Updated publication reference for PubMed record(s): 32300339. The iconic giant panda is an endangered species known worldwide for its peculiar dietary habits. While retaining the digestive system of a carnivore, the giant panda successfully moved into a diet almost exclusively based on bamboo. Digestion of lignocellulose is believed to be conducted solely by its gut microbiome, provided that no lignocellulose-degrading enzyme was found in the giant panda’s genome. Many reports focused on which lignocellulose component feeds the giant panda, while little effort was made to link the products of bamboo fermentation to the panda’s dietary choices. In the present study, fermentation of either green leaves or yellow pith was conducted in the laboratory using gut microbiomes derived from either green or yellow stools, respectively. Green leaves were fermented to ethanol, lactate and acetate, while yellow pith to lactate resembling, respectively, hetero/homo-fermentation patterns. Several microbial pathways (assessed by metaproteomics) related to hemicellulose rather than cellulose degradation. However, alpha-amylases (E.C. 3.2.1.1) from the giant panda itself were the most predominant enzyme (up to 60% of all metaproteins), indicating that they have a primary role in bamboo digestion. The distinct fermentation profiles resulting from digestion of selected portions of bamboo may be part of the feeding strategy of giant pandas.