Fecal Microbiota Of Children Research Articles

Effect of ursodeoxycholic acid on the intestinal microbiota in children with chronic liver disease

Ursodeoxycholic acid is a secondary bile acid (BA), present in humans at low concentrations, with well-known therapeutic properties, and was originally used to treat cholestatic liver disease. However, there are very few studies on the effect of ursodeoxycholic acid on the composition of the gut microbiota, especially in children with chronic liver diseases.Purpose. To determine differences in the taxonomic diversity of the fecal microbiota in children with chronic liver disease who receive or do not receive ursodeoxycholic acid.Material and methods. A metagenomic analysis of the intestinal microbiota of 24 children with chronic liver diseases (mean age 10.3 ± 4.7 years) was carried out with the identification of the V3–V4 region of the 16S rRNA gene. The group included 18 children with autoimmune liver diseases and 6 children with non-autoimmune liver diseases. 17 children received ursodeoxycholic acid. The comparison group consisted of 7 children who did not receive ursodeoxycholic acid.Results. This study found that fecal samples from patients treated with ursodeoxycholic acid do not differ in the taxonomic diversity of the gut microbiota from samples from patients not treated with ursodeoxycholic acid. A more detailed study to determine the existing taxonomic diversity in samples of patients treated with ursodeoxycholic acid and not treated with ursodeoxycholic acid, using the sPLS-DA method, showed that taxa such as Streptococcus anginosus, Coprococcus eutactus, Desulfovibrio desulfuricans, Angelakisella massiliensis and Gemella haemolysans dominated in patients not treated with ursodeoxycholic acid. And for patients receiving drugs with ursodeoxycholic acid, the dominance of the taxon Anaerostipes hadrus is typical. An analysis of differences in the percentage of intestinal microbiota bacterial species showed that patients receiving ursodeoxycholic acid had a higher count of Anaerostipes hadrus, while in patients not receiving ursodeoxycholic acid preparations, the count of Bacteroides dorei, Akkermansia muciniphila was significantly increased, and the counts of other bacteria were also increased.Conclusion. Studies have shown that ursodeoxycholic acid has a positive effect on the intestinal microbiota in children with chronic liver disease by increasing the number of microorganisms that produce short-chain fatty acids.

Gut microbiota in chronic liver diseases in children

The impact of gut microbiota on the development of various diseases is of great interest to researchers. However, data on the taxonomic diversity of the intestinal microbiota in chronic liver diseases in children are lacking.Purpose. To study the taxonomic diversity of the fecal microbiota in children with chronic liver diseases in comparison with healthy patients.Material and methods. A metagenomic analysis of the intestinal microbiota of 24 children with chronic liver diseases (mean age 10.3 ± 4.7 years) was carried out with the isolation of the target fragment of the 16S rRNA gene. The group included 18 children with autoimmune liver diseases and 6 children with non-autoimmune liver diseases. The comparison group consisted of fecal samples of 34 apparently healthy children.Results. The conducted study revealed 684 types of microorganisms in the studied samples of patients’ feces. An analysis of the conducted studies showed that fecal samples of healthy children and patients with chronic liver diseases differ in bacterial diversity. The dominant taxa in healthy children were Neisseria flavescens, in patients with chronic liver diseases, the dominant taxa were Bifidobacterium longum, Bifidobacterium adolescentis, Blautia massiliensis. At the same time, Bifidobacterium longum, Bifidobacterium adolescentis, Blautia massiliensis in fecal samples of patients with chronic liver diseases was 8 times as high.Conclusion. Studies have shown differences in the composition of the intestinal microbiota in healthy children and children with chronic liver diseases.

Characterization of the oral and gut microbiome in children with obesity aged 3 to 5 years.

The ever-increasing global prevalence of obesity has trended towards a younger age. The ecological characteristics and changes of the oral and gut microbial community during childhood are poorly understood.In this study, we analyzed the salivary and fecal microbiota of 30 children with obesity and 30 normal weight children aged 3-5 years via third-generation long-range DNA sequencing,with the aim of understanding the structure of childhood microbiota and identifying specific oral and gut microbial lineages and genera in children that may be associated with obesity.The results revealed significant variation in alpha diversity indices among the four groups (Chao1: P < 0.001; observed species: P < 0.001; Shannon < 0.001). Principal coordinate analysis (PCoA) and nonmetric multidimensional scaling (NMDS) revealed significant differences in oral and gut microbial community structure between obesity and controls. The Firmicutes/Bacteroidetes (F/B) abundance ratios of oral and intestinal flora among children with obesity were higher than those of controls. The most abundant phyla and genera found in oral and intestinal flora were Firmicutes, Proteobacteria, Bacteroidetes, Neisseria, Bacteroides, Faecalibacterium, Streptococcus, Prevotella and so on. Linear discriminant analysis effect size (LEfSe) revealed higher proportions of Filifactor (LDA= 3.98; P < 0.05) and Butyrivibrio (LDA = 2.54; P < 0.001) in the oral microbiota of children with obesity, while the fecal microbiota of children with obesity were more enriched with Faecalibacterium (LDA = 5.02; P < 0.001), Tyzzerella (LDA=3.25; P < 0.01), Klebsiella (LDA = 4.31; P < 0.05),which could be considered as dominant bacterial biomarkers for obesity groups.A total of 148 functional bacterial pathways were found to significantly differ in the oral and gut microbiota among controls and obesity using PICRUSt 2. Most predicted functional pathways were clustered in biosynthesis. In conclusion, This work suggests there were significant differences in oral and gut microbiota in controls and obesity groups, microbiota dysbiosis in childhood might have significant effect on the development of obesity.

Is there a difference in fecal microbiota of children with and without voiding dysfunction?

Voiding dysfunction (VD), which encompasses many urinary symptoms that are not caused by neurological or anatomical anomalies, is a frequently encountered functional urinary bladder disorder in children. It was reported that there was an association between lower urinary tract symptoms and fecal microbiota in adult patients. Therefore, we aimed to investigate the differences in fecal microbiota between children with or without VD. Two patient groups, including 30 patients, were compared. Group 1 included patients with VD, while Group 2 consisted of healthy children. All study participants were asked to fill lower urinary tract and voiding dysfunction symptom score forms with the assistance of their parents. Subsequently, uroflowmetry tests and postvoiding residual urine measurements were performed. Fresh stool samples were collected from all children and analyzed by polymerase chain reaction. General bacterial load and presence of Roseburia intestinalis, Clostridium difficile, Fusobacterium nucleatum, and Bacteroides clarus were tested. The two groups were significantly different regarding general bacterial load; the presence of Fusobacterium nucleatum. Clostridium difficile and Bacteroides clarus was not detected in the fresh stool samples of the patients in Group 2; the counts of Roseburia intestinalis were less in Group 1 than in Group 2, although there was no statistically significant difference. There was a negative correlation between symptom scores, general bacterial load, and the presence of Fusobacterium nucleatum. However, there was no correlation between the presence of Roseburia intestinalis and symptom scores. There is a potential relationship between VD and a deviation in the fecal microbiota in the pediatric population.

Fecal microbiota in children with juvenile idiopathic arthritis treated with methotrexate or etanercept

BackgroundAlterations in the composition of the fecal microbiota in children with juvenile idiopathic arthritis (JIA) have been observed in several studies, but it has not been determined whether the standard treatment for JIA changes the composition or function of the microbiota.The first-line disease-modifying anti-rheumatic drug for treatment of JIA is usually methotrexate, followed or supplemented by anti-tumor necrosis factor alpha drugs, such as etanercept. The aim of this study was to investigate the effects of methotrexate and etanercept treatments on the fecal microbiota and the fecal short-chain fatty acids (SCFAs) in children with JIA.MethodsIn this multicenter study, the composition of fecal microbiota from 45 treatment-naïve children with JIA was compared with that from 29 children treated with methotrexate and 12 children treated with etanercept. We also made pairwise comparisons of 15 children sampled before and during methotrexate treatment and 7 children sampled before and during etanercept treatment.The microbiota was determined using sequencing amplicons from the V3 and V4 regions of the 16S rRNA gene. Alpha-diversity, community composition, and relative abundances of bacterial taxa were analyzed in all comparisons. Analyses of fecal SCFAs, using a high-performance liquid chromatograph, were performed for the pairwise comparisons.ResultsWe did not find any significant differences in α-diversity or community composition of microbiota. However, principal coordinate analysis indicated a change in community composition in 7 of the 15 paired samples before and during methotrexate and 2 of the 7 paired samples before and during etanercept.Comparisons of the relative abundance of taxa revealed minor differences before and during treatment with methotrexate or etanercept, but they were not significant after correction for multiple analyses, and the unpaired and paired analyses did not show similar changes.There were no significant differences in levels of fecal SCFAs before and during treatment with methotrexate or etanercept.ConclusionsTreatment with methotrexate or etanercept had minor, but no significant or consistent changes either on composition of microbiota or on levels of SCFAs, suggesting that these changes are not related to the therapeutic effects of methotrexate or etanercept.

Fecal Microbiota in Untreated Children With Juvenile Idiopathic Arthritis: A Comparison With Healthy Children and Healthy Siblings.

Changes in the composition of gut microbiota have been suggested to be associated with juvenile idiopathic arthritis (JIA). The objective in this study was to investigate if the diversity and composition of the fecal microbiota differed between children with JIA and healthy controls (HCs), and if the microbiota differed between children with JIA and their healthy siblings. In this multicenter, case-control study, fecal samples were collected from 75 children with JIA and 32 HCs. Eight of the HCs were siblings to 8 children with JIA, and they were compared only pairwise with their siblings. The microbiota was determined using sequencing amplicons from the V3 and V4 regions of the 16S rRNA gene. Alpha diversity, community composition of microbiota, and relative abundances of taxa were compared between children with JIA and healthy unrelated controls as well as between children with JIA and healthy siblings. Our data revealed no significant differences in α-diversity or community composition of microbiota between children with JIA, healthy unrelated controls, or healthy siblings. Analyses of relative abundances of phyla, families, and genera identified trends of differing abundances of some taxa in children with JIA, in comparison with both HCs and healthy siblings, but none of these findings were significant after adjustment for multiple comparisons. There were no significant differences in the composition of fecal microbiota in children with JIA compared with HCs. The composition of microbiota in children with JIA did not differ significantly from that in their healthy siblings.

A comparison of small bowel and fecal microbiota in children with short bowel syndrome

BackgroundBabies with short bowel syndrome (SBS) have small intestinal microbial disturbances that impact gut function. Characterizing the small bowel microbiota is challenging, and the utility of sampling stool is unclear. This study compares the microbiota from fecal samples and the small bowel. MethodsStool samples were collected (2016–2017) from infants with SBS and colon in continuity (COLON) or SBS with small bowel ostomy (sbSTOMA). The abundance and quantity of major bacterial genera was compared between groups and to healthy controls using 16S rRNA sequencing and qPCR. Kruskall-Wallis test was used for analysis with P values <0.05 considered significant. ResultsSamples (n = 41) were collected from 15 SBS infants (<2 years) (9 sbSTOMA, 6 COLON) and 3 healthy infants. Demographics and small intestinal length did not differ between sbSTOMA and COLON infants. The microbiota of SBS groups differed significantly from healthy controls. Fecal samples contained higher quantities of bacteria, but there were no significant differences between sbSTOMA and COLON groups in the abundance of facultative or obligate anaerobes, anti-inflammatory Clostridia, Enterobacteriaceae, or Bifidobacterium. ConclusionInfants with SBS have disturbances to their intestinal microbiota. Sampling small intestinal effluent is challenging. Stool samples may provide a window into the more proximal microbial community. Type of StudyDiagnostic. Level of EvidenceLevel II.

Alteration of the gut microbiota associated with childhood obesity by 16S rRNA gene sequencing.

BackgroundObesity is a global epidemic in the industrialized and developing world, and many children suffer from obesity-related complications. Gut microbiota dysbiosis might have significant effect on the development of obesity. The microbiota continues to develop through childhood and thus childhood may be the prime time for microbiota interventions to realize health promotion or disease prevention. Therefore, it is crucial to understand the structure and function of pediatric gut microbiota.MethodsAccording to the inclusion criteria and exclusion criteria, twenty-three normal weight and twenty-eight obese children were recruited from Nanjing, China. Genomic DNA was extracted from fecal samples. The V4 region of the bacterial 16S rDNA was amplified by PCR, and sequencing was applied to analyze the gut microbiota diversity and composition using the Illumina HiSeq 2500 platform.ResultsThe number of operational taxonomic units (OTUs) showed a decrease in the diversity of gut microbiota with increasing body weight. The alpha diversity indices showed that the normal weight group had higher abundance and observed species than the obese group (Chao1: P < 0.001; observed species: P < 0.001; PD whole tree: P < 0.001; Shannon index: P = 0.008). Principal coordinate analysis (PCoA) and Nonmetric multidimensional scaling (NMDS) revealed significant differences in gut microbial community structure between the normal weight group and the obese group. The liner discriminant analysis (LDA) effect size (LEfSe) analysis showed that fifty-five species of bacteria were abundant in the fecal samples of the normal weight group and forty-five species of bacteria were abundant in the obese group. In regard to phyla, the gut microbiota in the obese group had lower proportions of Bacteroidetes (51.35%) compared to the normal weight group (55.48%) (P = 0.030). There was no statistical difference in Firmicutes between the two groups (P = 0.436), and the Firmicutes/Bacteroidetes between the two groups had no statistical difference (P = 0.983). At the genus level, Faecalibacterium, Phascolarctobacterium, Lachnospira, Megamonas, and Haemophilus were significantly more abundant in the obese group than in the normal weight group (P = 0.048, P = 0.018, P < 0.001, P = 0.040, and P = 0.003, respectively). The fecal microbiota of children in the obese group had lower proportions of Oscillospira and Dialister compared to the normal weight group (P = 0.002 and P = 0.002, respectively).ConclusionsOur results showed a decrease in gut microbiota abundance and diversity as the BMI increased. Variations in the bacterial community structure were associated with obesity. Gut microbiota dysbiosis might play a crucial part in the development of obesity in Chinese children.

Analysis of gut microbiota profiles and microbe-disease associations in children with autism spectrum disorders in China

Autism spectrum disorder (ASD) is a set of complex neurodevelopmental disorders. Recent studies reported that children with ASD have altered gut microbiota profiles compared with typical development (TD) children. However, few studies on gut bacteria of children with ASD have been conducted in China. Here, in order to elucidate changes of fecal microbiota in children with ASD, 16S rRNA sequencing was conducted and the 16S rRNA (V3-V4) gene tags were amplified. We investigated differences in fecal microbiota between 35 children with ASD and 6 TD children. At the phylum level, the fecal microbiota of ASD group indicated a significant increase of the Bacteroidetes/Firmicutes ratio. At the genus level, we found that the relative abundance of Sutterella, Odoribacter and Butyricimonas was much more abundant in the ASD group whereas the abundance of Veillonella and Streptococcus was decreased significantly compared to the control group. Functional analysis demonstrated that butyrate and lactate producers were less abundant in the ASD group. In addition, we downloaded the association data set of microbe–disease from human microbe–disease association database and constructed a human disease network including ASD using our gut microbiome results. In this microbe–disease network based on microbe similarity of diseases, we found that ASD is positively correlated with periodontal, negatively related to type 1 diabetes. Therefore, these results suggest that microbe-based disease analysis is able to predict novel connection between ASD and other diseases and may play a role in revealing the pathogenesis of ASD.

Fecal microbiota analysis of children with small intestinal bacterial overgrowth among residents of an urban slum in Brazil

ObjectiveTo analyze the fecal microbiota composition of children living in an urban slum in Brazil, with or without small intestinal bacterial overgrowth, and to investigate the occurrence of stunting and anemia. MethodsA total of 100 children were studied, aged 5–11 years, from the municipality of Osasco, São Paulo. Small intestinal bacterial overgrowth was screened through hydrogen and methane breath test with lactulose. Weight and height were measured, and the height‐for‐age and body mass‐for‐age anthropometric indexes were calculated. The occurrence of anemia was investigated by capillary hemoglobin. Analysis of bacterial phylum, genus, and species was performed by real‐time polymerase chain reaction in fecal samples. ResultsSmall intestinal bacterial overgrowth was identified in 61.0% of the children. A lower mean of height‐for‐age Z‐score ([−0.48±0.90] vs. [−0.11±0.97]; p=0.027), as well as capillary hemoglobin ([12.61±1.03g/dL] vs. [13.44±1.19g/dL]; p<0.001) was demonstrated in children with SIBO when compared with children without small intestinal bacterial overgrowth. Children with small intestinal bacterial overgrowth presented a higher frequency of Salmonella spp., when compared to those without small intestinal bacterial overgrowth (37.7% vs. 10.3%; p=0.002). Higher counts of total Eubacteria (p=0.014) and Firmicutes (p=0.038) were observed in children without small intestinal bacterial overgrowth; however, a higher count of Salmonella (p=0.002) was found in children with small intestinal bacterial overgrowth. ConclusionChildren who lived in a slum and were diagnosed with small intestinal bacterial overgrowth showed lower H/A Z‐scores and hemoglobin levels. Furthermore, differences were observed in the fecal microbiota of children with small intestinal bacterial overgrowth, when compared to those without it; specifically, a higher frequency and count of Salmonella, and lower counts of Firmicutes and total Eubacteria.

New insights into the fecal microbiota of children living in a slum: association with small bowel bacterial overgrowth

New insights into the fecal microbiota of children living in a slum: association with small bowel bacterial overgrowth

Characterization of Fecal Microbiota, Short-Chain Fatty Acids and Lactic Acid Concentrations in 5 - 8-Year-Old Children with Cow Milk Protein Allergy

Background: Cow milk protein allergy (CMPA) has been reported to be associated with the alterations of gut microbiota. However, changes in the fecal microbial community for children aged 5 - 8 years with CMPA have not been clearly elucidated. Objectives: The aim of the study is to assess the differences and relationship between fecal microbiota and levels of fecal short-chain fatty acids (SCFAs) and lactic acid in 5 - 8-year-old children with CMPA, compared with the normal children. Methods: We enrolled 6 CMPA children and 8 healthy children from Harbin children’s hospital (Heilongjiang, China). Total bacterial DNA of all fecal samples was extracted and prepared for bioinformatics analysis by 16S rDNA amplicon sequencing. Lactic acids and SCFAs were measured by the high-performance liquid chromatography (HPLC) technique. Results: Compared with healthy individuals, the fecal microbial community of CMPA children showed a significant increment of Firmicutes and depletion of Proteobacteria (P < 0.05). At the class level, the number of Clostridia was observed to be significantly increased in the CMPA children’s fecal microbiota. Meanwhile, the diversity of Ruminococcaceae and Subdoligranulum was higher in the fecal microbiome of CMPA children than in healthy children (P < 0.05). Furthermore, linear discriminant analysis of effect size (LEfSe) revealed some significantly enriched taxa of CMPA children and control subjects. There are 40 and 5 enriched taxa in the fecal microbiota of children with CMPA and healthy children respectively. The concentration of total SCFAs was lower in feces of CMPA children than in healthy children. Lactic acid had a significantly negative correlation with the abundance of Bacteroides. Conclusions: Alterations in the composition of fecal microbiota and SCFAs in the 5 - 8-year-old children with CMPA may reduce immune function and potentially promote this allergy.

Fecal microbiota analysis of children with small intestinal bacterial overgrowth among residents of an urban slum in Brazil

ObjectiveTo analyze the fecal microbiota composition of children living in an urban slum in Brazil, with or without small intestinal bacterial overgrowth, and to investigate the occurrence of stunting and anemia. MethodsA total of 100 children were studied, aged 5–11 years, from the municipality of Osasco, São Paulo. Small intestinal bacterial overgrowth was screened through hydrogen and methane breath test with lactulose. Weight and height were measured, and the height-for-age and body mass-for-age anthropometric indexes were calculated. The occurrence of anemia was investigated by capillary hemoglobin. Analysis of bacterial phylum, genus, and species was performed by real-time polymerase chain reaction in fecal samples. ResultsSmall intestinal bacterial overgrowth was identified in 61.0% of the children. A lower mean of height-for-age Z-score ([−0.48±0.90] vs. [−0.11±0.97]; p=0.027), as well as capillary hemoglobin ([12.61±1.03g/dL] vs. [13.44±1.19g/dL]; p<0.001) was demonstrated in children with SIBO when compared with children without small intestinal bacterial overgrowth. Children with small intestinal bacterial overgrowth presented a higher frequency of Salmonella spp., when compared to those without small intestinal bacterial overgrowth (37.7% vs. 10.3%; p=0.002). Higher counts of total Eubacteria (p=0.014) and Firmicutes (p=0.038) were observed in children without small intestinal bacterial overgrowth; however, a higher count of Salmonella (p=0.002) was found in children with small intestinal bacterial overgrowth. ConclusionChildren who lived in a slum and were diagnosed with small intestinal bacterial overgrowth showed lower H/A Z-scores and hemoglobin levels. Furthermore, differences were observed in the fecal microbiota of children with small intestinal bacterial overgrowth, when compared to those without it; specifically, a higher frequency and count of Salmonella, and lower counts of Firmicutes and total Eubacteria.

Enterotoxigenic and non-enterotoxigenic Bacteroides fragilis from fecal microbiota of children.

Enterotoxigenic Bacteroides fragilis (ETBF) is an important part of the human and animal intestinal microbiota and is commonly associated with diarrhea. ETBF strains produce an enterotoxin encoded by the bft gene located in the B. fragilis pathogenicity island (BfPAI). Non-enterotoxigenic B. fragilis (NTBF) strains lack the BfPAI and usually show two different genetic patterns, II and III, based on the absence or presence of a BfPAI-flanking region, respectively. The incidence of ETBF and NTBF strains in fecal samples isolated from children without acute diarrhea or any other intestinal disorders was determined. All 84 fecal samples evaluated were B. fragilis-positive by PCR, four of them harbored the bft gene, 27 contained the NTBF pattern III DNA sequence, and 52 were considered to be NTBF pattern II samples. One sample was positive for both ETBF and NTBF pattern III DNA sequences. All 19 B. fragilis strains isolated by the culture method were bft-negative, 9 belonged to pattern III and 10 to pattern II. We present an updated overview of the ETBF and NTBF incidence in the fecal microbiota of children from Sao Paulo City, Brazil.

Gastrointestinal microbiota in children with autism in Slovakia

Development of Autism Spectrum Disorders (ASD), including autism, is based on a combination of genetic predisposition and environmental factors. Recent data propose the etiopathogenetic role of intestinal microflora in autism. The aim of this study was to elucidate changes in fecal microbiota in children with autism and determine its role in the development of often present gastrointestinal (GI) disorders and possibly other manifestations of autism in Slovakia. The fecal microflora of 10 children with autism, 9 siblings and 10 healthy children was investigated by real-time PCR. The fecal microbiota of autistic children showed a significant decrease of the Bacteroidetes/Firmicutes ratio and elevation of the amount of Lactobacillus spp. Our results also showed a trend in the incidence of elevated Desulfovibrio spp. in children with autism reaffirmed by a very strong association of the amount of Desulfovibrio spp. with the severity of autism in the Autism Diagnostic Interview (ADI) restricted/repetitive behavior subscale score. The participants in our study demonstrated strong positive correlation of autism severity with the severity of GI dysfunction. Probiotic diet supplementation normalized the Bacteroidetes/Firmicutes ratio, Desulfovibrio spp. and the amount of Bifidobacterium spp. in feces of autistic children. We did not find any correlation between plasma levels of oxytocin, testosterone, DHEA-S and fecal microbiota, which would suggest their combined influence on autism development. This pilot study suggests the role of gut microbiota in autism as a part of the “gut-brain” axis and it is a basis for further investigation of the combined effect of microbial, genetic, and hormonal changes for development and clinical manifestation of autism.

Differences in the faecal microbiota of children with β-cell autoimmunity

Differences in the faecal microbiota of children with β-cell autoimmunity

Predominant genera of fecal microbiota in children with atopic dermatitis are not altered by intake of probiotic bacteria Lactobacillus acidophilus NCFM and Bifidobacterium animalis subsp. lactis Bi-07

The effect of probiotic bacteria Lactobacillus acidophilus NCFM and Bifidobacterium lactis Bi-07 on the composition of the Lactobacillus group, Bifidobacterium and the total bacterial population in feces from young children with atopic dermatitis was investigated. The study included 50 children randomized to intake of one of the probiotic strain or placebo. Microbial composition was characterized by denaturing gradient gel electrophoresis, quantitative PCR and, in a subset of subjects, by pyrosequencing of the 16S rRNA gene. The core population of the Lactobacillus group was identified as Lactobacillus gasseri, Lactobacillus fermentum, Lactobacillus oris, Leuconostoc mesenteroides, while the bifidobacterial community included Bifidobacterium adolescentis, Bifidobacterium bifidum, Bifidobacterium longum and Bifidobacterium catenulatum. The fecal numbers of L. acidophilus and B. lactis increased significantly after intervention, indicating survival of the ingested bacteria. The levels of Bifidobacterium correlated positively (P=0.03), while the levels of the Lactobacillus group negatively (P=0.01) with improvement of atopic eczema evaluated by the Severity Scoring of Atopic Dermatitis index. This correlation was observed across the whole study cohort and not attributed to the probiotic intake. The main conclusion of the study is that administration of L. acidophilus NCFM and B. lactis Bi-07 does not affect the composition and diversity of the main bacterial populations in feces.

Distribution, detection of enterotoxigenic strains and antimicrobial drug susceptibility patterns of Bacteroides fragilis group in diarrheic and non-diarrheic feces from Brazilian infants

Despite the importance of gastrointestinal diseases and their global distribution, affecting millions of individuals around the world, the role and antimicrobial susceptibility patterns of anaerobic bacteria such as those in the Bacteroides fragilis group (BFG) are still unclear in young children. This study investigated the occurrence and distribution of species in the BFG and enterotoxigenic strains in the fecal microbiota of children and their antimicrobial susceptibility patterns. Diarrheic (n=110) and non-diarrheic (n=65) fecal samples from children aged 0–5 years old were evaluated. BFG strains were isolated and identified by conventional biochemical, physiological and molecular approaches. Alternatively, bacteria and enterotoxigenic strains were detected directly from feces by molecular biology. Antimicrobial drug susceptibility patterns were determined by the agar dilution method according to the guidelines for isolated bacteria. BFG was detected in 64.3% of the fecal samples (55% diarrheic and 80.4% non-diarrheic), and 4.6% were enterotoxigenic. Antimicrobial resistance was observed against ampicillin, ampicillin/sulbactam, piperacillin/tazobactam, meropenem, ceftriaxone, clindamycin and chloramphenicol. The data show that these bacteria are prevalent in fecal microbiota at higher levels in healthy children. The molecular methodology was more effective in identifying the B. fragilis group when compared to the biochemical and physiological techniques. The observation of high resistance levels stimulates thoughts about the indiscriminate use of antimicrobial drugs in early infancy. Further quantitative studies are needed to gain a better understanding of the role of these bacteria in acute diarrhea in children.

Gut Microbiota of Children Living in Rural South Thailand and Urban Singapore

An imbalanced prevalence of allergic diseases occurs in the region of South East Asia. It has been suggested that a change in lifestyle associated with improved hygiene and modernization has altered the composition of human gastrointestinal microbiota, and hence susceptibility to allergy. This cross-sectional study was designed to investigate the differences between fecal microbiota in children living in areas with contrasting socioeconomic development. Fecal samples from 73 young children (age 3.0 +/- 0.5) from rural Thailand and 69 age-matched children from urban Singapore were collected and studied using selective culture. Clinical data were also collected using modified ISAAC questionnaires, aiming to identify the key differences in the demographic as well as clinical features between the two study groups. The two contrasting populations studied differed significantly in multiple lifestyle factors such as family size, antibiotic use and sources of drinking water in the households. Rural children harbored significantly higher counts of lactic acid bacteria (LAB) [7.1 (6.4, 8.3) vs 6.0 (5.3, 7.0) logCFU/g, p < 0.001)], coliforms [8.9 (7.3, 10.2) vs 6.9 (5.7, 7.7) logCFU/g, p < 0.001)] as well as staphylococci [5.3 (4.8, 6.3) vs 4.3 (3.6, 5.0) logCFU/g, p < 0.001)] than their urban counterparts. However, enterococcal counts did not differ between the two groups. No single lifestyle factor could be identified to have caused such differences. Certain fecal microbial counts were higher in rural children compared with urban children in South East Asia. Several contrasting home environmental conditions and practices were also identified. These may serve as a basis for future investigation of lifestyle factors underlying the global gradient of the increasing trends of allergic diseases.

Variation in human intestinal microbiota with age

The large intestinal microbiota plays an important role in normal bowel function and the maintenance of host health, through the formation of short chain fatty acids, modulation of immune system reactivity and development of colonisation resistance. However, the effects of ageing on bacterial community structure in the colon are not well documented. Aim of this study is to assess bacterial species diversity in the human faecal microbiota with respect to age and Clostridium difficile infection. Bacterial populations were quantified from stool samples obtained from children (16 months to seven years), young adults (21–34 years), healthy elderly people (67–88 years) and patients diagnosed with Clostridium difficile-associated diarrhoea (68–73 years). Microbial diversity was assessed to species level for samples from the latter three subject groups. Marked interindividual variations occurred in microbial composition at genus and species levels. The faecal microbiota of children was found to be bacteriologically less complex whilst advancing age was associated with decreased bifidobacteria and increased bacteroides species diversity. Changes in microbial composition with age or disease will alter the metabolic capacity of the gut microbiota and has important implications for therapies aimed at modulating the large intestinal microbiota.