Associations of Childhood and Perinatal Blood Metals with Children’s Gut Microbiomes in a Canadian Gestation Cohort

Background: The gut microbiome is important in modulating health in childhood. Metal exposures affect multiple health outcomes, but their ability to modify bacterial communities in children is poorly understood.Objectives: We assessed the associations of childhood and perinatal blood metal levels with childhood gut microbiome diversity, structure, species, gene family-inferred species, and potential pathway alterations.Methods: We assessed the gut microbiome using 16S rRNA gene amplicon sequencing and shotgun metagenomic sequencing in stools collected from 6- to 7-year-old children participating in the GESTation and Environment (GESTE) cohort study. We assessed blood metal concentrations [cadmium (Cd), manganese (Mn), mercury (Hg), lead (Pb), selenium (Se)] at two time points, namely, perinatal exposures at delivery (N=70) and childhood exposures at the 6- to 7-y follow-up (N=68). We used multiple covariate-adjusted statistical models to determine microbiome associations with continuous blood metal levels, including linear regression (Shannon and Pielou alpha diversity indexes), permutational multivariate analysis of variance (adonis; beta diversity distance matrices), and multivariable association model (MaAsLin2; phylum, family, species, gene family-inferred species, and pathways).Results: Children’s blood Mn and Se significantly associated with microbiome phylum [e.g., Verrucomicrobiota (coef=−0.305, q=0.031; coef=0.262, q=0.084, respectively)] and children’s blood Mn significantly associated with family [e.g., Eggerthellaceae (coef=−0.228, q=0.052)]-level differences. Higher relative abundance of potential pathogens (e.g., Flavonifractor plautii), beneficial species (e.g., Bifidobacterium longum, Faecalibacterium prausnitzii), and both potentially pathogenic and beneficial species (e.g., Bacteriodes vulgatus, Eubacterium rectale) inferred from gene families were associated with higher childhood or perinatal blood Cd, Hg, and Pb (q<0.1). We found significant negative associations between childhood blood Pb and acetylene degradation pathway abundance (q<0.1). Finally, neither perinatal nor childhood metal concentrations were associated with children’s gut microbial inter- and intrasubject diversity.Discussion: Our findings suggest both long- and short-term associations between metal exposure and the childhood gut microbiome, with stronger associations observed with more recent exposure. Future epidemiologic analyses may elucidate whether the observed changes in the microbiome relate to children’s health. https://doi.org/10.1289/EHP9674     

Long-term PM2.5 exposure before diagnosis is associated with worse outcome in breast cancer

Breast Cancer Research and Treatment - Many patients seek breast reconstruction following mastectomy. Debate exists regarding the best reconstructive option. The authors evaluate outcomes comparing...     

Is this environment making you older? Molecular biomarkers and new approaches to investigate the influences of environmental chemicals through aging

Aging is characterized by a gradual and progressive decline in system integrity that occurs with advancing chronological age. Although it is a physiological process, aging is associated with a myriad of age-related diseases (ARDs), including frailty, sarcopenia, chronic obstructive pulmonary disease, cardiovascular disease, cancer, and neurodegenerative diseases. While not exclusively ARDs, many of these diseases lead to death, a lesser quality of life, and increased healthcare costs for individuals and systems. ARDs share several underlying molecular mechanisms, such as cellular damage, inflammation, DNA methylation changes, stem cells exhaustion, and DNA mutations, which have been outlined as hallmarks of aging. Evidence suggests that environmental exposures, including but not limited to metals, air pollution, endocrine-disrupting chemicals, and noise, may accelerate biological aging. Over the past few years, aging research has identified new molecular biomarkers of the aging process. When applied to investigate environmental influences, these biomarkers can help identify individuals who are particularly susceptible to the influences of environmental exposures on aging processes and therefore guide in implementing possible preventive measures.