Project description:Broad-spectrum antibiotics are frequently prescribed to children. The period of early-childhood represents a time where the developing microbiota may be more sensitive to environmental perturbations, which thus might have long-lasting host consequences. We hypothesized that even a single early-life broad-spectrum antibiotic course at a therapeutic dose (PAT) leads to durable alterations in both the gut microbiota and host immunity. In C57BL/6 mice, a single early-life tylosin (macrolide) course markedly altered the intestinal microbiome, and affected specific intestinal T-cell populations and secretory IgA expression, but PAT-exposed adult dams had minimal immunologic alterations. No immunological effects were detected in PAT-exposed germ-free animals; indicating that microbiota are required for the observed activities. Together these results indicate the impact of a single therapeutic early-life antibiotic course altering the microbiota and modulating host immune phenotypes that persist long after exposure has ceased.
Project description:The mammalian gastrointestinal tract contains a diverse ecosystem of microbial species collectively making up the gut microbiome. Emerging evidence highlights a critical relationship between gut microbiota and neurocognitive development. Consumption of unhealthy yet palatable dietary factors associated with obesity and metabolic dysfunction (e.g., saturated fat, added sugar) produces microbiota dysbiosis and negatively impacts neurocognitive function, particularly when consumed during early life developmental periods. Here we explore whether excessive early life consumption of added sugars negatively impacts neurocognitive development via the gut microbiome. Using a rodent model of habitual sugar-sweetened beverage (SSB) consumption during the adolescent stage of development, we first show that excessive early life sugar intake impairs hippocampal-dependent memory function when tested during adulthood while preserving other neurocognitive domains. Gut microbiome genomic sequencing analyses reveal that early life SSB consumption alters the abundance of various bacterial populations, including elevations in operational taxonomic units within the genus Parabacteroides (P. distasonis and P. johnsonii) whose abundance negatively correlated with memory task performance. Additional results reveal that in vivo Parabacteroides enrichment of cultured P. distasonis and P. johnsonii bacterial species in adolescent rats severely impairs memory function during adulthood. Hippocampus transcriptome analyses identify gene expression alterations in neurotransmitter synaptic signaling, intracellular kinase signaling, metabolic function, neurodegenerative disease, and dopaminergic synaptic signaling-associated pathways as potential mechanisms linking microbiome outcomes with memory impairment. Collectively these results identify microbiota dysbiosis as a mechanism through which early life unhealthy dietary patterns negatively impact neurocognitive outcomes.
Project description:Background: Exposure to persistent organic pollutants (POPs) and disruptions in the gastrointestinal microbiota have been positively correlated with a predisposition to factors such as obesity, metabolic syndrome, and type 2 diabetes; however, it is unclear how the microbiome contributes to this relationship.
Objective: This study aimed to explore the association between early-life exposure to a potent aryl hydrocarbon receptor (AHR) agonist and persistent disruptions in the microbiota, leading to impaired metabolic homeostasis later in life.
Methods: This study utilized metagenomics, NMR- and mass spectrometry-based metabolomics, and biochemical assays to analyze the gut microbiome composition and function, as well as the physiological and metabolic effects of early-life exposure to 2,3,7,8-tetrachlorodibenzofuran (TCDF) in conventional, germ-free (GF), and Ahr-null mice. The impact of TCDF on Akkermansia muciniphila (A. muciniphila) in vitro was assessed using optical density (OD 600), flow cytometry, transcriptomics, and mass spectrometry-based metabolomics.
Results: TCDF-exposed mice exhibited disruption in the gut microbiome community structure and function, characterized by lower abundances of A. muciniphila, lower levels of cecal short chain fatty acids (SCFAs) and indole-3-lactic acid (ILA), and a reduction in gut hormones GLP-1 and PYY. Importantly, microbial and metabolic phenotypes associated with early-life POP exposure were transferable to GF recipients in the absence of POP carry-over. In addition, AHR-independent interactions between POPs and the microbiota were observed, significantly affected the growth, physiology, gene expression, and metabolic activity of A. muciniphila, resulting in suppressed activity along the ILA pathway.
Conclusions: These data point to the complex effects of POPs on the host and microbiota, providing strong evidence that early-life, short-term, and self-limiting POP exposure can adversely impact the microbiome, persisting into later life with associated health implications.
Project description:Nutrition has a vital role in shaping the intestinal microbiome. The impact of nutrients and the consequences of enteral deprivation on the small intestinal mucosal microbiota, specifically in early life, has not been well described. Our aim was to study the impact of enteral deprivation on the small intestine mucosal microbiome and to search for factors that shape this interaction in early life. Host seem to be the most dominant factor in the structure of the early life mucosal microbial small intestine community. Under conditions of nutrient deprivation, there are specific changes in host proteomics. Further research is needed to better define and understand this host-microbe-nutrition interaction in the small intestine.
Project description:On going efforts are directed at understanding the mutualism between the gut microbiota and the host in breast-fed versus formula-fed infants. Due to the lack of tissue biopsies, no investigators have performed a global transcriptional (gene expression) analysis of the developing human intestine in healthy infants. As a result, the crosstalk between the microbiome and the host transcriptome in the developing mucosal-commensal environment has not been determined. In this study, we examined the host intestinal mRNA gene expression and microbial DNA profiles in full term 3 month-old infants exclusively formula fed (FF) (n=6) or breast fed (BF) (n=6) from birth to 3 months. Host mRNA microarray measurements were performed using isolated intact sloughed epithelial cells in stool samples collected at 3 months. Microbial composition from the same stool samples was assessed by metagenomic pyrosequencing. Both the host mRNA expression and bacterial microbiome phylogenetic profiles provided strong feature sets that clearly classified the two groups of babies (FF and BF). To determine the relationship between host epithelial cell gene expression and the bacterial colony profiles, the host transcriptome and functionally profiled microbiome data were analyzed in a multivariate manner. From a functional perspective, analysis of the gut microbiota's metagenome revealed that characteristics associated with virulence differed between the FF and BF babies. Using canonical correlation analysis, evidence of multivariate structure relating eleven host immunity / mucosal defense-related genes and microbiome virulence characteristics was observed. These results, for the first time, provide insight into the integrated responses of the host and microbiome to dietary substrates in the early neonatal period. Our data suggest that systems biology and computational modeling approaches that integrate “-omic” information from the host and the microbiome can identify important mechanistic pathways of intestinal development affecting the gut microbiome in the first few months of life. KEYWORDS: infant, breast-feeding, infant formula, exfoliated cells, transcriptome, metagenome, multivariate analysis, canonical correlation analysis 12 samples, 2 groups
Project description:The study investigated the impact of environment on the composition of the gut microbiota and mucosal immune development and function at gut surfaces in early and adult life. Piglets of similar genotype were reared in indoor and outdoor environments and in an experimental isolator facility. Mucosa-adherent microbial diversity in the pig ileum was characterized by sequence analysis of 16S rRNA gene libraries. Host-specific gene responses in gut ileal tissues to differences in microbial composition were investigated using Affymetrix microarray technology and Real-time PCR.
Project description:The early life microbiome plays important roles in host immunological and metabolic development. Because type 1 diabetes (T1D) incidence has been increasing substantially in recent decades, we hypothesized that early-life antibiotic use alters gut microbiota that predisposes to disease. Using NOD mice that are genetically susceptible to T1D, we examined the effects of exposure to either continuous low-dose antibiotics or pulsed therapeutic antibiotics (PAT) early in life, mimicking childhood exposures. We found that in mice receiving PAT, T1D incidence was significantly higher, microbial community composition and structure differed compared with controls. In pre-diabetic male PAT mice, the intestinal lamina propria had lower Th17 and T reg proportions and intestinal SAA expression than in controls, suggesting key roles in transducing the altered microbiota signals. PAT affected microbial lipid metabolism and host cholesterol biosynthetic gene expression. These findings show that early-life antibiotic treatments alter the gut microbiota and its metabolic capacities, intestinal gene expression, and T-cell populations, accelerating T1D onset in NOD mice.
Project description:Broad-spectrum antibiotics are frequently prescribed to children. The period of early-childhood represents a time where the developing microbiota may be more sensitive to environmental perturbations, which thus might have long-lasting host consequences. We hypothesized that even a single early-life broad-spectrum antibiotic course at a therapeutic dose (PAT) leads to durable alterations in both the gut microbiota and host immunity. In C57BL/6 mice, a single early-life tylosin (macrolide) course markedly altered the intestinal microbiome, and affected specific intestinal T-cell populations and secretory IgA expression, but PAT-exposed adult dams had minimal immunologic alterations. No immunological effects were detected in PAT-exposed germ-free animals; indicating that microbiota are required for the observed activities. Transfer of PAT-perturbed microbiota led to delayed sIgA expression indicating that the altered microbiota is sufficient to transfer PAT-induced effects. PAT exposure had lasting and transferable effects on microbial community network structure. Together these results indicate the impact of a single therapeutic early-life antibiotic course altering the microbiota and modulating host immune phenotypes that persist long after exposure has ceased.
Project description:Broad-spectrum antibiotics are frequently prescribed to children. The period of early-childhood represents a time where the developing microbiota may be more sensitive to environmental perturbations, which thus might have long-lasting host consequences. We hypothesized that even a single early-life broad-spectrum antibiotic course at a therapeutic dose (PAT) leads to durable alterations in both the gut microbiota and host immunity. In C57BL/6 mice, a single early-life tylosin (macrolide) course markedly altered the intestinal microbiome, and affected specific intestinal T-cell populations and secretory IgA expression, but PAT-exposed adult dams had minimal immunologic alterations. No immunological effects were detected in PAT-exposed germ-free animals; indicating that microbiota are required for the observed activities. Transfer of PAT-perturbed microbiota led to delayed sIgA expression indicating that the altered microbiota is sufficient to transfer PAT-induced effects. PAT exposure had lasting and transferable effects on microbial community network structure. Together these results indicate the impact of a single therapeutic early-life antibiotic course altering the microbiota and modulating host immune phenotypes that persist long after exposure has ceased.