Human microbiome digest, September 29, 2014

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Smoking and the subgingival ecosystem, inflammatory bowel diseases, iron in the gut, and metabolism of acetaminophen.

Pregnancy and birth

External influence of early childhood establishment of gut microbiota and subsequent health implications – Peris M. Munyaka – Frontiers in Pediatrics

“Early exposures impacting the intestinal microbiota are associated with the development of childhood diseases that may persist to adulthood”

Human oral microbiome

* Smoking decreases structural and functional resilience in the subgingival ecosystem – Vinayak Joshi – Journal of Clinical Periodontology

“16S cloning and sequencing was used for bacterial identification and multiplexed bead-based flow cytometry was used to quantify the levels of 27 immune mediators.”

Human gut microbiome

Functional Impacts of the Intestinal Microbiome in the Pathogenesis of Inflammatory Bowel Disease – Jennifer Li – Inflammatory Bowel Diseases

“We highlight functional roles of specific bacterial groups in the development and management of IBD. “

Nutritional iron turned inside out: intestinal stress from a gut microbial perspective – Guus A.M. Kortman – FEMS Microbiology Reviews

“This review covers the multifaceted aspects of nutritional iron stress with respect to growth, composition, metabolism and pathogenicity of the gut microbiota in relation to human health.”

Animal models of microbiome research

The role of intestinal microbiota in murine models of acetaminophen-induced hepatotoxicity – Lucia A Possamai – Liver International

“A urinary metabolic profile was obtained using 1H-NMR. Baseline hepatic glutathione content and CYP2E1 expression were quantified.”

Dietary Xylo-oligosaccharide stimulates intestinal bifidobacteria and lactobacilli but has limited effect on intestinal integrity in rats – Ellen Gerd Christensen – BMC Research Notes

“Changes in faecal and caecal bacterial composition determined by 16S rRNA gene sequencing and quantitative PCR for selected bacterial groups revealed that the overall bacterial composition did not differ markedly“

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Human microbiome digest, September 16, 2014

Still catching up after my vacation, but almost there!

Some general microbiome reviews, using saliva to track human evolution, probiotics that actually change the microbiome, and several animal model studies.

 

General microbiome reviews

Which is more important for classifying microbial communities: who’s there or what they can do? – Zhenjiang Xu – ISME Journal

“… might we not instead expect that function would be substantially more important for classifying biologically meaningful groups of samples than who is providing those functions? “

Microbiome analysis – from technical advances to biological relevance – Michelle I. Smith – F1000Prime Reports

“Here, we introduce techniques that go beyond identifying the taxa present within a sample and examine the biological function of the microbiome or the host-microbiome interaction.”

From barcoding single individuals to metabarcoding biological communities: towards an integrative approach to the study of global biodiversity – Melania E. Cristescu – Trends in Ecology & Evolution

“DNA-based species identification, known as barcoding, transformed the traditional approach to the study of biodiversity science. “

Human oral microbiome

Global analysis of saliva as a source of bacterial genes for insights into human population structure and migration studies – Karsten Henne – BMC Evolutionary Biology

“By focussing on the house-keeping gene gdh .., on the virulence gene gtf .. of mitis-streptococci and on the 16S-23S rRNA internal transcribed spacer (ITS) region of the Fusobacterium nucleatum/periodonticum-group we here tested the hypothesis that bacterial genes from human saliva have the potential for distinguishing human populations.’

Microbial community in persistent apical periodontitis: a 16S rRNA gene clone library analysis – M. N. Zakaria – International Endodontic Journal

“Whilst a diverse bacterial species were observed in the persistent apical lesions, some characteristic patterns of bacterial community were found in the symptomatic lesions. “

The Adenoid Microbiome in Recurrent Acute Otitis Media and Obstructive Sleep Apnea – Carolyn P. Ojano-Dirain – Otolaryngology – Head and Neck Surgery

“Microbes are present on all adenoid specimens, however, the microbial profile differs between recurrent AOM and OSA.”

Human gut microbiome

Susceptibility to Campylobacter Infection Is Associated with the Species Composition of the Human Fecal Microbiota – Johan Dicksved – mBio

“Here we address this by prospectively studying the gut microbiota composition before, during, and after natural Campylobacter infection in exposed poultry abattoir workers.”

Eukaryote Culturomics of the Gut Reveals New Species – Nina Gouba, Didier Raoult, Michel Drancourt – PLOS ONE

“We further explored this repertoire using PCR-sequencing and culture in seven individuals living in four tropical countries. A total of 41 microeukaryotes including 38 different fungal species and three protists were detected. “

Review: Decade in review—gut microbiota: The gut microbiota era marches on – Francisco Guarner – Nature Reviews Gastroenterology & Hepatology

“Research on the gut microbial communities harboured in the human gut is progressing rapidly owing to the availability of novel and reliable tools for analysis.”

Modulation of Fecal Clostridiales Bacteria and Butyrate by Probiotic Intervention with Lactobacillus paracasei DG Varies among Healthy Adults – Chiara Ferrario – Journal of Nutrition

“High-throughput 16S ribosomal RNA gene sequencing was used to characterize the fecal microbiota in healthy adults (23–55 y old) of both sexes, before and after 4 wk of daily consumption of a capsule containing at least 24 billion viable Lactobacillus paracasei DG cells”

Review: The gut microbiota, bacterial metabolites and colorectal cancer – Petra Louis, Georgina L. Hold & Harry J. Flint – Nature Reviews Microbiology

“In this Review, we discuss the relationship between diet, microbial metabolism and CRC and argue that the cumulative effects of microbial metabolites should be considered in order to better predict and prevent cancer progression.”

Changes of the human gut microbiome induced by a fermented milk product – Patrick Veiga – Nature Scientific Reports

“Our data challenge the view that microbes ingested with food have little impact on the human GM functioning and rather provide support for beneficial health effects.”

Gut Microbiome and Multiple Sclerosis – Pavan Bhargava, Ellen M. Mowry – Current Neurology and Neuroscience Reports

“We examine the different sources of information linking the gut microbiota to multiple sclerosis and examine the future avenues for utilizing the knowledge of the gut microbiome to potentially treat and prevent multiple sclerosis.”

Microbial Modulation of Insulin Sensitivity – Muhammad Tanweer Khan, Max Nieuwdorp, Fredrik Bäckhed – Cell Metabolism

“The gut microbiota has emerged as an integral factor that impacts host metabolism and has been suggested to play a vital role in metabolic diseases such as obesity, insulin resistance, type 2 diabetes, and cardiovascular disease.”

Gut Microbial Community Structure and Complications After Kidney Transplantation: A Pilot Study – Lee, John R – Transplantation

“We characterized bacterial composition by polymerase chain reaction amplification of the 16S rRNA V4-V5 variable region and deep sequencing using the Illumina MiSeq platform.’

Human genital microbiome

Association between cigarette smoking and the vaginal microbiota: a pilot study – Rebecca M Brotman – BMC Infectious Diseases

“Smokers had a lower proportion of vaginal Lactobacillus spp. compared to non-smokers.”

Pregnancy and birth

Human Breast Milk – The Magic In The Microbiome – Science20

“Ma et al (2014 submitted manuscript) recently postulated that the opportunistic pathogen such as Staphylococcus aureus, which has been confirmed to exist in the human milk microbiome, is normally suppressed by a network of beneficial bacteria coexisted in the breast milk microbiome, but may become source of infectious mastitis when the host environment permits.”

Animal models of human microbiome research

Antibiotic Treatment of Pregnant Non-Obese Diabetic Mice Leads to Altered Gut Microbiota and Intestinal Immunological Changes in the Offspring – N. Tormo-Badia – Scandinavian Journal of Immunology

“we found a differential clustering of gut microbiota in the offspring from NOD mothers treated with antibiotics during gestation compared with offspring from control mothers.”

Shifts in microbiota species and fermentation products in a dietary model enriched in fat and sucrose – U. Etxeberria – Beneficial Microbes

“The aim of the present study was to identify gut microbiota dysbiosis and associated metabolic changes produced in male Wistar rats fed a HFS diet for 6 weeks and compare it with the basal microbial composition.”

The short chain fatty acids, butyrate and propionate, have differential effects on the motility of the guinea pig colon – Norm R. Hurst – Neurogastroenterology & Motility

“We hypothesized that the effect of SCFAs on colonic motility varies with chain length and aimed to determine the effects of SCFAs on propagating and non-propagating contractions of guinea pig proximal and distal colon.”

Small Bowel Resection Induces Long-Term Changes in the Enteric Microbiota of Mice – J. Sommovilla – Journal of Gastrointestinal Surgery

Bowel resection induces long-term changes in the microbial community of the murine ileum, but not at more distal sites of the gastrointestinal tract. “

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Microbiome digest, July 30

Host diet, sex, and the microbiome, smoking cessation, eukaryotic microbes, CRISPRs and my picks.

Gut microbiome

Individual diet has sex-dependent effects on vertebrate gut microbiota – Daniel I. Bolnick – Nature Communications

“Here we show that gut microbiota composition depends on interactions between host diet and sex within populations of wild and laboratory fish, laboratory mice and humans. “

Smoking Cessation Alters Intestinal Microbiota: Insights from Quantitative Investigations on Human Fecal Samples Using FISH – Biedermann L – Inflammatory Bowel Diseases

“As determined by fluorescence in situ hybridization, an independent direct quantitative microbial approach, we could confirm that intestinal microbiota composition in humans is influenced by smoking.”

More microbiology

Diversity of diversity: conceptual and methodological differences in biodiversity estimates of eukaryotic microbes as compared to bacteria – Jean-David Grattepanche – Trends in Microbiology

“High-throughput sequencing tools underestimate the diversity of eukaryotes by removing morphospecies.”

Microbes in the news

A Trip Overseas Could Change The Bugs Living In Your Gut – Bahar Gholipour – Huntington Post

“I was amazed to see how profoundly a single food poisoning event impacted the gut bacteria,” David, who was a researcher at Harvard University at the time of the study, said in a statement.

Researcher Using Next-Generation Sequencing, Other New Methods to Rapidly Identify Pathogens – Joe Montgomery – Kansas State University News Office – Labmanager.com

“Benjamin Hause, an assistant research professor at the Kansas State Veterinary Diagnostic Laboratory at Kansas State University, recently published an article about one of his discoveries, porcine enterovirus G, which is an important find in the United States.”

Antibiotics and resistance

Perturbation of Iron Homeostasis Promotes the Evolution of Antibiotic Resistance – Orsolya Méhi – Molecular Biology and Evolution

“To decipher the underlying molecular mechanisms, we first performed a global transcriptome analysis and demonstrated that the set of genes regulated by Fur change substantially in response to antibiotic treatment. “

Phages, viruses, and CRISPRs

Adaptation in bacterial CRISPR-Cas immunity can be driven by defective phages – Alexander P. Hynes – Nature Communications

“Here we demonstrate that cells can acquire spacers from defective phages at a rate directly proportional to the quantity of replication-deficient phages to which the cells are exposed.”

Dr. Bik’s Picks

Contamination hits cell work: Mycoplasma infestations are widespread and costing laboratories millions of dollars in lost research – Ewen Callaway – Nature

“A total of 11% of the samples were found to contain Mycoplasma DNA at levels indicative of contamination.”

Five daily portions of fruit and vegetables may be enough to lower risk of early death – Science Daily

“Eating five daily portions of fruit and vegetables is associated with a lower risk of death from any cause, particularly from cardiovascular disease, but beyond five portions appears to have no further effect, finds a new study.”

Lands’ End Announces Science-Themed Tees For Girls After Mom’s Letter Goes Viral – Jessica Samakow – The Huffington Post

My daughter was very confused. Lots of her friends that are girls love science, too. Why were there no cool science shirts for girls?”

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