Age-related differences in the cloacal microbiota of a wild bird species

Abstract

BackgroundGastrointestinal bacteria play a central role in the health of animals. The bacteria that individuals acquire as they age may therefore have profound consequences for their future fitness. However, changes in microbial community structure with host age remain poorly understood. We characterised the cloacal bacteria assemblages of chicks and adults in a natural population of black-legged kittiwakes (Rissa tridactyla), using molecular methods.ResultsWe show that the kittiwake cloaca hosts a diverse assemblage of bacteria. A greater number of total bacterial OTUs (operational taxonomic units) were identified in chicks than adults, and chicks appeared to host a greater number of OTUs that were only isolated from single individuals. In contrast, the number of bacteria identified per individual was higher in adults than chicks, while older chicks hosted more OTUs than younger chicks. Finally, chicks and adults shared only seven OTUs, resulting in pronounced differences in microbial assemblages. This result is surprising given that adults regurgitate food to chicks and share the same nesting environment.ConclusionsOur findings suggest that chick gastrointestinal tracts are colonised by many transient species and that bacterial assemblages gradually transition to a more stable adult state. Phenotypic differences between chicks and adults may lead to these strong differences in bacterial communities. These data provide the framework for future studies targeting the causes and consequences of variation in bacterial assemblages in wild birds.

Influence of Hand Rearing and Bird Age on the Fecal Microbiota of the Critically Endangered Kakapo

“…The lack of differentiation between juvenile and adult community structures is an interesting finding, as strong differences have been reported for other avian systems in which the juveniles were of an age similar to (32,36) or older than (33) the juveniles studied here. Despite the lack of difference in community structure, some OTUs varied significantly in abundance between younger and older birds, likely reflecting at least some role of bird age in shaping the microbiota.…”

“…Previous research into the development of the gut microbiota in other host species has shown that the microbiota of juveniles differs significantly from that of adults in both avians and mammals (32)(33)(34)(35)(36), although it is not clear whether this pattern is reflected in the kakapo (12). In many avian species, the juvenile microbiota is a dynamically changing community (37-39) that gradually develops toward the adult community structure (33,36), but the changes in microbiota as the subject ages vary by host. For example, chickens are enriched in Lactobacillaceae in the first week of life (38), while juvenile turkeys appear to harbor a large proportion of Clostridiales until around 10 weeks of age (39).…”

Similarities and seasonal variations in bacterial communities from the blood of rodents and from their flea vectors

“…However, the fact that bacterial communities in all gerbil groups have passed through similar seasonal changes suggest that these changes may not be linked to changes in the internal environment of the host. Other studies reported that microbial communities show high variability between host individuals, age groups and sexes and/or a relatively high temporal stability (Moran et al, 2005;Costello et al, 2009;Godoy-Vitorino et al, 2010;Oh et al, 2012;Yatsunenko et al, 2012;Faith et al, 2013;van Dongen et al, 2013;Kueneman et al, 2014;Leclaire et al, 2014). The lack of interindividual variations in the composition of bacterial communities in our study may result from the transmission of fleas between hosts via direct interactions, replacement of burrows or free dispersal (Krasnov, 2008).…”

“…Nevertheless, because vector-borne microbes spend a part of their lives in the blood of the vertebrate host, it is important to consider also the internal environment of this host. For instance, microbes in the bloodsimilar to other microbes in the vertebrate gut, secretion glands, plumage, cloaca and skin-may be influenced by host species, diet, personality, body mass, sex, age and health status (see, for example, Alexy et al, 2003;Voigt et al, 2005;Fierer et al, 2008;Turnbaugh et al, 2009;Martin et al, 2010;Koenig et al, 2011;Muegge et al, 2011;Roeselers et al, 2011;Saag et al, 2011;Yatsunenko et al, 2012;Faith et al, 2013;van Dongen et al, 2013;Gavish et al, 2014;Kedem et al, 2014;Kueneman et al, 2014;Leclaire et al, 2014).…”

Phylogenetic and Functional Alterations in Bacterial Community Compositions in Broiler Ceca as a Result of Mannan Oligosaccharide Supplementation

“…Host physiology has been shown to have an impact on the development of the gastrointestinal microbiota (32). It is also likely that age-related differences arise due to a number of other factors, including resource competition between bacterial species, shifts in the host's diet, or agerelated variation in the chemical and physiological state of the gastrointestinal tract (33). Broilers are harvested at a relatively young age, approximately 42 days posthatch.…”