A survey of alternative diet strategies and gut microbiota of Australian native dung beetles (Scarabaeinae)

Gut microbes play an important role in the biology and evolution of insects. Australian native dung beetles (Scarabaeinae) present an opportunity to study gut microbiota in an evolutionary context as they come from two distinct phylogenetic lineages and some species in each lineage have secondarily adapted to alternative or broader diets. In this study, we characterised the hindgut bacterial communities found in 21 species of dung beetles across two lineages using 16S rRNA sequencing. We found that gut microbial diversity was more dependent on host phylogeny and gut morphology than specific dietary preferences or environment. In particular, gut microbial diversity was highest in the endemic, flightless genus Cephalodesmius that feeds on a broad range of composted organic matter. The hindgut of Cephalodesmius harbours a highly conserved core set of bacteria suggesting that the bacteria are symbiotic. Symbiosis is supported by the persistence of the core microbiota across isolated beetle populations and between species in the genus. A co-evolutionary relationship is supported by the expansion of the hindgut to form a fermentation chamber and the fermentative nature of the core microbes. In contrast, Australian species of the widespread dung beetle genus Onthophagus, specialise on a single food resource such as dung or fungus, exhibit minimal food processing behaviour, have a short, narrow hindgut and a variable gut microbiota with relatively few core bacterial taxa. A conserved, complex gut microbiota is hypothesised to be unnecessary for this highly mobile genus.IMPORTANCE Dung beetles are a very important part of an ecosystem because of their role in the removal and decomposition of vertebrate dung. It has been suspected that symbiotic gut bacteria facilitate this role, a hypothesis that we have explored with high throughput barcoding. We found that differences in hindgut morphology had the greatest effect on the bacterial community composition. Species with a hindgut fermentation chamber harboured a distinctly different hindgut community compared to those species with a narrow, undifferentiated hindgut. Diet and phylogeny were also associated with differences in gut community. Further understanding of the relationships between dung beetles and their gut microbes will provide insights into the evolution of their behaviours and how gut communities contribute to their fitness.

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Review for "Gut microbiota alterations affect glioma growth and innate immune cells involved in tumor immunosurveillance in mice"

10.1002/eji.201948354/v2/review1 ◽

2020 ◽

Keyword(s):

Gut Microbiota ◽

Immune Cells ◽

Innate Immune ◽

Innate Immune Cells ◽

Tumor Immunosurveillance ◽

Glioma Growth

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Decision letter for "Gut microbiota alterations affect glioma growth and innate immune cells involved in tumor immunosurveillance in mice"

10.1002/eji.201948354/v2/decision1 ◽

2020 ◽

Keyword(s):

Gut Microbiota ◽

Immune Cells ◽

Innate Immune ◽

Innate Immune Cells ◽

Tumor Immunosurveillance ◽

Glioma Growth

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Review for "Gut microbiota alterations affect glioma growth and innate immune cells involved in tumor immunosurveillance in mice"

10.1002/eji.201948354/v1/review2 ◽

2019 ◽

Keyword(s):

Gut Microbiota ◽

Immune Cells ◽

Innate Immune ◽

Innate Immune Cells ◽

Tumor Immunosurveillance ◽

Glioma Growth

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Review for "Gut microbiota alterations affect glioma growth and innate immune cells involved in tumor immunosurveillance in mice"

10.1002/eji.201948354/v1/review1 ◽

2019 ◽

Keyword(s):

Gut Microbiota ◽

Immune Cells ◽

Innate Immune ◽

Innate Immune Cells ◽

Tumor Immunosurveillance ◽

Glioma Growth

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Folate and vitamin B-12 deficiencies additively impaired memory function and disturbed the gut microbiota in amyloid-β infused rats

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000624 ◽

2019 ◽

pp. 1-13 ◽

Cited By ~ 2

Author(s):

Sunmin Park ◽

Sunna Kang ◽

Da Sol Kim

Keyword(s):

Insulin Resistance ◽

Gut Microbiota ◽

Insulin Signaling ◽

Gut Microbiome ◽

Metabolic Diseases ◽

Memory Function ◽

Amyloid Β ◽

Impaired Memory ◽

Ca1 Region ◽

Folate And Vitamin B12

Abstract. Folate and vitamin B12(V-B12) deficiencies are associated with metabolic diseases that may impair memory function. We hypothesized that folate and V-B12 may differently alter mild cognitive impairment, glucose metabolism, and inflammation by modulating the gut microbiome in rats with Alzheimer’s disease (AD)-like dementia. The hypothesis was examined in hippocampal amyloid-β infused rats, and its mechanism was explored. Rats that received an amyloid-β(25–35) infusion into the CA1 region of the hippocampus were fed either control(2.5 mg folate plus 25 μg V-B12/kg diet; AD-CON, n = 10), no folate(0 folate plus 25 μg V-B12/kg diet; AD-FA, n = 10), no V-B12(2.5 mg folate plus 0 μg V-B12/kg diet; AD-V-B12, n = 10), or no folate plus no V-B12(0 mg folate plus 0 μg V-B12/kg diet; AD-FAB12, n = 10) in high-fat diets for 8 weeks. AD-FA and AD-VB12 exacerbated bone mineral loss in the lumbar spine and femur whereas AD-FA lowered lean body mass in the hip compared to AD-CON(P < 0.05). Only AD-FAB12 exacerbated memory impairment by 1.3 and 1.4 folds, respectively, as measured by passive avoidance and water maze tests, compared to AD-CON(P < 0.01). Hippocampal insulin signaling and neuroinflammation were attenuated in AD-CON compared to Non-AD-CON. AD-FAB12 impaired the signaling (pAkt→pGSK-3β) and serum TNF-α and IL-1β levels the most among all groups. AD-CON decreased glucose tolerance by increasing insulin resistance compared to Non-AD-CON. AD-VB12 and AD-FAB12 increased insulin resistance by 1.2 and 1.3 folds, respectively, compared to the AD-CON. AD-CON and Non-AD-CON had a separate communities of gut microbiota. The relative counts of Bacteroidia were lower and those of Clostridia were higher in AD-CON than Non-AD-CON. AD-FA, but not V-B12, separated the gut microbiome community compared to AD-CON and AD-VB12(P = 0.009). In conclusion, folate and B-12 deficiencies impaired memory function by impairing hippocampal insulin signaling and gut microbiota in AD rats.

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