Parasite-Microbiota Interactions With the Vertebrate Gut: Synthesis Through an Ecological Lens

Abstract

The vertebrate gut teems with a large, diverse, and dynamic bacterial community that has pervasive effects on gut physiology, metabolism, and immunity. Under natural conditions, these microbes share their habitat with a similarly dynamic community of eukaryotes (helminths, protozoa, and fungi), many of which are well-known parasites. Both parasites and the prokaryotic microbiota can dramatically alter the physical and immune landscape of the gut, creating ample opportunities for them to interact. Such interactions may critically alter infection outcomes and affect overall host health and disease. For instance, parasite infection can change how a host interacts with its bacterial flora, either driving or protecting against dysbiosis and inflammatory disease. Conversely, the microbiota can alter a parasite's colonization success, replication, and virulence, shifting it along the parasitism-mutualism spectrum. The mechanisms and consequences of these interactions are just starting to be elucidated in an emergent transdisciplinary area at the boundary of microbiology and parasitology. However, heterogeneity in experimental designs, host and parasite species, and a largely phenomenological and taxonomic approach to synthesizing the literature have meant that common themes across studies remain elusive. Here, we use an ecological perspective to review the literature on interactions between the prokaryotic microbiota and eukaryotic parasites in the vertebrate gut. Using knowledge about parasite biology and ecology, we discuss mechanisms by which they may interact with gut microbes, the consequences of such interactions for host health, and how understanding parasite-microbiota interactions may lead to novel approaches in disease control.

Human gut microbiota networks disturbance by parasites in indigenous communities: Effect on bacteria genera related to depression incidence subnetworks

“…Hence, the physiological mechanisms involved in these behavioral changes being adaptive for the parasite or not, may include hormonal 6 , immunological 7 and neurological components 8 . Nevertheless, these three levels of physiological signaling are not only regulated by parasites, but also by other microorganisms like bacterial microbiota, that coexist in the same host's internal environment 9 .…”

“…In this sense, host's behavioral changes might be viewed as the result of the complex communication network between macro and microorganisms that have the ability to modify these host's physiological axis 9 . Moreover, the presence of certain bacterial communities should also impact the establishment of parasites and vice versa, parasites could be modifying the bacterial microbiota composition 9 .…”

“…In this sense, host's behavioral changes might be viewed as the result of the complex communication network between macro and microorganisms that have the ability to modify these host's physiological axis 9 . Moreover, the presence of certain bacterial communities should also impact the establishment of parasites and vice versa, parasites could be modifying the bacterial microbiota composition 9 . This bidirectional relation is plausible if both groups compete for similar host's resources, such as a specific nutrient or an ecological niche, or because the activation of the host's immune response due to the presence of parasites, disrupting different homeostatic relations established between bacterial microbiota and its host 10 .…”

Disturbance in human gut microbiota networks by parasites and its implications in the incidence of depression

“…These changes are mediated by physiological mechanisms that include hormonal 3 , immunological 4 and neurological components 5 . Nevertheless, these physiological levels may also be regulated by other microorganisms like bacterial microbiota that coexist in the same host's internal environment 6 . In this sense, the host's behavioral changes might be viewed as the result of the complex communication network between macro and microorganisms that have the ability to modify the mentioned host's physiological axis 6 .…”

“…Nevertheless, these physiological levels may also be regulated by other microorganisms like bacterial microbiota that coexist in the same host's internal environment 6 . In this sense, the host's behavioral changes might be viewed as the result of the complex communication network between macro and microorganisms that have the ability to modify the mentioned host's physiological axis 6 . Moreover, the presence of certain bacterial communities should also impact the establishment of parasites and vice versa, parasites could be modifying the bacterial microbiota composition.…”