live away from the landfill, regardless of their socioeconomics conditions.

Gut Microbiota Differences in Children from Distinct Socioeconomic Levels Living in the Same Urban Area in Brazil.

Objective: To compare gut microbiota in impoverished children versus children of high socioeconomic status living in the same urban area in Brazil. Methods: A cross-sectional study was conducted to evaluate 100 children living in a slum and 30 children from a private school, ages between 5 and 11 years old, in Sao Paulo State, Brazil. To characterize the groups, data based on socioeconomic status, sanitation, and housing conditions were collected. Anthropometric measurements and neonatal data were obtained from both groups. Gut microbiota were quantified in fecal samples by real-time polymerase chain reaction. Results: The children in the private school group had higher rates of cesarean delivery and premature birth than the children in the slum group. Staphylococcus aureus (90% vs 48.0%) and Clostridium difficile (100% vs 43.0%) were more commonly found in the children from the private school than in the impoverished children (P < 0.0001). C perfringens was most frequently identified in the group of children from the slum (92.0% vs 80%; P = 0.064). Higher counts of total eubacteria, Firmicutes and Bacteroidetes phyla organisms, Escherichia coli, Lactobacillus spp., and Methanobrevibacter smithii were found in the children living in poverty, whereas higher counts of Salmonella spp., C difficile, and C perfringens were observed in the children living in satisfactory housing conditions (P < 0.05). Conclusions: Important differences were observed between the gut microbiota of children living under distinct socioeconomic and environmental conditions within the same city. Our findings suggest that children of high socioeconomic status have less favorable gut microbiota than do children who live in poverty.

Parasitoses intestinais se associam a menores índices de peso e estatura em escolares de baixo estrato socioeconômico

OBJETIVO: Evaluar la prevalencia de parasitosis intestinales correlacionandolas con los factores socioeconomicos y ambientales, peso, estatura y hemoglobina, en ninos de dos niveles socioeconomicos en el municipio de Osasco, Sao Paulo (Brasil). METODOS: Se realizo un estudio transversal, comparando 84 ninos entre 6 y 10 anos, residentes en area sin saneamiento ambiental y vivienda precaria, con 35 ninos de escuela privada en el mismo municipio, que poseian buenas condiciones socioeconomicas y de vivienda. Se excluyeron aquellas con diarrea hace menos de 30 dias o enfermedad grave. Se utilizo cuestionario estandarizado para evaluar las condiciones socioambientales. La evaluacion nutricional fue realizada mediante escores Z de peso para la edad, estatura para la edad e indice de masa corporal. La determinacion de la hemoglobina en muestra de sangre capilar fue realizada por el metodo Hemocueâ y la investigacion de parasitas intestinales por los metodos de Hoffman, Ritchie, Kinyoun y Swab anal. RESULTADOS: Parasitosis intestinal ocurrio en 60,7% de los ninos del suburbio y en 5,9% de los ninos de la escuela privada (p<0,001; OR 24,7). El promedio de los escores Z de peso para la edad, estatura para la edad e indice de masa corporal fue menor en los ninos parasitados (-0,78±0,84; +0,50±0,90; -0,76±0,96) respecto a aquellos no parasitados (-0,18±1,18; +0,03±1,10; -0,28±1,16), siendo las diferencias estadisticamente significantes (p<0,05). No hubo diferencia en los valores promedios de hemoglobina entre los ninos parasitados y los no parasitados del grupo del suburbio (12,6±1,1g/dL y 12,8±1,2g/dL), (p=0,58). CONCLUSIONES: La parasitosis intestinal fue mas prevalente en ninos del suburbio y se asocio a menores indices de peso y estatura.

Intestinal parasitoses are associated with lower values of weight and height in school-aged children from low socioeconomic level

OBJETIVO: Evaluar la prevalencia de parasitosis intestinales correlacionandolas con los factores socioeconomicos y ambientales, peso, estatura y hemoglobina, en ninos de dos niveles socioeconomicos en el municipio de Osasco, Sao Paulo (Brasil). METODOS: Se realizo un estudio transversal, comparando 84 ninos entre 6 y 10 anos, residentes en area sin saneamiento ambiental y vivienda precaria, con 35 ninos de escuela privada en el mismo municipio, que poseian buenas condiciones socioeconomicas y de vivienda. Se excluyeron aquellas con diarrea hace menos de 30 dias o enfermedad grave. Se utilizo cuestionario estandarizado para evaluar las condiciones socioambientales. La evaluacion nutricional fue realizada mediante escores Z de peso para la edad, estatura para la edad e indice de masa corporal. La determinacion de la hemoglobina en muestra de sangre capilar fue realizada por el metodo Hemocueâ y la investigacion de parasitas intestinales por los metodos de Hoffman, Ritchie, Kinyoun y Swab anal. RESULTADOS: Parasitosis intestinal ocurrio en 60,7% de los ninos del suburbio y en 5,9% de los ninos de la escuela privada (p<0,001; OR 24,7). El promedio de los escores Z de peso para la edad, estatura para la edad e indice de masa corporal fue menor en los ninos parasitados (-0,78±0,84; +0,50±0,90; -0,76±0,96) respecto a aquellos no parasitados (-0,18±1,18; +0,03±1,10; -0,28±1,16), siendo las diferencias estadisticamente significantes (p<0,05). No hubo diferencia en los valores promedios de hemoglobina entre los ninos parasitados y los no parasitados del grupo del suburbio (12,6±1,1g/dL y 12,8±1,2g/dL), (p=0,58). CONCLUSIONES: La parasitosis intestinal fue mas prevalente en ninos del suburbio y se asocio a menores indices de peso y estatura.