Divergent Response of Host-Specific Driven Gut Microbial Stability in Freshwater Gastropods to Cyanobacterial Blooms

Gut microbial community stability is critical for host environmental adaptation. Cyanobacteria have been shown to disrupt the gut microbial composition, which can lead to gut microbiota dysbiosis. However, little is known about the effects of cyanobacteria on the stability of gut microbial communities in different hosts. In this study, two freshwater gastropods (Bellamya aeruginosa and Pomacea canaliculata) were used as controls to study the differences in the effects of cyanobacteria on their gut microbial communities in ponds with the absence of cyanobacterial blooms. Cyanobacterial blooms cause distinct differences in the diversity, community structure, and assembly mechanisms of gut microbiota between the two freshwater gastropod species. The gut microbiota of B. aeruginosa exhibits significantly lower robustness (p < 0.01) and greater vulnerability under cyanobacterial exposure, indicating reduced community stability, whereas canaliculata exhibits greater adaptive capacity. Microbial co-occurrence networks suggest that cyanobacteria influence potential interactions within the gut microbial community of B. aeruginosa, and that the number of potential keystone taxa that maintain community stability is low in water bodies with occurrences of cyanobacterial bloom. This study reveals the differential response of the gut microbial community stability to cyanobacterial blooms in different snail hosts, providing new perspectives for understanding the adaptation mechanisms of gastropods to environmental stresses.