MicroRNAs play an important role as post-transcriptional regulators in many biological processes, including metabolism. Recent research shows that microRNAs can be exchanged between organisms via exosome transport. This exchange can also take place ‘cross-kingdom’, i.e. between plants and animals. In a study of giant pandas in the wild, researchers at China West Normal University in Nanchong found exosomes in blood samples. MicroRNAs were found in these exosomes.

By comparing the microRNAs from the blood samples with microRNA from bamboo shoots, stems and leaves, the researchers found that 57 strands matched between the samples. This shows that microRNA from food can enter the body and is not always released through the intestinal tract.

So what exactly does this microRNA do in the body? It turns out that microRNAs can bind to genes involved in taste and smell signal transduction, digestion and nutrient absorption, hormonal pathways and dopamine metabolism. The microRNA thus has impact on a lot of biological processes.

These insights give a new direction to the mystery of the giant panda’s dietary choices. The less nutritious bamboo diet and the microRNAs derived from it seem to play a major role in its preferences. This occurs through the panda’s perception of taste and smell and the internal reward system.

It is too early for strong conclusions. This is because the group of pandas studied consisted of only seven giant pandas living in the wild, because of their protected status. In the accompanying press release, research leader Feng Li says they ‘would also like to analyse blood samples from very young pandas that have not yet eaten bamboo’. This will probably be even more difficult – but also much cuter.

Tan, H. et al (2025) Front. Vet. Sci., DOI: 10.3389/fvets.2025.1509698