scholarly journals SAT-657 The Gut Microbiome Regulates Host Glucose Homeostasis via Peripheral Serotonin

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Damien Keating

Abstract The gut microbiome is an established regulator of aspects of host metabolism, such as glucose handling. Despite the known impacts of the gut microbiota on host glucose homeostasis, the underlying mechanisms are unknown. The gut microbiome is also a potent mediator of gut-derived serotonin synthesis, and this peripheral source of serotonin is itself a regulator of glucose homeostasis. Here, we determined whether the gut microbiome influences glucose homeostasis through effects on gut-derived serotonin. Using both pharmacological inhibition and genetic deletion of gut-derived serotonin synthesis, we find [1] that the improvements in host glucose handling caused by antibiotic-induced changes in microbiota composition are dependent on the synthesis of peripheral serotonin. [1] The gut microbiome regulates host glucose homeostasis via peripheral serotonin. Proc Natl Acad Sci U S A. 2019 Oct 1;116(40):19802-19804. Martin AM, Yabut JM, Choo JM, Page AJ, Sun EW, Jessup CF, Wesselingh SL, Khan WI, Rogers GB, Steinberg GR, Keating DJ.

2019 ◽  
Vol 116 (40) ◽  
pp. 19802-19804 ◽  
Author(s):  
Alyce M. Martin ◽  
Julian M. Yabut ◽  
Jocelyn M. Choo ◽  
Amanda J. Page ◽  
Emily W. Sun ◽  
...  

The gut microbiome is an established regulator of aspects of host metabolism, such as glucose handling. Despite the known impacts of the gut microbiota on host glucose homeostasis, the underlying mechanisms are unknown. The gut microbiome is also a potent mediator of gut-derived serotonin synthesis, and this peripheral source of serotonin is itself a regulator of glucose homeostasis. Here, we determined whether the gut microbiome influences glucose homeostasis through effects on gut-derived serotonin. Using both pharmacological inhibition and genetic deletion of gut-derived serotonin synthesis, we find that the improvements in host glucose handling caused by antibiotic-induced changes in microbiota composition are dependent on the synthesis of peripheral serotonin.


2020 ◽  
Vol 79 (OCE2) ◽  
Author(s):  
Jessica C. Ralston ◽  
Kathleen A.J. Mitchelson ◽  
Gina M. Lynch ◽  
Tam T.T. Tran ◽  
Conall R. Strain ◽  
...  

AbstractReduced inflammatory signaling (IL-1RI-/-) alters metabolic responses to dietary challenges (1). Inflammasome deficiency (e.g. IL-18-/-, Asc-/-) can modify gut microbiota concomitant with hepatosteatosis; an effect that was transferable to wild-type (WT) mice by co-housing (2). Taken together, this evidence suggests that links between diet, microbiota and IL-1RI-signaling can influence metabolic health. Our aim was to determine whether IL-1RI-mediated signaling interacted with the gut microbiome to impact metabolic tissue functionality in a diet-specific fashion. Male WT (C57BL/J6) and IL-1RI-/- mice were fed either high-fat diet (HFD; 45% kcal) or low-fat diet (LFD; 10% kcal) for 24 weeks and were housed i) separately by genotype or ii) with genotypes co-housed together (i.e. isolated vs shared microbial environment; n = 8–10 mice per group). Glucose tolerance and insulin secretion response (1.5 g/kg i.p.), gut microbiota composition and caecal short-chain fatty acids (SCFA) were assessed. Liver and adipose tissue were harvested and examined for triacylglycerol (TAG) formation, cholesterol and metabolic markers (Fasn, Cpt1α, Pparg, Scd1, Dgat1/2), using histology, gas-chromatography and RT-PCR, respectively. Statistical analysis included 1-way or 2-way ANOVA, where appropriate, with Bonferroni post-hoc correction. Co-housing significantly affected gut microbiota composition, illustrated by clustering in PCoA (unweighted UniFrac distance) of co-housed mice but not their single-housed counterparts, on both HFD and LFD. The taxa driving these differences were primarily from Lachnospiraceae and Ruminococcaceae families. Single-housed WT had lower hepatic weight, TAG, cholesterol levels and Fasn despite HFD, an effect lost in their co-housed counterparts, who aligned more to IL-1RI-/- hepatic lipid status. Hepatic Cpt1α was lowest in co-housed WT. Adipose from IL-1RI-/- groups on HFD displayed increased adipocyte size and reduced adipocyte number compared to WT groups, but greater lipogenic potential (Pparg, Scd1, Dgat2) alongside a blunted IL-6 response to pro-inflammatory stimuli (~32%, P = 0.025). Whilst caecal SCFA concentrations were not different between groups, single-housed IL-1RI-/- adipocytes showed greatest sensitivity to SCFA-induced lipogenesis. Interestingly, differences in tissue functionality and gut microbiome occurred despite unaltered glucose tolerance; although there was a trend for phenotypic transfer of body weight via co-housing. For all endpoints examined, similar genotype/co-housing effects were observed for both HFD and LFD with the greatest impacts seen in HFD-fed mice. In conclusion, while the gut microbiome may be an important consideration in dietary interventions, these results question the magnitude of its impact in relation to the IL-1RI-dependent immunometabolism-glucose homeostasis axis.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rafael Corrêa ◽  
Igor de Oliveira Santos ◽  
Heloísa Antoniella Braz-de-Melo ◽  
Lívia Pimentel de Sant’Ana ◽  
Raquel das Neves Almeida ◽  
...  

AbstractGut microbiota composition can modulate neuroendocrine function, inflammation, and cellular and immunological responses against different pathogens, including viruses. Zika virus (ZIKV) can infect adult immunocompetent individuals and trigger brain damage and antiviral responses. However, it is not known whether ZIKV infection could impact the gut microbiome from adult immunocompetent mice. Here, we investigated modifications induced by ZIKV infection in the gut microbiome of immunocompetent C57BL/6J mice. Adult C57BL/6J mice were infected with ZIKV and the gut microbiota composition was analyzed by next-generation sequencing of the V4 hypervariable region present in the bacterial 16S rDNA gene. Our data showed that ZIKV infection triggered a significant decrease in the bacteria belonging to Actinobacteria and Firmicutes phyla, and increased Deferribacteres and Spirochaetes phyla components compared to uninfected mice. Interestingly, ZIKV infection triggered a significant increase in the abundance of bacteria from the Spirochaetaceae family in the gut microbiota. Lastly, we demonstrated that modulation of microbiota induced by ZIKV infection may lead to intestinal epithelium damage and intense leukocyte recruitment to the intestinal mucosa. Taken together, our data demonstrate that ZIKV infection can impact the gut microbiota composition and colon tissue homeostasis in adult immunocompetent mice.


2021 ◽  
Vol 9 (6) ◽  
pp. 1302
Author(s):  
Patrice D. Cani ◽  
Emilie Moens de Hase ◽  
Matthias Van Hul

The field of the gut microbiota is still a relatively young science area, yet many studies have already highlighted the translational potential of microbiome research in the context of human health and disease. However, like in many new fields, discoveries are occurring at a fast pace and have provided new hope for the development of novel clinical applications in many different medical conditions, not in the least in metabolic disorders. This rapid progress has left the field vulnerable to premature claims, misconceptions and criticism, both from within and outside the sector. Tackling these issues requires a broad collaborative effort within the research field and is only possible by acknowledging the difficulties and challenges that are faced and that are currently hindering clinical implementation. These issues include: the primarily descriptive nature of evidence, methodological concerns, disagreements in analysis techniques, lack of causality, and a rather limited molecular-based understanding of underlying mechanisms. In this review, we discuss various studies and models that helped identifying the microbiota as an attractive tool or target for developing various translational applications. We also discuss some of the limitations and try to clarify some common misconceptions that are still prevalent in the field.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Gabrielle L. Davidson ◽  
Niamh Wiley ◽  
Amy C. Cooke ◽  
Crystal N. Johnson ◽  
Fiona Fouhy ◽  
...  

AbstractThe microbial community in the gut is influenced by environmental factors, especially diet, which can moderate host behaviour through the microbiome-gut-brain axis. However, the ecological relevance of microbiome-mediated behavioural plasticity in wild animals is unknown. We presented wild-caught great tits (Parus major) with a problem-solving task and showed that performance was weakly associated with variation in the gut microbiome. We then manipulated the gut microbiome by feeding birds one of two diets that differed in their relative levels of fat, protein and fibre content: an insect diet (low content), or a seed diet (high content). Microbial communities were less diverse among individuals given the insect compared to those on the seed diet. Individuals were less likely to problem-solve after being given the insect diet, and the same microbiota metrics that were altered as a consequence of diet were also those that correlated with variation in problem solving performance. Although the effect on problem-solving behaviour could have been caused by motivational or nutritional differences between our treatments, our results nevertheless raise the possibility that dietary induced changes in the gut microbiota could be an important mechanism underlying individual behavioural plasticity in wild populations.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S896-S897
Author(s):  
Faris S Alnezary ◽  
Tasnuva Rashid ◽  
Khurshida Begum ◽  
Travis J Carlson ◽  
Anne J Gonzales-Luna ◽  
...  

Abstract Background Antimicrobials disrupt the gut microbiota by reducing gut microbiome diversity and quantity. Galleria mellonella provides an invertebrate model that is inexpensive, easy to maintain, and does not require specialized equipment. This study investigated the feasibility of using G. mellonella as an in vivo model to evaluate the effect of different antimicrobials on gut microbiota. Methods To determine baseline gut microbiota composition, the gut contents of G. mellonella were extracted and genomic DNA underwent shotgun meta-genomic sequencing. To determine the effect of infection and antibiotic use, 30 larvae were injected (left proleg) with ~1 × 105 colony-forming unit (cfu) of methicillin-resistant Staphylococcus aureus (MRSA) and were randomized 1:1:1 to treatment with vancomycin (20 mg/kg) or a natural antimicrobial (Nigella sativa seed oil, 70 mg/kg; NS oil), or a combination. The larvae were kept at 37°C post-infection and monitored daily for 72 hours for activity, extent of cocoon formation/growth, melanization, and survival. Two larvae from each group were randomly selected and homogenized with PBS as controls. After 24 hours of incubation, gut contents were extracted and plated for MRSA and Enterococcus cfu counts. Results Metagenomics analysis showed the gut microbiota composition of G. mellonella larvae was dominated by a subset of closely-related Enterococcus species. After 24 hours of exposure, mean Enterococcus counts were 4 × 103 cfu in the vancomycin arm and 6.2 × 104 cfu in the NS oil arm. Mean MRSA counts were 3.3 × 105 cfu in vancomycin arm and 1.5 × 104 cfu in NS oil arm. The combination of vancomycin and NS oil had higher Enterococcus counts than the vancomycin alone arm (6.3 × 104 cfu vs. 4 × 103 cfu, respectively), suggesting that NS oil may have a role in protecting the gut microbiota. Conclusion This study provides preliminary evidence to support the potential use of G. mellonella to assess the in vivo effect of a natural and synthetic antimicrobial on the gut microbiota. Disclosures All authors: No reported disclosures.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Lucille Yanckello ◽  
Jared Hoffman ◽  
Ishita Parikh ◽  
Jessie Hoffman ◽  
Stefan Green ◽  
...  

Abstract Objectives The APOE4 allele is a genetic risk factor for certain diseases, due in part to alterations in lipid and glucose metabolism. The gut microbiota is also known to impact metabolic and can be beneficially modulated by prebiotics. Prebiotics are fermented into metabolites by the gut microbiota. These metabolites act as gut-brain axis components. However, the interaction of the APOE4 allele, gut microbiota, and prebiotics are unknown. The goal of the study was to use prebiotic diet to restore the gut microbiome of mice with human APOE4 (E4FAD) genes. We hypothesized that the microbial compositions of E4 mice fed inulin, compared to control fed, will correlate to metabolites being produced by the microbiome that confer benefit to host metabolism. Methods At 3 months of age the E4FAD mice were fed for 4 months with either control or inulin diet. We used 16S rRNA sequencing to determine gut microbiota diversity and species variations; non-targeted UPLC-MS/MS and GC-MS analysis was used to determine metabolic profiles of blood. Results The inulin fed mice showed a more beneficial microbial taxa profile than those mice that were control fed. Control mice showed higher levels of dimethylglycine, choline, creatine and the polyamine spermine. Higher levels of spermine, specifically, correlate to higher levels of the Proteobacteria which has been implicated in GI disorders. E4 inulin fed mice showed higher levels of bile acids, short chain fatty acids and metabolites involved in energy, increased levels of tryptophan metabolites and robust increases in sphingomyelins. Specifically in E4 inulin fed mice we saw increases in certain genera of bacteria, all of which have been implicated in being beneficial to the composition of the microbiome and producing one or more of the above mentioned metabolites. Conclusions We believe the disparities of microbial metabolite production between E4 inulin fed mice and E4 control fed mice can be attributed to differences in certain taxa that produce these metabolites, and that higher levels of these taxa are due to the dietary intervention of inulin. Despite the APOE4 allele increasing one's risk for certain diseases, we believe that beneficially modulating the gut microbiota may be one way to enhance host metabolism and decrease disease risk over time. Funding Sources NIH/NIDDK T323048107792, NIH/NIA R01AG054459, NIEHS/NIH P42ES007380. Supporting Tables, Images and/or Graphs


2020 ◽  
Vol 70 (1) ◽  
Author(s):  
Yinlong Cheng ◽  
Yining Li ◽  
Yonghong Xiong ◽  
Yixin Zou ◽  
Siyu Chen ◽  
...  

Abstract Purpose To investigate the effect of liver-specific knockdown of ANGPTL8 on the structure of the gut microbiota. Methods We constructed mice with liver-specific ANGPTL8 knockdown by using an adeno-associated virus serotype 8 (AAV8) system harbouring an ANGPTL8 shRNA. We analysed the structure and function of the gut microbiome through pyrosequencing and KEGG (Kyoto Encyclopedia of Genes and Genomes) functional prediction. Results Compared with controls, ANGPTL8 shRNA reduced the Simpson index and Shannon index (p < 0.01) of the gut microbiota in mice. At the phylum level, the sh-ANGPTL8 group showed a healthier gut microbiota composition than controls (Bacteroidetes: controls 67.52%, sh-ANGPTL8 80.75%; Firmicutes: controls 10.96%, sh-ANGPTL8 8.58%; Proteobacteria: controls 9.29%, sh-ANGPTL8 0.98%; F/B ratio: controls 0.16, sh-ANGPTL8 0.11). PCoA and UPGMA analysis revealed a significant difference in microbiota composition, while KEGG analysis revealed a significant difference in microbiota function between controls and the sh-ANGPTL8 group. Conclusion Our results revealed that inhibition of ANGPTL8 signalling altered the structure of the gut microbiome, which might further affect the metabolism of mice. We have thus identified ANGPTL8 as a novel hepatogenic hormone potentially involving the liver-gut axis and regulating the structure of the gut microbiota.


Genes ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 748 ◽  
Author(s):  
Jin-Young Lee ◽  
Mohamed Mannaa ◽  
Yunkyung Kim ◽  
Jehun Kim ◽  
Geun-Tae Kim ◽  
...  

The aim of this study was to investigate differences between the gut microbiota composition in patients with rheumatoid arthritis (RA) and those with osteoarthritis (OA). Stool samples from nine RA patients and nine OA patients were collected, and DNA was extracted. The gut microbiome was assessed using 16S rRNA gene amplicon sequencing. The structures and differences in the gut microbiome between RA and OA were analyzed. The analysis of diversity revealed no differences in the complexity of samples. The RA group had a lower Bacteroidetes: Firmicutes ratio than did the OA group. Lactobacilli and Prevotella, particularly Prevotella copri, were more abundant in the RA than in the OA group, although these differences were not statistically significant. The relative abundance of Bacteroides and Bifidobacterium was lower in the RA group. At the species level, the abundance of certain bacterial species was significantly lower in the RA group, such as Fusicatenibacter saccharivorans, Dialister invisus, Clostridium leptum, Ruthenibacterium lactatiformans, Anaerotruncus colihominis, Bacteroides faecichinchillae, Harryflintia acetispora, Bacteroides acidifaciens, and Christensenella minuta. The microbial properties of the gut differed between RA and OA patients, and the RA dysbiosis revealed results similar to those of other autoimmune diseases, suggesting that a specific gut microbiota pattern is related to autoimmunity.


2018 ◽  
Vol 178 (1) ◽  
pp. 43-56 ◽  
Author(s):  
Yan Guo ◽  
Zhi-Ping Huang ◽  
Chao-Qian Liu ◽  
Lin Qi ◽  
Yuan Sheng ◽  
...  

Objective Bariatric surgery is recommended for patients with obesity and type 2 diabetes. Recent evidence suggested a strong connection between gut microbiota and bariatric surgery. Design Systematic review. Methods The PubMed and OVID EMBASE were used, and articles concerning bariatric surgery and gut microbiota were screened. The main outcome measures were alterations of gut microbiota after bariatric surgery and correlations between gut microbiota and host metabolism. We applied the system of evidence level to evaluate the alteration of microbiota. Modulation of short-chain fatty acid and gut genetic content was also investigated. Results Totally 12 animal experiments and 9 clinical studies were included. Based on strong evidence, 4 phyla (Bacteroidetes, Fusobacteria, Verrucomicrobia and Proteobacteria) increased after surgery; within the phylum Firmicutes, Lactobacillales and Enterococcus increased; and within the phylum Proteobacteria, Gammaproteobacteria, Enterobacteriales Enterobacteriaceae and several genera and species increased. Decreased microbial groups were Firmicutes, Clostridiales, Clostridiaceae, Blautia and Dorea. However, the change in microbial diversity is still under debate. Faecalibacterium prausnitzii, Lactobacillus and Coprococcus comes are implicated in many of the outcomes, including body composition and glucose homeostasis. Conclusions There is strong evidence to support a considerable alteration of the gut microbiome after bariatric surgery. Deeper investigations are required to confirm the mechanisms that link the gut microbiome and metabolic alterations in human metabolism.


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