Aminomethylphosphonic Acid (AMPA), a Widespread Contaminant, Alters the Gut Microbiome of Larval Spined Toads Depending on Maternal Body Condition

Core Concepts

Exposure to the widespread environmental contaminant aminomethylphosphonic acid (AMPA) can alter the gut microbiome composition of larval spined toads, with the effects depending on maternal body condition.

Abstract

The study investigated the impact of AMPA exposure on the gut microbiome of spined toad (Bufo spinosus) tadpoles. Key findings:

AMPA exposure decreased the overall bacterial biomass in tadpole fecal samples, indicating a lower endogenous bacterial abundance.

AMPA affected the bacterial community composition of tadpole feces, but this effect depended on maternal body condition.

In tadpoles from females in better body condition, AMPA exposure decreased the abundance of the Bacteroidota phylum and increased the abundance of Actinobacteriota.

These AMPA-induced changes in the gut microbiome composition, particularly within the Bacteroidota and Actinobacteriota phyla, were not observed in tadpoles from females in poorer body condition.

The results suggest that maternal effects on early-life microbial colonizers can influence the response of the gut microbiome to environmental contaminants like AMPA.

The study highlights the importance of considering the gut microbiome when studying the effects of environmental pollutants on amphibian health and development.

Stats

AMPA exposure decreased the abundance of spiked-in bacterial controls in tadpole fecal samples compared to the control group, indicating an overall lower endogenous bacterial biomass.
AMPA exposure affected the composition of the tadpole fecal microbiome, with a stronger effect in offspring from females in better body condition.

Quotes

"AMPA exposure decreased the gut bacterial biomass and affected the bacterial community composition of tadpole's faeces."
"We observed interactions between AMPA exposure and maternal body condition on the Bacteroidota and Actinobacteriota phyla abundances."

Key Insights Distilled From

Maternal body condition affects the response of larval spined toads’ faecal microbiome to a widespread contaminant

by Tartu,S., Po... at www.biorxiv.org 12-18-2023

https://www.biorxiv.org/content/10.1101/2023.12.18.572122v4

Deeper Inquiries

How might the AMPA-induced changes in the gut microbiome composition impact the long-term health and fitness of the amphibian hosts?

The changes in the gut microbiome composition induced by AMPA exposure can have significant implications for the long-term health and fitness of amphibian hosts. The gut microbiome plays a crucial role in various physiological functions, including nutrient absorption, immune system regulation, and overall health maintenance. Therefore, alterations in the gut microbiota can lead to dysbiosis, affecting the host's ability to digest food, absorb essential nutrients, and maintain a healthy immune response.
In the case of amphibians, a disrupted gut microbiome can impact their growth, development, and overall fitness. For example, a decrease in beneficial bacteria such as Bacteroidota, which are involved in nutrient synthesis and metabolism, can lead to deficiencies in essential nutrients and energy production. This can result in stunted growth, delayed development, and reduced overall fitness in amphibian larvae.
Furthermore, changes in the gut microbiome composition can also affect the amphibian's susceptibility to diseases and environmental stressors. A dysbiotic gut microbiota may compromise the host's immune response, making them more vulnerable to infections and other health issues. Additionally, alterations in the gut microbiome can disrupt the balance of microbial communities, leading to an imbalance in the production of metabolites and signaling molecules that are essential for maintaining homeostasis.
Overall, the AMPA-induced changes in the gut microbiome composition can have far-reaching consequences for the long-term health and fitness of amphibian hosts, potentially impacting their growth, development, immune function, and overall survival in their natural habitats.

What other environmental factors or host characteristics could modulate the effects of AMPA on the gut microbiome in amphibians?

Several environmental factors and host characteristics can modulate the effects of AMPA on the gut microbiome in amphibians. These factors can interact with AMPA exposure to either exacerbate or mitigate the impact on the gut microbiota composition and overall health of the amphibian hosts. Some of the key factors include:

Habitat Type: The habitat in which amphibians reside can influence their exposure to AMPA and other environmental contaminants. Amphibians living in agricultural areas with high pesticide use may experience higher levels of AMPA exposure compared to those in natural or forested habitats.

Diet: The diet of amphibians can also play a role in modulating the effects of AMPA on the gut microbiome. Different dietary components can interact with AMPA and affect the composition of the gut microbiota. For example, a diet rich in fiber may support the growth of certain beneficial bacteria that can help mitigate the effects of AMPA exposure.

Genetic Factors: The genetic background of amphibians can influence their susceptibility to environmental contaminants like AMPA. Genetic variations in immune response, detoxification pathways, and gut microbiome composition can impact how individuals respond to AMPA exposure.

Age and Developmental Stage: The age and developmental stage of amphibians can also affect their response to AMPA exposure. Younger individuals or those in critical developmental stages may be more vulnerable to the effects of AMPA on the gut microbiome due to their developing immune system and metabolic processes.

Microbial Interactions: Interactions between different microbial species within the gut microbiome can also modulate the effects of AMPA exposure. Competition or cooperation between bacteria can influence the overall composition and function of the gut microbiota in response to environmental stressors.

By considering these environmental factors and host characteristics, researchers can gain a more comprehensive understanding of how AMPA exposure interacts with the gut microbiome in amphibians and identify potential strategies to mitigate the negative effects on host health.

Given the potential for vertical transmission of gut microbes, how might maternal exposure to AMPA prior to reproduction influence the microbiome and development of their offspring?

Maternal exposure to AMPA prior to reproduction can have profound effects on the microbiome and development of their offspring through vertical transmission of gut microbes. The maternal gut microbiota serves as a source of microbial colonizers for the developing embryos, influencing the initial composition of the offspring's gut microbiome. Therefore, any alterations in the maternal gut microbiome due to AMPA exposure can be passed on to the offspring, impacting their microbiome composition and subsequent development.
If a mother amphibian is exposed to AMPA, the changes in her gut microbiome can lead to dysbiosis, characterized by an imbalance in microbial communities. When the eggs are fertilized and develop, they acquire the maternal microbiota, potentially inheriting the dysbiotic microbial composition. This can affect the offspring's ability to digest food, absorb nutrients, and regulate their immune response from an early stage of development.
The altered gut microbiome in the offspring can have long-term consequences for their health and fitness. It may predispose them to certain health issues, compromise their immune system, and impact their growth and development. Additionally, the offspring may be less resilient to environmental stressors and more susceptible to diseases due to the dysbiotic gut microbiome inherited from the mother.
Overall, maternal exposure to AMPA can influence the microbiome and development of offspring through vertical transmission of gut microbes, highlighting the importance of considering the maternal environment and its effects on the next generation's health and fitness.