Project description:In a prior report, we observed two distinct lung microbiomes in healthy subjects that we termed â??pneumotypesâ??: pneumotypeSPT, characterized by high bacterial load and supraglottic predominant taxa (SPT) such as the anaerobes Prevotella and Veillonella; and pneumotypeBPT, with low bacterial burden and background predominant taxa (BPT) found in the saline lavage and bronchoscope. Here, we determined the prevalence of these two contrasting lung microbiome types, in a multi-center study of healthy subjects. We confirmed that a lower airway microbiome enriched with upper airway microbes (pneumotypeSPT) was present in ~45% of healthy individuals. Cross-sectional Multicenter cohort. BAL of 49 healthy subjects from three cohort had their lower airway microbiome assessed by 16S rDNA sequencing and microbial gene content (metagenome) was computationally inferred from taxonomic assignments. The amplicons from total 100 samples are barcoded; the barcode and other clinical characteristics (e.g. inflammatory biomarkers and metabolome data) for each sample are provided in the 'Pneumotype.sep.Map.A1.txt' file.
Project description:Complex oligosaccharides found in human milk play a vital role in gut microbiome development for the human infant. Bovine milk oligosaccharides (BMO) have similar structures with those derived from human milk, but have not been well studied for their effects on the healthy adult human gut microbiome. Healthy human subjects consumed BMO over two-week periods at two different doses and provided fecal samples. Metatranscriptomics of fecal samples was conducted to determine microbial and host gene expression in response to the supplement. Fecal samples were also analyzed by mass spectrometry to determine levels of undigested BMO. No changes were observed in microbiome activity across all participants. Repeated sampling enabled subject-specific analyses: four of six participants had minor, yet statistically significant, changes in microbial activity. No significant change was observed in the gene expression of host cells in stool. Levels of BMO excreted in feces after supplementation were not significantly different from placebo and were not correlated with dosage or expressed microbial enzyme levels. Collectively, these data suggest that BMO is fully digested in the human gastrointestinal tract prior to stool collection. Participants’ gut microbiomes remained stable but varied between individuals. Additionally, the unaltered host transcriptome provides further evidence for the safety of BMO as a dietary supplement or food ingredient.