Do diet and taxonomy influence insect gut bacterial communities?

Abstract

Many insects contain diverse gut microbial communities. While several studies have focused on a single or small group of species, comparative studies of phylogenetically diverse hosts can illuminate general patterns of host-microbiota associations. In this study, we tested the hypotheses that (i) host diet and (ii) host taxonomy structure intestinal bacterial community composition among insects. We used published 16S rRNA gene sequence data for 58 insect species in addition to four beetle species sampled from the Sevilleta National Wildlife Refuge to test these hypotheses. Overall, gut bacterial species richness in these insects was low. Decaying wood xylophagous insects harboured the richest bacterial gut flora (102.8 species level operational taxonomic units (OTUs)/sample ± 71.7, 11.8 ± 5.9 phylogenetic diversity (PD)/sample), while bees and wasps harboured the least rich bacterial communities (11.0 species level OTUs/sample ± 5.4, 2.6 ± 0.8 PD/sample). We found evidence to support our hypotheses that host diet and taxonomy structure insect gut bacterial communities (P < 0.001 for both). However, while host taxonomy was important in hymenopteran and termite gut community structure, diet was an important community structuring factor particularly for insect hosts that ingest lignocellulose-derived substances. Our analysis provides a baseline comparison of insect gut bacterial communities from which to test further hypotheses concerning proximate and ultimate causes of these associations.

The Role of Host Phylogeny Varies in Shaping Microbial Diversity in the Hindguts of Lower Termites

“…Similar to recent investigations of lower termites (6,(18)(19)(20)(21), the bacterial communities were dominated by a combination of Bacteroidetes (34.7% of the sequences and 15.5% of the OTUs), Endomicrobia (Elusimicrobia) (14.7 and 4.0%), and Spirochaetes (18.4 and 28.4%) (Fig. 2C and D).…”

“…Recent studies have described the bacterial diversity in the hindguts of Cryptocercus cockroaches and a limited representation of lower and higher termites (6,(18)(19)(20)(21). Like the protists, the diversity of bacteria is distinct, unique, and consistent compared to other insect gut communities, and historical effects also appear to have played a role in their community structure (18)(19)(20). Bacterial diversity, however, has neither been surveyed across the lower termites nor in con-junction with the protists to compare the relative influence of historical effects on community structure in these two groups of microorganisms.…”

Gut bacterial communities across tadpole ecomorphs in two diverse tropical anuran faunas

“…The combined influence of these factors agrees with the situation in other animals, such as 620 insects (Colman et al 2012). The data presented here indicate species-specific differences in 621 …”

The holobiont concept: the case of xylophagous termites and cockroaches

“…All endogenous (provided by the termite) GH are affiliated with the glycoside hydrolase family (GHF) 9, and GHF1 (Ni and Tokuda 2013). The hindgut microbiota of insects is largely structured by exogenous (diet and local environment) and endogenous (gut environment) factors (Colman et al 2012;Tai et al 2014;Yun et al 2014), but a dynamic core gut microbiota (commensal/symbiotic) were maintained even after environmental shifts ( Schauer et al 2014;Makonde et al 2015). Figure 4 shows the gut microbial composition at phylum level of several wood-feeding insect, including two omnivores' cockroaches.…”