Differences In Fecal Microbiota Research Articles

Gut Microbiota Dysbiosis in Patients with Biopsy-Proven Nonalcoholic Fatty Liver Disease: A Cross-Sectional Study in Taiwan.

The gut microbiota plays a role in nonalcoholic fatty liver disease (NAFLD), but data about gut dysbiosis in Asians with NAFLD remains scarce. We analyzed the differences in fecal microbiota between adults with and without NAFLD. This cross-sectional study examined adults with histology-proven NAFLD (25 nonalcoholic fatty liver (NAFL) patients, 25 nonalcoholic steatohepatitis (NASH) patients, and 25 living liver donors (healthy controls)). The taxonomic composition of the gut microbiota was determined by 16S ribosomal RNA gene sequencing of stool samples. The NAFL and NASH groups showed lower total bacterial diversity and richness than the controls. NAFLD patients had higher levels of the phylum Bacteroidetes and lower levels of Firmicutes than controls. The genus Ruminococcaceae UCG-010, family Ruminococcaceae, order Clostridiales, and class Clostridia were less abundant in patients with NAFL or NASH than healthy individuals. The lipopolysaccharide biosynthesis pathway was differentially enriched in the NASH group. This study examined the largest number of Asian patients with biopsy-proven NAFL and NASH in terms of dysbiosis of the gut microbiota in NAFLD patients. NAFLD patients had higher levels of Bacteroidetes and lower levels of Firmicutes. These results are different from research from western countries and could provide different targets for therapies by region.

Fecal Microbiota, Lactic Acid and Short Chain Fatty Levels of Infants Following Rotavirus Infection Revealed by Illumina Miseq High-Throughput Sequencing and HPLC Method

Background: Rotavirus (RV) is one of the major causes of acute gastroenteritis in infants. It is indispensable to demonstrate the relationship between the diversity and richness of gut microbiota and RV infection using more accurate and effective technology. Objectives: To investigate the differences in fecal microbiota, lactic acid, and short-chain fatty acids (SCFAs) levels between rotaviral-induced diarrhea (RD) infants and healthy (H) infants. Methods: The infants comprised of 25 infants aged few days to six months, who were in good health (n = 12) or diagnosed with rotavirus (n = 13). Fecal matter was analyzed with Illumina Miseq high-throughput sequencing technique targeting the 16s rRNA gene V3-V4 region. Lactic acids and SCFAs were measured by the high-performance liquid chromatography (HPLC) technique. Results: Compared to H infants, the fecal samples in RD infants had lower Shannon diversity index and the bacteria richness (P < 0.05). A higher proportion of Proteobacteria, Enterobacteriaceae and Klebsiella, and lower abundances of Actinobacteria and Knoellia (P < 0.05) were detected in fecal samples of RD infants. The total SCFAs content of fecal samples showed no distinction between RD and H infants, yet lower levels of lactic acid were observed in fecal samples of RD infants. Conclusions: Rotaviral infection in infants led to an alteration of fecal microbiota and lactic acid concentration compared with healthy infants. Fecal microbiota and metabolite may advance the understanding and treatment of RD.

Abstract 3585: Amino acid transporter SLC6A14: A novel drug target for colorectal cancer

Abstract SLC6A14 is a Na+/Cl− -dependent amino acid transporter capable of transporting 18 of the 20 proteinogenic amino acids, including arginine, leucine (mTOR activators) and glutamine (necessary for nucleotide biosynthesis). This transporter is expressed at basal levels in normal colon but significantly upregulated in colorectal cancer (CRC). However, the relevance of this upregulation to disease progression remains unknown. We postulated that deletion of SLC6A14 or pharmacological blockade of its function would suppress CRC by depleting amino acids and interfering with mTOR signaling selectively in tumor cells. To test this postulate, we first used Slc6a14-null mice. With two different models of spontaneous CRC (Apcmin/- and DSS/AOM), we found the tumor incidence and tumor growth were much lower in mice with Slc6a14-null background than in mice with Slc6a14. To evaluate the impact of pharmacologic blockade of the transporter on tumor growth we used a syngeneic tumor mouse model with MC-38 cells (a mouse CRC cell line); blockade of Slc6a14 with alpha-methyl tryptophan (α-MT) markedly reduced tumor growth. We then determined the transcriptome profiles of colonic epithelial cells and colonic non-epithelial cells from wild type mice and Slc6a14-null mice by RNAseq. There were hundreds of genes that were either upregulated or downregulated in the null mice. Ingenuity pathway analysis (IPA) of these data revealed predictive activation of canonical AMPK signaling pathway in colonic epithelial of Slc6a14-null mice. AMPK has anticancer activities by modulating multiple pathways including negatively regulating mTOR signaling. Moreover, upstream analysis showed predictive inactivation of two important tumor growth and survival signaling pathways ERK and EGF in the colon of the null mice. Likewise, significant upregulation of APC downregulated 1 (APCDD1) in epithelial cells in null mice implies predictive suppression of canonical Wnt signaling pathway. We also found marked differences in fecal microbiota as a result of Slc6a14 deletion. There was an increase in the relative abundance of beneficial microbiota including those capable of generating short chain fatty acids and lactic acid in null mice. We conclude that deletion of Slc6a14 or its pharmacological blockade protects against CRC by inducing amino acid starvation in tumor cells, thereby causing changes in multiple signaling pathways and in colonic microbiome. These studies identify SLC6A14 as a novel drug target for the treatment of colorectal cancer. Citation Format: Mohd Omar Faruk Sikder, Sathish Sivaprakasam, Vadivel Ganapathy. Amino acid transporter SLC6A14: A novel drug target for colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3585.

Apple consumption is associated with a distinctive microbiota, proteomics and metabolomics profile in the gut of Dawley Sprague rats fed a high-fat diet.

Apples contain bioactive compounds with the potential to alleviate clinical signs associated with obesity, a phenomenon likely related to the composition and function of the gut microbiota. The aim of this study was to investigate the effect of apple supplementation on the fecal microbiota and gut metabolites of Dawley Sprague rats fed a high-fat (HF group) or a low-fat (LF group) diet. The fecal microbiota was examined using 16S marker sequencing targeting the V4 region in a MiSeq instrument (Illumina). With the exception of Blautia, which was higher in supplemented rats compared to controls within the LF group, significant differences in fecal microbiota between supplemented rats and controls were only found in the HF group. This suggests that the effect of apple supplementation on the gut microbiota is strongly dependent on the composition of the diet, a phenomenon with potential consequences for obese human patients. Principal Coordinate Analysis of unweighted UniFrac distances revealed a clear strong separation of bacterial communities based on diet (HF and LF, P = 0.001, R = 0.69, ANOSIM test) and based on apple supplementation within the HF group, albeit less strongly (P = 0.006, R = 0.27, ANOSIM test). No differences were found for fecal SCFAs but proteomics and metabolomics analyses showed differential expression of both proteins and metabolites between supplemented rats and controls in the HF group. The results of this study can guide future explorations of the effect of apple supplementation on human health.

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 Signatures Are Associated with Response to Ustekinumab Therapy among Crohn’s Disease Patients

ABSTRACTThe fecal microbiota is a rich source of biomarkers that have previously been shown to be predictive of numerous disease states. Less well studied is the effect of immunomodulatory therapy on the microbiota and its role in response to therapy. This study explored associations between the fecal microbiota and therapeutic response of Crohn’s disease (CD) patients treated with ustekinumab (UST; Stelara) in the phase 2 CERTIFI study. Using stool samples collected over the course of 22 weeks, the composition of these subjects’ fecal bacterial communities was characterized by sequencing the 16S rRNA gene. Subjects in remission could be distinguished from those with active disease 6 weeks after treatment using random forest models trained on subjects’ baseline microbiota and clinical data (area under the curve [AUC] of 0.844, specificity of 0.831, sensitivity of 0.774). The most predictive operational taxonomic units (OTUs) that were ubiquitous among subjects were affiliated with Faecalibacterium and Escherichia or Shigella. The median baseline community diversity in subjects in remission 6 weeks after treatment was 1.7 times higher than that in treated subjects with active disease (P = 0.020). Their baseline community structures were also significantly different (P = 0.017). Two OTUs affiliated with Faecalibacterium (P = 0.003) and Bacteroides (P = 0.022) were significantly more abundant at baseline in subjects who were in remission 6 weeks after treatment than those with active CD. The microbiota diversity of UST-treated clinical responders increased over the 22 weeks of the study, in contrast to nonresponsive subjects (P = 0.012). The observed baseline differences in fecal microbiota and changes due to therapeutic response support the potential for the microbiota as a response biomarker.

The Impact of NOD2 Variants on Fecal Microbiota in Crohn's Disease and Controls Without Gastrointestinal Disease.

Background/AimsCurrent models of Crohn’s disease (CD) describe an inappropriate immune response to gut microbiota in genetically susceptible individuals. NOD2 variants are strongly associated with development of CD, and NOD2 is part of the innate immune response to bacteria. This study aimed to identify differences in fecal microbiota in CD patients and non-IBD controls stratified by NOD2 genotype.MethodsPatients with CD and non-IBD controls of known NOD2 genotype were identified from patients in previous UK IBD genetics studies and the Cambridge bioresource (genotyped/phenotyped volunteers). Individuals with known CD-associated NOD2 mutations were matched to those with wild-type genotype. We obtained fecal samples from patients in clinical remission with low fecal calprotectin (<250 µg/g) and controls without gastrointestinal disease. After extracting DNA, the V1-2 region of 16S rRNA genes were polymerase chain reaction (PCR)-amplified and sequenced. Analysis was undertaken using the mothur package. Volatile organic compounds (VOC) were also measured.ResultsNinety-one individuals were in the primary analysis (37 CD, 30 bioresource controls, and 24 household controls). Comparing CD with nonIBD controls, there were reductions in bacterial diversity, Ruminococcaceae, Rikenellaceae, and Christensenellaceae and an increase in Enterobacteriaceae. No significant differences could be identified in microbiota by NOD2 genotype, but fecal butanoic acid was higher in Crohn’s patients carrying NOD2 mutations.ConclusionsIn this well-controlled study of NOD2 genotype and fecal microbiota, we identified no significant genotype-microbiota associations. This suggests that the changes associated with NOD2 genotype might only be seen at the mucosal level, or that environmental factors and prior inflammation are the predominant determinant of the observed dysbiosis in gut microbiota.

Comparative analyses of fecal microbiota in Chinese isolated Yao population, minority Zhuang and rural Han by 16sRNA sequencing

The gut microbiome in humans is associated with geography, diet, lifestyles and so on, but its relationship with some isolated populations is not clear. We used the 16sRNA technique to sequence the fecal microbiome in the Chinese isolated Yao population and compared it with the major minority Zhuang and the major ethnic Han populations living in the same rural area. Information about diet frequency and health status and routine serum measurements were collected. The unweighted UniFrac principal coordinates analysis showed significant structural differences in fecal microbiota among the three ethnic groups. Statistically significant differences were observed in the community richness estimator (chaos) and the diversity estimator (Shannon) among the three groups. At the genus level, the fecal samples of the isolated Yao population presented the lowest relative abundance of the Megamonas genus, which was potentially related to the high frequency of bean consumption in the diet. Two enterotypes were identified in the overall fecal microbiota in the three populations. In the isolated Yao population, a higher Bacteroides abundance was observed, but the Prevotella abundance decreased with increased alcohol consumption.

Analysis of gut microbiota diversity and auxiliary diagnosis as a biomarker in patients with schizophrenia: A cross-sectional study

With the advent of sequencing technology, characterization of schizophrenia with underlying probing of gut microbiome can provide abundant clues for diagnosis and prognosis of schizophrenia. In this study, we first compared the difference of gut microbiota between schizophrenia patients and healthy controls by 16S rRNA sequencing. We further explored whether gut microbiota can be used as a biomarker to assist in the diagnosis of schizophrenia. We restricted inclusion criteria strictly to control confounding bias. Finally, we investigated differences in fecal microbiota between 64 schizophrenia patients and 53 healthy controls. At the phylum level, we found that the abundance of Proteobacteria in the schizophrenia patients was significantly increased. At the genus level, the relative abundance of Succinivibrio, Megasphaera, Collinsella, Clostridium, Klebsiella and Methanobrevibacter was significantly higher whereas the abundance of Blautia, Coprococcus, Roseburia was decreased compared to health controls. The receiver operating characteristic curve analysis demonstrated that 12 significant microbiota biomarkers were capable of being used as diagnostic factors for distinguishing the schizophrenia cohort from those in the control cohort (AUC = 0.837). We performed PICRUSt analysis and found that several metabolic pathways differed significantly between healthy controls and schizophrenia patients, including vitamin B6 and fatty acid. In conclusion, there are some difference of gut microbiota between schizophrenia patients and healthy controls and the insights from this study could be used to develop microbiota-based diagnosis for schizophrenia.

Faecal microbiota in dogs with multicentric lymphoma.

Malignant lymphoma B-cell type is the most common canine haematopoietic malignancy. Changes in intestinal microbiota have been implicated in few types of cancer in humans. The aim of this prospective and case-control study was to determine differences in faecal microbiota between healthy control dogs and dogs with multicentric lymphoma. Twelve dogs affected by multicentric, B-cell, stage III-IV lymphoma, and 21 healthy dogs were enrolled in the study. For each dog, faecal samples were analysed by Illumina sequencing of 16S rRNA genes and quantitative PCR (qPCR) for selected bacterial groups. Alpha diversity was significant lower in lymphoma dogs. Principal coordinate analysis plots showed different microbial clustering (P = .001) and linear discriminant analysis effect size revealed 28 differentially abundant bacterial groups in lymphoma and control dogs. The qPCR analysis showed significant lower abundance of Faecalibacterium spp. (q < .001), Fusobacterium spp. (q = .032), and Turicibacter spp. (q = .043) in dogs with lymphoma compared with control dogs. On the contrary, Streptococcus spp. was significantly higher in dogs with lymphoma (q = .041). The dysbiosis index was significantly higher (P < .0001) in dogs with lymphoma. In conclusion, both sequencing and qPCR analyses provided a global overview of faecal microbial communities and showed significant differences in the microbial communities of dogs presenting with multicentric lymphoma compared with healthy control dogs.

Gut Microbiota in Human Adults with Irritable Bowel Syndrome Differs from Healthy Controls

Background Recent evidence suggests that there is a link between irritable bowel syndrome (IBS) and microbiota in the gut. The onset and maintenance of IBS may be caused by gut microbiota, but the causes of the pathophysiology of this disorder are unknown. Method 25 patients who fulfilled Rome III criteria for IBS and 29 age- and gender-matched healthy controls were chosen in this study. The total bacterial DNA isolated from the two populations was investigated through amplicon pyrosequencing of the V3–V4 regions of the 16S ribosomal RNA gene. Results The composition of bacteria in the groups differed between healthy controls and IBS subgroups from phylum to the genus level. Synergistetes phylum (p=0.016), Bacilli class (p=0.006), Lactobacillales order (p=0.006), Enterobacteriales order (p=0.02), the families Streptococcaceae (p=0.009), Enterobacteriaceae (p=0.02), and Enterococcaceae (p=0.001), and the genera Streptococcus (p=0.002), Enterobacter (p=0), Klebsiella (p=0.006), and Enterococcus (p=0.001) exhibited higher levels in IBS patients compared with healthy controls. By contrast, Clostridia class (p=0.024), Betaproteobacteria class (p=0.019), Clostridiales order (p=0.024), the families Bacteroidaceae (p=0.049), Desulfovibrionaceae (p Conclusion There were differences in faecal microbiota between IBS patients and healthy controls. The faecal microbiota of patients with IBS is associated with significant increases in detrimental and decreases in beneficial bacterial groups. Acknowledgment Supported by grants from National Program on Key Basic Research Project (973 Program, 2013CB531405), and the National Natural Science Foundation of China (NSFC, No. 81641029 and 81370113).

Analysis of microbiota in first episode psychosis identifies preliminary associations with symptom severity and treatment response

The effects of gut microbiota on the central nervous system, along its possible role in mental disorders, have received increasing attention. Here we investigated differences in fecal microbiota between 28 patients with first-episode psychosis (FEP) and 16 healthy matched controls and explored whether such differences were associated with response after up to 12months of treatment. Numbers of Lactobacillus group bacteria were elevated in FEP-patients and significantly correlated with severity along different symptom domains. A subgroup of FEP patients with the strongest microbiota differences also showed poorer response after up to 12months of treatment. The present findings support the involvement of microbiota alterations in psychotic illness and may provide the basis for exploring the benefit of their modulation on treatment response and remission.

Structure and Function of the Fecal Microbiota in Diarrheic Neonatal Piglets.

Diarrhea is a leading cause of increased mortality in neonatal and young piglets. Aberration of the gut microbiota is one important factor in the etiology of piglet diarrhea. However, information regarding the structure and function of the gut microbiome in diarrheic neonatal piglets is limited. To investigate the composition and functional potential of the fecal microbiota in neonatal piglets, we performed 16S rRNA gene sequencing on 20 fecal samples from diarrheic piglets and healthy controls, and metagenomics sequencing on a subset of six samples. We found striking compositional and functional differences in fecal microbiota between diarrheic and healthy piglets. Neonatal piglet diarrhea was associated with increases in the relative abundance of Prevotella, Sutterella, and Campylobacter, as well as Fusobacteriaceae. The increased relative abundance of Prevotella was correlated with the reduction in Escherichia coli and the majority of beneficial bacteria that belonging to the Firmicutes phylum (e.g., Enterococcus, Streptococcus, Lactobacillus, Clostridium, and Blautia) in diarrheic piglets. The differentially functional gene abundances in diarrheic piglets were an increase in bacterial ribosome, and contributed primarily by the genera Prevotella, this indicates a growth advantage of the Prevotella in diarrheic conditions. Additional functional gene sets were associated with the reduction of polyamine transport, monosaccharide and sugar-specific PTS transport, amino acid transport, and two-component regulatory system. These profiles likely impact the ability to transport and uptake nutrients, as well as the ability to fight microbial infections in the piglet gut ecosystem. This work identifies a potential role for Prevotella in the community-wide microbial aberration and dysfunction that underpins the pathogenesis of piglet diarrhea. Identification of these microbial and functional signatures may provide biomarkers of neonatal piglet diarrhea.

Temporal Stability and the Effect of Transgenerational Transfer on Fecal Microbiota Structure in a Long Distance Migratory Bird.

Animal bodies are inhabited by a taxonomically and functionally diverse community of symbiotic and commensal microorganisms. From an ecological and evolutionary perspective, inter-individual variation in host-associated microbiota contributes to physiological and immune system variation. As such, host-associated microbiota may be considered an integral part of the host’s phenotype, serving as a substrate for natural selection. This assumes that host-associated microbiota exhibits high temporal stability, however, and that its composition is shaped by trans-generational transfer or heritable host-associated microbiota modulators encoded by the host genome. Although this concept is widely accepted, its crucial assumptions have rarely been tested in wild vertebrate populations. We performed 16S rRNA metabarcoding on an extensive set of fecal microbiota (FM) samples from an insectivorous, long-distance migratory bird, the barn swallow (Hirundo rustica). Our data revealed clear differences in FM among juveniles and adults as regards taxonomic and functional composition, diversity and co-occurrence network complexity. Multiple FM samples from the same juvenile or adult collected within single breeding seasons exhibited higher similarity than expected by chance, as did adult FM samples over two consecutive years. Despite low effect sizes for FM stability over time at the community level, we identified an adult FM subset with relative abundances exhibiting significant temporal consistency, possibly inducing long-term effects on the host phenotype. Our data also indicate a slight maternal (but not paternal) effect on FM composition in social offspring, though this is unlikely to persist into adulthood. We discuss our findings in the context of both evolution and ecology of microbiota vs. host interactions and barn swallow biology.

English

Gut microbiota is mainly composed of four phyla; however, the human gut microbiota is dominated by only 2 of them and most of them are uncultivable. Psoriasis is an inflammatory skin disorder with associated inflammation of internal organs and musculoskeletal system. This study aimed to, identify numerically abundant bacteria phyla in fecal samples of patients with psoriasis, evaluate whether differences in fecal microbiota correlate with the occurrence of psoriasis and understand the possible pathogenesis behind psoriasis-related bacterial targets. From April, 2015 to 2016, 90 adults were selected prospectively to allocate 2 equal groups: Gr1 (45 cases) patients with psoriasis, and Gr2 (45 cases) healthy controls. Psoriasis Area and Severity Index (PASI) for each psoriasis patient was detected. All subjects were subjected to history taking, clinical examination, and fecal real time polymerase chain reaction (PCR) testing for the Firmicutes, Bacteroidetes, and Actinobacterial phyla. In both groups, Firmicutes were the most common detected phylum followed by Bacteroidetes and finally Actinobacterial phyla. High statistically significant difference was reported for the Firmicutes/ Bacteroidetes ratio between the psoriasis patients and the control group and showed statistically significant positive correlations with PASI. Actinobacterial count was significantly higher in the control group than in psoriasis patients and showed statistically significant negative correlations with PASI. It is believed that, there are fractions of the gut microbiota with the ability to counteract inflammation (Bacteroidetes and Actinobacterial), and others that are more prone to induce inflammation (Firmicutes) and the disturbed microbiome ratio may be the cause for inducing psoriasis. &nbsp; Key words: Psoriasis, gut microbiota, real time polymerase chain reaction (PCR), firmicutes, bacteroidetes, actinobacteria.

Altered Fecal Microbiota Correlates with Liver Biochemistry in Nonobese Patients with Non-alcoholic Fatty Liver Disease.

Increasing evidence suggests a role of intestinal dysbiosis in obesity and non-alcoholic fatty liver disease (NAFLD). But it remains unknown in nonobese NAFLD. This prospective, cross-sectional study sought to characterize differences in fecal microbiota between nonobese adult individuals with and without NAFLD and their potential association with metabolic markers of disease progression. A total of 126 nonobese subjects were enrolled: 43 NAFLD and 83 healthy controls (HC). The microbial community was profiled by denaturing gradient gel electrophoresis and examined by 454 pyrosequencing of the 16S ribosomal RNA V3 region. Lower diversity and a phylum-level change in the fecal microbiome were found in NAFLD. Compared with HC, patients had 20% more phylum Bacteroidetes (p = 0.005) and 24% less Firmicutes (p = 0.002). Within Firmicutes, four families and their 8 genera, which were short-chain fatty acids-producing and 7α-dehydroxylating bacteria, were significantly decreased. Moreover, Gram-negative (G−) bacteria were prevalent in NAFLD (p = 0.008). Furthermore, a significant correlation with metabolic markers was revealed for disturbed microbiota in NAFLD. This novel study indicated that intestinal dysbiosis was associated with nonobese NAFLD and might increase the risk of NAFLD progression.

Significant differences in fecal microbiota are associated with various stages of glucose tolerance in African American male veterans

The importance of gut microbiota in pathogenesis of diabetes remains unknown. This study investigated the relationship between microbiota and metabolic markers in African American men (AAM) with prediabetes and hypovitaminosis D. The study was ancillary to a randomized trial of vitamin D supplementation with weekly ergocalciferol (50,000 IU) conducted in AAM veterans over 12 months (D Intervention in Veterans Affairs). Glycemic groups (Gr) were characterized based on changes in oral glucose tolerance between baseline and exit. Subjects with stable normal glucose tolerance were assigned to Gr-1 and those with stable prediabetes (impaired glucose tolerance and impaired fasting glucose) to Gr-2. Microbiota composition was analyzed in stool collected at the exit (n = 115) and compared between Gr-1 and Gr-2, as well as between the lowest and highest quartiles of dietary intake of energy and fat, hemoglobin A1c, and serum 25-hydroxyvitamin D (25[OH]D) level. Differences between Gr-1 and Gr-2 included the Bacteroidetes/Firmicutes and Bacteroidales/Clostridia ratios and differences in genera such as Ruminococcus and Dialister. Changes in specific taxa associated with the lowest and highest quartiles of 25(OH)D (eg, Ruminococcus, Roseburia, Blautia, Dorea) were clearly distinct from those of dietary intake (eg, Bacteroides, Bacteroides/Prevotella ratio) or A1c (eg, Faecalibacterium, Catenibacterium, Streptococcus). These findings suggest a novel interaction between microbiota and vitamin D and a role for microbiota in early stages of diabetes development. Although results suggest that specific taxa are associated with glycemic stability over time, a causative relationship between microbiota makeup and dysglycemia is still to be demonstrated.

Analysis of swine fecalmicrobiota at various growth stages.

Recent obesity studies in humans and rodents have suggested that host weight gain is significantly associated with energy harvesting efficiency which is regulated by gut microbiota. Antibiotic growth promoters have been banned as feed additives in many countries. In this study, we aimed to provide knowledge of swine fecal microbiota by analyzing bacterial 16S rRNA gene sequences. Our results showed that swine fecal bacterial composition varied at each growth stage. Bacteroidetes decreased as the swine gained weight and unclassified genera significantly increased at later growth stages. Operational taxonomic unit (OTU) distribution analysis showed that the bacterial community difference was most significant between growers and finishers, while analysis of shared OTUs indicated a greater proportion of common species between growers and finishers. The differential abundance test between growers and finishers detected that nearly half of the species were shared OTUs, suggesting that differential abundance of each bacterial species predominantly controls bacterial community differences. Although functions of these bacteria are yet to be identified, understanding differences in fecal microbiota between each growth stage will provide additional insights for further studies related to swine gut microbiota.

Low serum enterolactone concentration is associated with low colonicLactobacillus–Enterococcuscounts in men but is not affected by a synbiotic mixture in a randomised, placebo-controlled, double-blind, cross-over intervention study

The aims of the present study were to assess the possible differences in faecal microbiota between men with a low serum enterolactone concentration and those with a high concentration, and to investigate the impact of a synbiotic mixture on serum enterolactone concentration in men with a low concentration. We compared faecal microbiota between ten men with the lowest serum enterolactone concentration and ten men with the highest concentration at recruitment (n 84). Furthermore, we carried out a randomised, double-blind, placebo-controlled, cross-over intervention study (6-week intervention periods and 4-week washout period) to investigate the impact of a synbiotic mixture (two Lactobacillus strains, one Bifidobacterium strain, one Propionibacterium strain and galacto-oligosaccharides (32g/l)) on serum enterolactone concentration in fifty-two men who had a concentration <20nmol/l. Serum sensitive C-reactive protein (CRP) concentration was measured at the end of the first intervention period. Men with a low serum enterolactone concentration when compared with those with a high concentration had less faecal bacteria, especially those belonging to the Lactobacillus-Enterococcus group (median 8·2 (interquartile range 7·8-8·4)log10 colony-forming units/g v. median 8·8 (interquartile range 8·5-8·9)log10 colony-forming units/g, P=0·009). The synbiotic mixture that was used did not have a significant effect on serum enterolactone (synbiotic v. placebo ratio 0·96 (95% CI 0·76, 1·22), P=0·724) or serum sensitive CRP (synbiotic v. placebo ratio 0·99 (95% CI 0·74, 1·33), P=0·954) concentration. Men with a low serum enterolactone concentration harbour less colonic bacteria, especially those belonging to the Lactobacillus-Enterococcus group. A synbiotic mixture does not increase serum enterolactone concentration.

Differences in Fecal Microbiota in Different European Study Populations in Relation to Age, Gender, and Country: a Cross-Sectional Study

A cross-sectional study on intestinal microbiota composition was performed on 230 healthy subjects at four European locations in France, Germany, Italy, and Sweden. The study participants were assigned to two age groups: 20 to 50 years (mean age, 35 years; n = 85) and >60 years (mean age, 75 years; n = 145). A set of 14 group- and species-specific 16S rRNA-targeted oligonucleotide probes was applied to the analysis of fecal samples by fluorescence in situ hybridization coupled with flow cytometry. Marked country-age interactions were observed for the German and Italian study groups. These interactions were inverse for the predominant bacterial groups Eubacterium rectale-Clostridium coccoides and Bacteroides-Prevotella. Differences between European populations were observed for the Bifidobacterium group only. Proportions of bifidobacteria were two- to threefold higher in the Italian study population than in any other study group, and this effect was independent of age. Higher proportions of enterobacteria were found in all elderly volunteers independent of the location. Gender effects were observed for the Bacteroides-Prevotella group, with higher levels in males than in females. In summary, age-related differences in the microbiota makeup were detected but differed between the study populations from the four countries, each showing a characteristic colonization pattern.