Effects of dispersal limitation in the face of intense selection via dietary intervention on the faecal microbiota of rats

Abstract

Four ecological processes mediate microbial diversity: selection, whereby host factors favour the persistence of particular microbial taxa; historical contingency, where differences in the timing and order of microbial acquisition results in different communities; stochastic factors that impact community assemblages; and dispersal limitation, where the presence of particular taxa is restricted by host population structure and local environmental factors. However, few studies have explored the impact of selection through diet modification on the differences in microbial community composition arising from dispersal limitation. At weaning, the faecal microbiota of 45 rats originating from six litters, as assessed by 16S rRNA gene sequencing, was strongly correlated with an animal's litter membership. Following 14 weeks on one of three the experimental diets, the faecal microbiota of the rats were again characterized. Clear effects of diet on microbial community composition were observed. However, after 14 weeks of dietary intervention, the effect of litter membership on microbial community composition was still significant. Our results demonstrate that intense selection (diet manipulation) cannot completely eliminate differences in microbial communities that occurred as a consequence of dispersal limitation (litter membership) prior to selection. These results have clear implications for efforts that attempt to achieve positive health outcomes through diet manipulation.

Maternal inheritance of the koala gut microbiome and its compositional and functional maturation during juvenile development

“…Furthermore, as one of those joeys suckled from several other mothers after pap feeding, it appears that this maternal effect is primarily produced by pap feeding and exposure during pouch life. This is consistent with studies in several other mammals that have found that exposure to maternal microbes during early development can shape the gut microbiome and, in some instances, can have a stronger effect on composition than diet (Daft et al ., 2015; Barron Pastor and Gordon, 2016; Treichel et al ., 2019). Our finding that joeys often had microbiomes that were most similar to a co‐habiting female (six out of eight joeys) suggests that, while pap feeding introduces many microbial groups, joeys may also acquire microbes horizontally through contact with other koalas and the environment.…”

The koala gut microbiome is largely unaffected by host translocation but rather influences host diet

“…Across a range of animal species, including humans, the gut microbiome has been found to change and adapt to variation in host diet (Hungate, 1966;David et al, 2014;Xu and Knight, 2015;Barron Pastor and Gordon, 2016). However, in hindgut fermenting herbivores such as the koala where much of the nutritious portion of the diet is absorbed in the small intestine prior to entering the caecum (Cork et al, 1999), the effect of diet on the hindgut and fecal microbiome may be more restricted.…”

Consumer feces impact coral health in guild-specific ways

“…The production of waste products is ubiquitous across the animal kingdom; this waste is a key component of nutrient cycles as well as an important way in which microbiota are transported throughout environments (5). Animal diets determine the composition of waste products, including their associated microbiota, and thus how the waste may affect other organisms in the environment (1,40,65). Testing how feces derived from animal species in diverse trophic guilds affect cohabitating organisms can inform agriculture, ecosystem management, and restoration.…”

“…As consumers-including herbivores, predators and parasites-move through the environment and engage in consumer-resource interactions, they transmit microorganisms amongst the animals and plants with which they interact (1)(2)(3). This trophic transmission likely has important implications for microbiota assembly, as well as for resource species health and environmental acclimatization (4)(5)(6).…”