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.

Dietary fiber mixture in pediatric patients with controlled chronic constipation.

OBJECTIVES: The aim of the study was to test the clinical efficacy and effect on colonic transit time (CTT) of a dietary fiber mixture given to children with controlled chronic constipation (CC) after the withdrawal of stool softeners and enemas. METHODS: This randomized, placebo-controlled, double-blind clinical trial involved 54 patients aged 4 to 12 years and had CC that was controlled by the use of low-dose stool softeners. The use of these softeners was discontinued when the patients were admitted to the clinical trial. The patients were randomized into 2 groups for the 4-week study period. One group received a dietary fiber mixture and the other group received a placebo (maltodextrin). The primary outcome was therapeutic failure (oral stool softeners or enemas was required to prescribe during the trial). Secondary outcomes included defecation frequency, stool consistency (measured using the Bristol Stool Form Scale), and CTT. RESULTS: Therapeutic failure was observed in 34.6% (9/26) of the patients in the dietary fiber mixture group and in 35.7% (10/28) in the control group (P = 0.933). The mean increase in daily bowel movements was 0.53 in the dietary fiber mixture group and 0.23 in the control group (P = 0.014). The patients in the dietary fiber mixture group (60.0%) passed nonhardened stools more frequently than did those in the control group (16.7%, P = 0.003). The CTT was similar for both groups. CONCLUSIONS: The fiber mixture did not prevent the suspension of stool softeners or lead to reduced CTT; however, the mixture promoted an increased frequency of defecation and an improvement in the stool consistency.

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

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.

Lactose malabsorption, calcium intake, and bone mass in children and adolescents.

OBJECTIVES: The objective of the present study was to evaluate the calcium intake and bone mass in children and early adolescents in accordance with their absorption capacity to lactose. PATIENTS AND METHODS: A transversal study was conducted on a sample composed of 76 individuals. Lactose malabsorption status was determined with hydrogen breath test. The hydrogen breath test was applied using 2  g of lactose per kilogram of weight up to a maximum of 50  g. A hydrogen increment ≥20  pm in relation to fasting was used to characterize lactose malabsorption. Two 24-hour recalls were applied for the evaluation of food consumption. Bone mineral content and bone mineral density were evaluated in the lumbar spine by dual-energy x-ray absorptiometry. RESULTS: The prevalence of lactose malabsorption was 61.8%. The participants were divided into 2 groups: lactose malabsorbers (n = 47) and lactose absorbers (n = 29). There was no statistically significant difference (P > 0.05) between the groups with respect to the intake of total calcium, milk calcium, milk, cheese, yogurt, ice cream, and calcium density of the diet. Additionally, there was no difference with respect to the bone mineral content and the bone mineral density of the lumbar spine. Independent from lactose absorption capacity, it was observed that the majority of the children and early adolescents showed calcium intake lower than the recommended value. CONCLUSIONS: There was no relation among lactose malabsorption and bone densities, bone mineral content, or calcium intake within the present study.

Gut microbiota comparison of vaginally and cesarean born infants exclusively breastfed by mothers secreting α1-2 fucosylated oligosaccharides in breast milk.

BACKGROUND: Exclusive breastfeeding promotes beneficial modifications on the microbiota of cesarean born infants, but little is known about the role of specific breast milk components in this modulation. Women with an active FUT2 gene (called secretors) secrete α1-2 fucosylated human milk oligosaccharides (HMOs), which promote Bifidobacterium in the infant's gut and may modulate the microbiota of cesarean born infants. OBJECTIVE: To compare the microbiota composition of cesarean and vaginally born infants breastfed by secretor mothers. METHODS: Maternal secretor status was determined by the occurrence of 4 different α1-2 fucosylated HMOs in breast milk by LC-MS. The fecal microbiota composition from cesarean and vaginally born infants was analyzed by 16S rRNA gene sequencing and qPCR, stratified by the maternal secretor status, and compared. RESULTS: Alpha and beta diversity were not significantly different in cesarean born, secretor-fed infants (CSe+) compared to vaginally born, secretor-fed infants (VSe+). There were no significant differences in the fecal relative abundance of Bifidobacterium between CSe+ and VSe+ infants, but the prevalence of the species B. longum was lower in CSe+. The fecal relative abundance of Bacteroides was also lower, while Akkermansia and Kluyvera were higher in CSe+ infants. CONCLUSION: Cesarean and vaginally born infants fed with breast milk containing the α1-2 fucosylated HMOs fraction present similar amounts of Bifidobacterium in the feces, but differences are observed in other members of the microbiota.

Validation and application of a method for the simultaneous absolute quantification of 16 neutral and acidic human milk oligosaccharides by graphitized carbon liquid chromatography - electrospray ionization - mass spectrometry.

Human milk oligosaccharides (HMOs) are free glycans naturally present in human milk that act as prebiotics, prevent pathogen binding, modulate the immune system and support brain development in infants. The HMOs composition and concentrations vary significantly among different women mainly because of the direct influence of the Secretor and Lewis phenotypes on HMOs biosynthesis. Analytical methods that can identify the differences in the HMOs composition and concentrations are a fundamental tool in HMOs research. This paper describes a simple HMOs extraction and analysis for the simultaneous and absolute quantification of neutral and acidic HMOs by graphitized carbon liquid chromatography-electrospray ionization-mass spectrometry. This method was validated and applied to analyze HMOs in the human milk obtained from 10 women. This method allows accurate and reliable quantification of HMOs and can be used to determine differences in HMOs concentrations throughout lactation and among women with different Secretor and Lewis phenotypes.