Environmental arsenic exposure and the human gut microbiome
Abstract/Contents
- Abstract
- Arsenic contamination of drinking water is a global environmental issue and public health crisis. In the US, 13 million people are exposed to levels exceeding US Water Quality Standards, and in Bangladesh, more than 25 million people are chronically exposed. Chronic ingestion can lead to arsenicosis, a disease with no effective treatment. By studying the role of the microbiome in arsenic metabolism, we aim to broaden traditional risk assessment to incorporate consideration of host-associated microbiota. Our hypothesis is that arsenic ingestion alters the structure and function of gut microbiota and that differences in the microbiota contribute to observed variations in presence of arsenicosis, given similar exposures. Anaerobic bioreactors were employed to characterize the effects of exogenous arsenic on gut microbiota samples and their transformations of arsenic. We observed interindividual variability in As(V) to As(III) conversion rates, methylation, and thiolation, with differences between Bangladeshi and Palo Alto cohorts. These results illustrate the potential biotransformative capability of the gut microbiome and variation within and across cohorts. PCoA of 16S rDNA sequencing data shows clustering by subject and cohort, with the exception of a Palo Alto Nepali male whose samples cluster with the Bangladeshi cohort. There is a temporal gradient in taxonomic composition over time for some individuals' bioreactors. Taxa were identified that drive variance within cohort groups, with variance in Bangladeshi stool correlated with exposure and arsenic disease state, nail arsenic, and urinary arsenic. Correlations between microbiome structure and differences in biotransformation and/or disease state could lead to novel management strategies and interventions for communities exposed to arsenic.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2021; ©2021 |
| Publication date | 2021; 2021 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Bachas-Daunert, Stephanie Maria |
|---|---|
| Degree supervisor | Criddle, Craig |
| Thesis advisor | Criddle, Craig |
| Thesis advisor | Fendorf, Scott |
| Thesis advisor | Relman, David A |
| Degree committee member | Fendorf, Scott |
| Degree committee member | Relman, David A |
| Associated with | Stanford University, Civil & Environmental Engineering Department |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Stephanie Bachas-Daunert. |
|---|---|
| Note | Submitted to the Civil & Environmental Engineering Department. |
| Thesis | Thesis Ph.D. Stanford University 2021. |
| Location | https://purl.stanford.edu/xc546rn2188 |
Access conditions
- Copyright
- © 2021 by Stephanie Maria Bachas-Daunert
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