3.3 Gut fungal community variation in giant pandas after diet
conversion
After quality filtering and assembly, 7,172,982 fungal ITS sequences
were obtained from 108 fecal samples from the diet conversion
experiments. The sequences were clustered into 15,547 OTUs at the 97%
sequence identity threshold. Although richness and diversity varied with
diet conversions, significant differences in fungal community richness
and diversity were not observed among communities from the three
experimental groups (p > 0.05, ANOVA) (Figure 1a,
b). However, PCoA indicated that the communities from hosts with the
same diet clustered together and separately from others (Figure 1c).
Likewise, significant differences in community structure based on BC
distances were identified among the three groups (p <
0.05, AMOVA).
Ascomycota was the most dominant phyla among communities in the diet
conversion experiment, followed by Basidiomycota (Figure 1d).
Basidiomycota notably increased markedly in the OBD (41.9%) communities
relative to the OMD (7.6%) communities (Non-parametric factorial
Kruskal-Wallis sum-rank test, LDA>4) (Figure 1e). The 10
most abundant fungal genera in each group were further investigated,
excluding unidentified genera. Candida (37.0%),Saccharomyces (6.2%), and Microidium (6.1%) were the
three most abundant genera among communities of the OMD treatment.Candida (3.0%), Microidium (2.7%), andGibberella (1.0%) were the three most abundant genera in the MBD
communities. Lastly, Cystofilobasidium (9.0%), Guehomyces(8.1%), and Microidium (5.2%) were the three most abundant
genera in the OBD communities (Figure 1f). Candida abundances
were significantly higher in the OMD (37.0%) communities and were
significantly lower in the OMD (37.0%) to OBD (0.1%) communities
(Non-parametric factorial Kruskal-Wallis sum-rank test,
LDA>4) (Figure 1e, f). In addition,Cystofilobasidium , Guehomyces, and Gibberella were
significantly more abundant in the OBD communities (9.0%, 8.1%, and
2.8%, respectively) than in the OMD communities (0.03%, 0.0%, and
0.01%, respectively) (Non-parametric factorial Kruskal-Wallis sum-rank
test, LDA>4).