Project description:Microbial functions in the host physiology are a result of co-evolution between microbial communities and their hosts. Here we show that cold exposure leads to marked shift of the microbiota composition, referred to as cold microbiota. Transplantation of the cold microbiota to germ-free mice is sufficient to increase the insulin sensitivity of the host, and enable complete tolerance to cold partly by promoting the white fat browning, leading to increased energy expenditure and fat loss. During prolonged cold however, the body weight loss is attenuated, caused by adaptive mechanisms maximising caloric uptake and increasing intestinal, villi and microvilli lengths. This increased absorptive surface is promoted by the cold microbiota - effect that can be diminished by co-transplanting the most downregulated bacterial strain from the Verrucomicrobia phylum, Akkermansia muciniphila, during the cold microbiota transfer. Our results demonstrate the microbiota as a key factor orchestrating the overall energy homeostasis during increased demand.
Project description:Microbial functions in the host physiology are a result of co-evolution between microbial communities and their hosts. Here we show that cold exposure leads to marked shift of the microbiota composition, referred to as cold microbiota. Transplantation of the cold microbiota to germ-free mice is sufficient to increase the insulin sensitivity of the host, and enable complete tolerance to cold partly by promoting the white fat browning, leading to increased energy expenditure and fat loss. During prolonged cold however, the body weight loss is attenuated, caused by adaptive mechanisms maximising caloric uptake and increasing intestinal, villi and microvilli lengths. This increased absorptive surface is promoted by the cold microbiota - effect that can be diminished by co-transplanting the most downregulated bacterial strain from the Verrucomicrobia phylum, Akkermansia muciniphila, during the cold microbiota transfer. Our results demonstrate the microbiota as a key factor orchestrating the overall energy homeostasis during increased demand.
Project description:<p>Emerging evidence that the gut microbiota may contribute in important ways to human health and disease has led us and others to hypothesize that both symbiotic and pathological relationships between gut microbes and their host may be key contributors to obesity and the metabolic complications of obesity. Our "Thrifty Microbiome Hypothesis" poses that gut microbiota play a key role in human energy homeostasis. Specifically, constituents of the gut microbial community may introduce a survival advantage to its host in times of nutrient scarcity, promoting positive energy balance by increasing efficiency of nutrient absorption and improving metabolic efficiency and energy storage. However, in the presence of excess nutrients, fat accretion and obesity may result, and in genetically predisposed individuals, increased fat mass may result in preferential abdominal obesity, ectopic fat deposition (liver, muscle), and metabolic complications of obesity (insulin resistance, hypertension, hyperlipidemia). Furthermore, in the presence of excess nutrients, a pathological transition of the gut microbial community may occur, causing leakage of bacterial products into the intestinal lymphatics and portal circulation, thereby inducing an inflammatory state, further aggravating metabolic syndrome traits and accelerating atherosclerosis. This pathological transition and the extent to which antimicrobial leakage occurs and causes inflammatory and other maladaptive sequelae of obesity may also be influenced by host factors, including genetics. In the proposed study, we will directly test the Thrifty Microbiome Hypothesis by performing detailed genomic and functional assessment of gut microbial communities in intensively phenotyped and genotyped human subjects before and after intentional manipulation of the gut microbiome. To address these hypotheses, five specific aims are proposed: (1) enroll three age- and sex-matched groups from the Old Order Amish: (i) 50 obese subjects (BMI > 30 kg/m2) with metabolic syndrome, (ii) 50 obese subjects (BMI > 30 kg/m2) without metabolic syndrome, and (iii) 50 non-obese subjects (BMI < 25 kg/m2) without metabolic syndrome and characterize the architecture of the gut microbiota from the subjects enrolled in this study by high-throughput sequencing of 16S rRNA genes; (2) characterize the gene content (metagenome) to assess the metabolic potential of the gut microbiota in 75 subjects to determine whether particular genes or pathways are correlated with disease phenotype; (3) characterize the transcriptome in 75 subjects to determine whether differences in gene expression in the gut microbiota are correlated with disease phenotype, (4) determine the effect of manipulation of the gut microbiota with antibiotics on energy homeostasis, inflammation markers, and metabolic syndrome traits in 50 obese subjects with metabolic syndrome and (5) study the relationship between gut microbiota and metabolic and cardiovascular disease traits, weight change, and host genomics in 1,000 Amish already characterized for these traits and in whom 500K Affymetrix SNP chips have already been completed. These studies will provide our deepest understanding to date of the role of gut microbes in terms of 'who's there?', 'what are they doing?', and 'how are they influencing host energy homeostasis, obesity and its metabolic complications? PUBLIC HEALTH RELEVANCE: This study aims to unravel the contribution of the bacteria that normally inhabit the human gastrointestinal tract to the development of obesity, and its more severe metabolic consequences including cardiovascular disease, insulin resistance and Type II diabetes. We will take a multidisciplinary approach to study changes in the structure and function of gut microbial communities in three sets of Old Order Amish patients from Lancaster, Pennsylvania: obese patients, obese patients with metabolic syndrome and non-obese individuals. The Old Order Amish are a genetically closed homogeneous Caucasian population of Central European ancestry ideal for genetic studies. These works have the potential to provide new mechanistic insights into the role of gut microflora in obesity and metabolic syndrome, a disease that is responsible for significant morbidity in the adult population, and may ultimately lead to novel approaches for prevention and treatment of this disorder.</p>
Project description:Insect gut microbiota plays important roles in acquiring nutrition, preventing pathogens infection, immune responses, and communicating with the environment. Gut microbiota can be affected by some external factors such as foods, temperature, and antibiotics. Spodoptera frugiperda (Lepidoptera: Noctuidae) is an important destructive pest of grain crops all over the world. The function of gut microbiota in S. frugiperda remains to be investigated. In this study, we fed the S. frugiperda with the antibiotic mixture (penicillin, gentamicin, rifampicin, and streptomycin) to perturb the gut microbiota, and further examined the effect of dysbiosis in gut microbiota on the gene expression of S. frugiperda by RNA sequencing. We found the composition and diversity of the gut bacterial community were changed in S. frugiperda after antibiotics treatmen, and the expression of genes related to energy and metabolic process were affected after antibiotics exposure in S. frugiperda. Our work will help understand the role of gut microbiota in insects.
Project description:The aim of this project was to explore the role of gut microbiota in the development of small intestine. The gut microbiota from different groups was used to treat the mice for 1 or 2 weeks. Then the small intestine samples were collected. The RNA was used for the RNA-seq analysis to search the role of gut microbiota in the development of small intestine. Groups: IMA100 mean gut microbiota from Alginate oligosaccharide 100mg/kg treated mice; IMA10 mean gut microbiota from Alginate oligosaccharide 10mg/kg treated mice; IMC mean gut microbiota from control group mice (dosed with water); Sa mean dosed with saline (no gut microbiota). "1" mean dosed for 1 week, "2" means dosed for 2 weeks.
Project description:Whether myogenesis is affected by the maternal gut dysbacteriosis still remains ambiguous. In this study, firstly we show elevated level of lipopolysaccharides (LPS) in a gut microbiota dysbiosis mouse model. Secondly, we demonstrate that the diameter of muscle fibres, limb development and somitogenesis were inhibited in both gut microbiota dysbiosis and LPS exposed mice and chicken embryos. These might be due to LPS disturbed the cell survival and the key genes which regulating the somitogenesis and myogenesis. RNA sequencing and subsequent validation experiments verified that retinoic acid (RA) signaling perturbation was mainly responsible for the aberrant somite formation and differentiation. Subsequently, we found that LPS-induced Roxidative stress (ROS generation and antioxidant genes such as Nrf2, AKR) contributed to the above-mentioned interference with RA signaling. These findings highlight that the gut microbiota homeostasis also involved in regulating the development of muscle progenitor cells during pregnancy.
Project description:Whether myogenesis is affected by the maternal gut dysbacteriosis still remains ambiguous. In this study, firstly we show elevated level of lipopolysaccharides (LPS) in a gut microbiota dysbiosis mouse model. Secondly, we demonstrate that the diameter of muscle fibres, limb development and somitogenesis were inhibited in both gut microbiota dysbiosis and LPS exposed mice and chicken embryos. These might be due to LPS disturbed the cell survival and the key genes which regulating the somitogenesis and myogenesis. RNA sequencing and subsequent validation experiments verified that retinoic acid (RA) signaling perturbation was mainly responsible for the aberrant somite formation and differentiation. Subsequently, we found that LPS-induced Roxidative stress (ROS generation and antioxidant genes such as Nrf2, AKR) contributed to the above-mentioned interference with RA signaling. These findings highlight that the gut microbiota homeostasis also involved in regulating the development of muscle progenitor cells during pregnancy.
Project description:Gut microbiota plays an important role during early development via bidirectional gut- brain signaling. We aimed to explore the potential link between gut microbiota/gut derived metabolites and sympathoadrenal stress responsivity