CHENGDU - A study has shed new light on how bamboo, a fibrous plant, provides nutrition for giant pandas, which feed almost exclusively on it.

Researchers performed a large-scale genome sequencing study of the gut microbes of pandas, which have a digestive tract similar to carnivores.

They found that the gut microbes do not significantly contribute to the degradation of cellulose and lignin, which are abundant in bamboo. The finding suggests that the animals do not depend on cellulose or lignin to obtain energy. Instead, they rely on starch and hemicelluloses in the plant.

Giant pandas have a higher capability for digesting starch than strict carnivores do. They develop an increasing ability to digest starch following the dietary transition from mother's milk to bamboo, the study found.

The animals have much higher ability to digest hemicellulose than cellulose, and they prefer bamboo shoots, tender leaves and first-year bamboo, all of which have an abundance of hemicelluloses.

Since a sufficient quantity of bamboo shoots is important for providing energy during breeding activities, researchers say that more attention should be paid to protecting bamboo shoots during the mating and childbirth seasons of giant pandas in the wild.

"Giant pandas love bamboo partly because it is everywhere in their habitats, and they have few competitors," said Zhang Wenping, the first author of the research paper and a researcher at the Chengdu Research Base of Giant Panda Breeding in Sichuan province.

In addition, relative to other woody plants bamboo has high levels of starch, Zhang said.

The research paper was published in The ISME Journal earlier this month.

Xinhua