Gastrointestinal dysbiosis following diethylhexyl phthalate exposure in zebrafish (Danio rerio): Altered microbial diversity, functionality, and network connectivity

• Published in: Environmental pollution (1987) Vol. 265; p. 114496
• Main Authors: Buerger, Amanda N., Dillon, David T., Schmidt, Jordan, Yang, Tao, Zubcevic, Jasenka, Martyniuk, Christopher J., Bisesi, Joseph H.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2020
• Subjects: Gastrointestinal system; Microbiome; Network analysis; Obesity; Phthalates; Zebrafish; Obesity; Zebrafish; Gastrointestinal system; Network analysis; Phthalates; Microbiome
• DOI: 10.1016/j.envpol.2020.114496
• ISSN: 0269-7491

Microbiome community structure is intimately involved in key biological functions in the gastrointestinal (GI) system including nutrient absorption and lipid metabolism. Recent evidence suggests that disruption of the GI microbiome is a contributing factor to metabolic disorders and obesity. Poor diet and chemical exposure have been independently shown to cause disruption of the GI microbiome community structure and function. We hypothesized that the addition a chemical exposure to overfeeding exacerbates adverse effects on the GI microbiome community structure and function. To test this hypothesis, adult zebrafish were fed a normal feeding regime (Control), an overfeeding regime (OF), or an overfeeding regime contaminated with diethylhexyl phthalate (OF + DEHP), a suspected obesogen-inducing chemical. After 60 days, fecal matter was collected for sequencing, identification, and quantification of the GI microbiome using the 16s rRNA hypervariable region. Analysis of beta diversity indicated distinct microbial profiles between treatments with the largest divergence between Control and OF + DEHP groups. Based upon functional predictions, OF + DEHP treatment altered carbohydrate metabolism, while both OF and OF + DEHP affected biosynthesis of fatty acids and lipid metabolism. Co-occurrence network analysis revealed decreases in cluster size and a fracturing of the microbial community network into unconnected components and a loss of keystone species in the OF + DEHP treatment when compared to Control and OF treatments. Data suggest that the addition of DEHP in the diet may exacerbate microbial dysbiosis, a consequence that may explain in part its role as an obesogenic chemical. [Display omitted] •Zebrafish were co-exposed to overfeeding and diethylhexyl phthalate (DEHP).•Microbial profiles were distinct following co-exposure or overfeeding alone.•Predicted microbial functional profiles differed between treatment groups.•Microbial networks were fragmented following overfeeding with DEHP. Co-treatment of overfeeding with DEHP results in distinct microbial profiles characterized by alterations in diversity, function, and microbial network ecology, which may contribute to obesogenic mechanisms in the host.