In collaboration with researchers from the Queen Mary University of London and the University of Oulu, Finland, scientists from Jiangnan University, China, led a study that showed a species of gut bacteria, known as Lactobacillus apis, is linked to enhanced memory in bumblebees.
The researchers show that bumblebees with more of this type of bacteria in their guts have a better memory than those with fewer bacteria.
Also, long-lasting improvised memories were observed in Bumblebees who ate food containing more of this species of gut bacteria than bumblebees with a regular diet.
The study, published in the journal Nature Communications, adds to growing evidence that the gut microbiome – the trillions of microbes that live in our intestines – can affect animal behavior.
Researchers used different colored artificial flowers to study bees’ memory and learning abilities. Five colors were associated with the sweet sucrose solution. The other five were with a bitter-tasting solution containing quinine, a repellent for bees.
The researchers observed that the bees were quickly able to learn which colors were associated with a sugar reward and if they could retain this information in a follow-up test three days later. They compared individual differences in bumblebees’ learning and memory abilities with the levels of different bacteria found in their gut post-sequencing gut samples from bees.
The researchers added these bacteria to the bumblebees’ diet to confirm that the numbers of Lactobacillus apis in the gut were directly responsible for the observed differences in memory. They measured their responses to the same task.
Bees’ cognitive abilities vary across individuals. They have a relatively small community of gut microorganisms compared with mammals. This makes them ideal models to explore the role of specific gut bacteria on differences in cognition between individuals.
The researchers suggest that observed variations in the microbiome across individual bumblebees could arise from differences or changes in nest environment, activities, pathogens, social interactions, and pollination environment.
- Li, L., Solvi, C., Zhang, F. et al. Gut microbiome drives individual memory variation in bumblebees. Nat Commun 12, 6588 (2021). DOI: 10.1038/s41467-021-26833-4