Changes in Gut Microbiota Composition Associated with the Presence of Enteric Protist Blastocystis in Captive Forest Musk Deer (Moschus Berezovskii)

Abstract

Blastocystis is a common protistan parasite inhabiting the gastrointestinal tract of a wide range of hosts including humans and domestic and wild animals. Many studies have revealed the associations between Blastocystis and gut microbiome in humans. However, only a few studies have focused on the associations between Blastocystis and gut microbiome of animals, especially in forest musk deer (Moschus berezovskii). We investigated the effects of the Blastocystis colonization on the intestinal bacterial community compositions using amplicon sequencing targeting the V4 variable region of the 16S rRNA. Two subtypes of Blastocystis (ST5 and ST10) and Blastocystis-free (control) were included in this study. We found that compared with the forest musk deer without Blastocystis, ST10-colonized forest musk deer had higher bacterial richness and diversity, while ST5-colonized forest musk deer showed a comparable bacterial diversity. Likewise, beta diversity revealed significant differences in bacterial community structure between ST10-colonized and Blastocystis-free forest musk deer. The proportion of Bacteroidetes were significantly enriched in ST10-colonized forest musk deer. Bacterial community structure between ST5-colonized and Blastocystis-free forest musk deer did not differ significantly. The present study explored the associations between Blastocystis and gut microbial community of forest musk deer for the first time, and revealed ST10 colonization, instead of ST5, is associated with higher bacterial diversity and shifted microbial structure. Our data provides valuable insights into the associations between gut microbiomes and parasites. IMPORTANCE Forest musk deer is listed as an endangered species by International Union for Conservation of Nature Red List, and the Chinese government has introduced captivity breeding measures to curb the rapid decline of the musk deer population since the 1950s. It has been suggested that Blastocystis colonization can modulate the composition of the host's intestinal microbiota, thereby affecting the host health. The present study investigated the effects of the Blastocystis colonization on the gut microbiota in the feces of forest musk deer in Sichuan Province, China. Two subtypes (ST5 and ST10) have differential effects on the bacterial diversity and community composition, suggesting that the study of Blastocystis should be distinguished at the subtype level. Because the pathogenicity of Blastocystis is controversial, pathogenic, or commensal, continuous monitoring of the impact of Blastocystis colonization on the intestinal microbiota is of great significance to assess its health effects on forest musk deer.

Keywords: Blastocystis; captive management; conservation; forest musk deer; gut microbiome; wildlife disease.

FIG 1

Comparison of alpha diversity of gut microbiota from the Blastocystis-colonized and Blastocystis-free groups based on Observed species, Pielou's evenness, and Shannon indexes (A). Comparison of alpha diversity of gut microbiota from the Blastocystis-free, and ST10-colonzed groups (B). B-: Blastocystis-free forest musk deer; ST10: ST10-colonized forest musk deer.

FIG 2

Beta-diversity analysis using PCoA based on Weighted Unifrac distance. Each point in the figure represents a sample, and points of different colors indicate different groups.

FIG 3

UpSet plot shows the numbers of ASVs that were shared or not shared by Blastocystis-free, ST10-colonized, ST5-colonized forest musk deer.

FIG 4

Relative abundance of the 19 phyla (A). Relative abundance (mean ± SD) of 10 major bacterial phyla (B) Blastocystis-free, ST10-colonized, and ST5-colonized forest musk deer. Wilcoxon rank-sum test. *, P < 0.05, * *, P < 0.01.

FIG 5

(A and B) Proportion of sequences assigned to each main group at the genus level, along with the means for each group and significance of difference in mean proportions using STAMP. Significant differences (P value < 0.05) are represented here between the two main groups (Welch’s t test, two-sided).

FIG 6

Differentially abundant bacterial taxa among the Blastocystis-free, ST10-colonized, ST5-colonized groups. Taxa with significantly differences in different groups were detected by LEfSe analysis (A). Cladogram generated by LEfSe indicating differentially abundant bacterial taxa (B).