A new study shows that the giant panda’s gut contains ‘Seasonal bacteria’ which helps it stay healthy throughout the year.
Researchers in China analysed the microbiota – the trillion-strong community of microorganisms in the gut – of giant pandas based on their faecal samples.
These results were found a bacterium called clostridium butyricumThe intestines also contain, and can boost the production of and the storage of fats in a short window when there are nutritious bamboo shoots available.
Giant pandas (Ailuropoda mylanoleuca), eat only fibrous bamboo. Yet, they remain healthy and chubby throughout the year.
This species was originally listed as endangered in 1990. After more than 30 years conservation efforts, its status was elevated to “vulnerable” in 2021.
Ailuropoda mega panda, (pictured), is a giant panda that eats only fibrous bamboo. However, they are still healthy and chubby through the entire year.
The research team at the Institute of Zoology, Chinese Academy of Sciences, Beijing has been studying wild giant pandas living in the Qinling Mountains in central China for decades.
Guangping Huang, the study’s author, stated that it was the first time that they had established a causal link between a panda’s gut microbiota type and its personality.
“We know that these pandas are more chubby during shoot-eating season. It’s obvious to us.
The giant panda lives mainly in temperate forests high in the mountains of southwest China, where they subsist almost entirely on bamboo — but the actual part of the bamboo that they eat depends on the time of year.
It lives on bamboo leaves for most of the year. But, during spring and summer, which are usually from April through August, they can enjoy new-sprouted shoots high in protein.
To determine how the annual changes in leaf-eating and shoot-eating seasons affected the bacteria levels in wild pandas’ faeces, researchers analysed samples of faecal material from eight pandas.
Wei indicated that the wild pandas had a higher concentration of Clostridium Butyricum (a bacterium) in their stomachs during the shoot-eating seasons than during the leaf-eating.
A faecal transplantation of wild panda feces to mice was performed by the team in an attempt to find out if the changes in microbiota might affect the panda’s metabolism.
The panda eats fibrous bamboo leaves throughout the year. The panda enjoys newly sprouted, high-protein bamboo shoots in the late spring and early fall (usually between late April and August).
The giant panda has a shift in its gut microbiota during the growing season of nutritious bamboo shoots. This helps it gain weight and store fat. A giant panda is seen enjoying a bamboo shot.
‘For endangered and vulnerable wild animals, we can’t really run tests on them directly,’ said Huang.
“Our research has created a model mouse for future faecal transplant studies that could be used to study the microbiota of wild animals.”
They then fed them a diet made of bamboo that mimicked what pandas consume for three weeks.
They found that mice who were transplanted using panda waste from shoot-eating seasons gained more weight than those with leaf-eating seasons faeces, and had less food.
Further analysis revealed that the metabolic product of C. butyricum – a short-chain fatty acid called butyrate – could upregulate the expression of a circadian rhythm gene called Per2, which increases lipid synthesis and storage.
The four-month-long shoot-eating season has a higher amount of C.butyricum, which allows pandas to gain weight and store fat more effectively. This may help to compensate for the low intake of nutrients during seasons with only bamboo leaves.
As a result, many animals feel a shift of gut bacteria during the winter months.
Illustration of the study. C. butyricum’s metabolic product (a short-chain, fat acid called butyrate), could be used to upregulate Per2 gene expression. This regulates lipid synthesis.
Some monkey species, like the one above, are able to have a different type of gut microbiota during summer when they can eat fresh fruits and vegetables than in winter when their diet consists of tree bark.
The Hadza, modern hunters-gatherers in Tanzania, also experience a similar shift as their food supply changes through the year.
The research team will continue to identify more microorganisms within the panda’s digestive system and learn about how they affect the animal’s health.
Huang explained that it was important to determine which bacteria is beneficial to animals in order for one day, probiotics may be used to treat some illnesses.
Cell Reports published the study.