Human microbiome digest, September 29, 2014


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“


Human microbiome, August 26, 2014

Gut microbiome structure in the first years of life, lung microbiome in pneumonia and tuberculosis, why iron supplements might not always be a good thing, and the Microbiome Diet Book.

Pregnancy and birth

The Intestinal Microbiome in Early Life: Health and Disease – Marie-Claire Arrieta – Frontiers in Immunology

“This review describes the gut microbiome structure and function during the formative first years of life, as well as the environmental factors that determine its composition.”

Oral microbiome

Review: The oral microbiome diversity and its relation to human diseases – Jinzhi He – Folia Microbiologica

“In this review, we focus on the recent progress in this field, including the oral microbiome composition and its association with human diseases.”

Respiratory microbiome

Single-Molecule Long Read 16S Sequencing to Characterize the Lung Microbiome from Mechanically Ventilated Patients with Suspected Pneumonia – Ian Toma – Journal of Clinical Microbiology

“The present study used NGS of essentially full-length PCR-amplified 16S ribosomal DNA from the bronchial aspirates of intubated patients with suspected pneumonia.”

Respiratory tract clinical sample selection for microbiota analysis in patients with pulmonary tuberculosis – Luz Elena Botero – Microbiome Journal

“Most V1-V2 16S rRNA gene sequences belonged to the phyla Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, and Fusobacteria, with differences in relative abundances and in specific taxa associated with each sample type. “

Gut microbiome

* Iron fortification adversely affects the gut microbiome, increases pathogen abundance and induces intestinal inflammation in Kenyan infants – Tanja Jaeggi – Gut

“Using pyrosequencing, +FeMNPs increased enterobacteria, particularly Escherichia/Shigella (p=0.048), the enterobacteria/bifidobacteria ratio (p=0.020), and Clostridium (p=0.030).”

Animal models of microbiome research

Amelioration of DSS-induced murine colitis by VSL#3 supplementation is primarily associated with changes in ileal microbiota composition – Jordan S. Mar – Gut Microbes

“Microbiota profiling revealed distinct bacterial community compositions in the ileum, cecum and colon of control untreated animals”

Commensal Bacteria Regulate Thymic Aire Expression – Akihito Nakajima – PLOS ONE

“autoimmune regulator (Aire) expression in thymic epithelial cells (TECs), main components of the thymic microenvironment, was decreased in comparison to specific pathogen-free (SPF) mice and Nod1 wild-type (WT) mice, respectively. “

Microbiome in the News

Overselling the Microbiome Award: The Microbiome Diet Book – Jonathan Eisen – The Tree of Life

“Sound too good to be true? Well, that is because it is.”


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 –

“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?”