Exposure to Environmental Microbes Alters Responsiveness of Tadpole Gut Microbiome to Dietary Tannins.
Westcott RG, Rudzki EN, Emerson KJ, Woodley SK, Kohl KD
Plant Herbivore Interactions
PubMedTannins in the oak leaves, berry plants, and garden debris that fall into ponds and streams aren't just waste — they actively shape the health of the animals living there, but only when those animals are already bathed in the rich microbial life of a natural environment.
Tannins are natural chemicals found in many plants — think the bitterness in tea, red wine, or acorns — and tadpoles often eat plant material containing them. Researchers found that when tadpoles grew up in real pond water teeming with natural microbes, eating a tannin-rich diet actually reduced harmful bacteria in their guts. But tadpoles raised in sterilized lab water didn't get this benefit, showing that the surrounding microbial environment is essential for plants' chemical defenses to work as nature intended.
Key Findings
Tadpoles raised in natural pond water had greater body mass and length compared to those in sterilized water, though dietary tannins (2% tannic acid) had no effect on body size.
Gut bacterial diversity was significantly higher in tadpoles from natural pond water than in those from autoclaved (microbially depleted) water.
Dietary tannins reduced bacterial diversity and lowered the relative abundance of potentially pathogenic bacterial genera — but only in tadpoles raised in microbially rich natural water, not in sterile lab conditions.
chevron_right Technical Summary
Tadpoles raised in natural pond water — full of microbes — were larger and healthier, and their gut bacteria responded meaningfully to a tannin-rich diet, reducing potentially harmful bacteria. Tadpoles in sterile lab water showed none of these benefits, suggesting lab-only experiments miss key real-world biology.
Abstract Preview
Amphibian larvae consume variable diets in the wild, which can include tannin-rich plant material. Tannins are secondary metabolites that, when consumed, could have complex effects on herbivorous a...
open_in_new Read full abstract on PubMedAbstract copyright held by the original publisher.
Was this useful?
Ancient DNA Reveals Pre-Columbian Amazonian Forest Management at Scale
Forests and fruits we romanticize as wild — including many plants now in our kitchens and gardens — may exist in their current abundance precisely because an...