Progress 01/01/16 to 02/28/19
Outputs
Target Audience:Over the lifetime of the award, we targeted diverse audiences in the field, including nutritional scientists, microbiologists, chemists, scientists in vascular biology and medical doctors. Seminars and reach out activities done in previous years are listed in previous reports. In the last year, we presented our work at Yale University (CT), The Hormel Institute (MN), University of Chicago (Il), Brown University, RI. Changes/Problems:The was a minor change of direction because we found in Aim 2 that choline metabolism did not affect atherosclerosis. However, we found that it impacts AD progression and glucose homeostasis. What opportunities for training and professional development has the project provided?The project provided training opportunities for 2 graduate students: Kym Romano (completed PhD 2017), and Katie Zarbock (joined the lab summer of 2018). How have the results been disseminated to communities of interest?Over the three years of training, this work has been presented at more than 20 scientific seminars worldwide (including scientific meetings and seminar at universities) and in local outreach events in the state of Wisconsin. What do you plan to do during the next reporting period to accomplish the goals?As mentioned above, we continue to explore the role of gut microbial metabolism of choline and TMAO accumulation on diabetes and Alzheimers disease.
Impacts
What was accomplished under these goals?
Accomplishmet during the whole funding cycle: Aim 1. By using diverse microbial communities that were first assayed in vitro and then transplanted into germ-free mice we demonstrated that complex native communities of gut microbes exhibit a large degree of variation on their ability to metabolize choline and generate TMA(O). We demonstrated this by transplanting multiple fecal samples from humans into groups of germ-free mice (Romano 2018). We also found that gut bacteria efficiently compete with the host for dietary choline, significantly lowering its bioavailability as well as plasma and hepatic levels of metabolites involved in one-carbon metabolism (Romano 2015, 2017). Microbial-induced depletion of methyl donors is associated with altered DNA methylation patterns in adult mice and their offspring (Romano 2017). Furthermore, mice harboring high levels of choline consuming bacteria showed altered hepatic and adipose gene expression, and increased susceptibility to diet-induced metabolic disease. Altogether, our results suggest that the gut microbiome's capacity to metabolize choline should be considered when making recommendations about dietary choline intake in different stages of development. Aim 2. We tested the role of choline-derived TMAO in the development of atherosclerosis, and found that intestinal colonization with high levels of choline-consuming bacteria results in high levels of TMAO, but it does not exacerbate atherosclerosis in ApoE -/- mice, relative to genetically identical animals colonized with communities of bacteria that do not metabolize choline/produce TMAO. However, we found that it alters glucose homeostasis. We collaborated with the Biddinger group at Harvard to dissect how bacterial derived TMAO affects glucose homeostasis by increasing insulin resistance via FoxO1 signaling (Manuscript published in Cell Metabolism). Additionally, we have discovered an association between TMAO and biomarkers of Alzheimer's disease (Vogt et al 2018), which we are investigating further. Our preliminary results have revealed that TMAO alters activation of astrocytes in the brain (currently in progress).
Publications
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Progress 10/01/17 to 09/30/18
Outputs
Target Audience:We primarily targeted other researchers in this field including nutritional scientists, microbiologists, chemists, scientists in vascular biology and medical doctors. A seminar on this work was given at Wisconsin Medical College (Milwukee, WI), Experimental Biology Annual Meeting (San Diego, CA), American Society of Gastroenterology Annual Meeting Washington, DC), and Universidad Nacional de Cordoba (Argentina). It taleked about this work at "The Larry Meiller Show" (Wisconsin Public Radio). I participated in a program (Bacteriology) where we explained in general terms the importance of gut microbes to human health, nutrition and this work and listeners called with questions. Additionally, I discussed this work at UW Lobby day 2018 in Washington DC. In this event I discussed with members of congress the importance of federally funded research and discussed the implications of our findings with the Hatch grant. Changes/Problems:Since we did not find a major effect of choline metabolism on atherosclerosis, we will be focusing on Alzheimer's disease and diabetes, where we have seen promising results. What opportunities for training and professional development has the project provided?Two graduate students (Kym Romano, graduated at the end of 2017) and Katie Karbock (Joined the lab summer of 2018) have benefited from this grant. How have the results been disseminated to communities of interest?Yes. Seminars discussing this work were given at Wisconsin Medical College (Milwukee, WI), Experimental Biology Annual Meeting (San Diego, CA), American Society of Gastroenterology Annual Meeting (Washington, DC), and Universidad Nacional de Cordoba (Argentina). What do you plan to do during the next reporting period to accomplish the goals?We will continue to examine the role of choline metaboilsm on Alzheimer's disease and diabetes.
Impacts
What was accomplished under these goals?
Aim 1. We followed-up on our discoveries from published on 2017 and demonstrated that complex native communities of gut microbes exhibit a large degree of variation on their ability to metabolize choline. We demonstrated this by transplanting multiple fecal samples from humans into groups of germ-free mice (Romano 2018). Aim 2. We tested the role of choline-derived TMAO in the development of atherosclerosis, and found that intestinal colonization with high levels of choline-consuming bacteria results in high levels of TMAO, but it does not exacerbate atherosclerosis, relative to mice colonized with communities of bacteria that do not metabolize choline/produce TMAO. However, we found that it alters glucose homeostasis. We collaborated with the Biddinger group at Harvard to dissect how bacterial derived TMAO affects glucose homeostasis by increasing insuling resistance via FoxO1 signaling (manuscript under review at science). Additionally, we have discovered an association between TMAO and biomarkers of Alzheimer's disease, which we are investigating further.
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2018
Citation:
Fecal Aliquot Straw Technique (FAST) allows for easy and reproducible subsampling: assessing interpersonal variation in trimethylamine-N-oxide (TMAO) accumulation.Microbiome.2018;6:91. doi: 10.1186/s40168-018-0458-8
- Type:
Journal Articles
Status:
Under Review
Year Published:
2019
Citation:
The gut microbe-dependent metabolite trimethylamine N-oxide promotes glucose intolerance by activating a PERK-FoxO1 axis. Sifan Chen, Mary Gearing, Michael Petriello, Kymberleigh A. Romano, Ayana Henderson1, Ji Miao, Jiahui Tao, Bingdong Sha4, Mark Graham, Rosanne Crooke, Federico E. Rey, Andrew Morris, Sudha B. Biddinger. Under review at Science.
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Progress 10/01/16 to 09/30/17
Outputs
Target Audience:We primarily targeted other researchers in this field including nutritional scientists, microbiologists, chemists, scientists in vascular biology and medical doctors. A seminar on this work was given at the Food Research Institute (UW-Madison & University of Chicago joined meeting), University of California-Los Angeles, Icahn School of Medicine, Mount Sinai, International meetings in Colombia and Germany. Outreach talks were given at FermentationFest (Sauk County, WI) and for the PEOPLE program (audience was 8th graders going into high school). Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?A graduate student (Kym Romano) and a visiting PhD student from Universidad de la Sabana (Colombia) were trained in this project. How have the results been disseminated to communities of interest?Kym Romano presented her work at the 2017 general meeting of the American Heart Association and at the Cleveland Clinic. What do you plan to do during the next reporting period to accomplish the goals?We will focus on the aspects related to choline consumption and atherosclerosis related to Aim2.
Impacts
What was accomplished under these goals?
While making progress in aim 1, we found a large degree of variability in choline consumption and TMAO accumulation among old adults in vivo and in vitro (n=11) that TMAO levels are inversely associated with choline bioavailability (R2 = 0.5945; P-value = 0.0003). In year 1, while making progress in aim 2, we made an important discovery that changed slighly the focus of the project: we discovered that gut bacteria efficiently compete with the host for free choline, significantly lowering both its bioavailability, as well as, plasma and hepatic levels of downstream methyl-donor metabolites. Bacterial-induced depletion of methyl-donor availability is associated with altered DNA methylation patterns in adult mice and their offspring. Furthermore, mice harboring high levels of choline consuming bacteria show altered gene expression in hepatic and adipose tissues and increased susceptibility to diet-induced metabolic disease. Altogether, our results suggest that the gut microbiome's capacity to metabolize choline should be considered when making recommendations about dietary choline intake in different stages of development.
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2017
Citation:
Romano KA, Martinez-del Campo A, Kasahara K, Chittim CL, Vivas EI, Amador-Noguez D, Balskus EP, Rey FE. 2017. Metabolic, Epigenetic, and Transgenerational Effects of Gut Bacterial Choline Consumption. Cell Host Microbe 22(3):279-290
- Type:
Journal Articles
Status:
Submitted
Year Published:
2018
Citation:
Romano KA, Dill-McFarland1 KA, Kasahara K, Kerby R, Vivas EI, Amador-Noguez D, Herd P, Rey FE. Fecal Aliquot Straw Technique (FAST) allows for easy and reproducible sub-sampling: Assessing interpersonal variation in trimethylamine-N-oxide (TMAO) accumulation. Sumbitted to Microbiome Journal October 2017
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Progress 01/01/16 to 09/30/16
Outputs
Target Audience:We primarily targeted other researchers in this field including nutritional scientists, microbiologists, chemists, scientists in vascular biology and medical doctors. Seminar on this work were given at the Food Research Institute (UW-Madison), Cleveland Clinic, National Academy of Sciences. Outreach talks were given for diybio (a community of do-it-yourself biotech innovators, tinkerers, and scientifically-minded citizens who generate and act on ideas that solve real world problems in the life sciences) and for the PEOPLE program (audience was 8th graders going into high school). We think that new concepts arising from this work will benefit all segments of society. Efforts: During the last year one undergraduate and one graduate student performed research in our laboratory related to this project. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?A graduate student (Kym Romano) and a summer undergraduate researcher (Lacey Lopez) worked on this project. Kym Romano presented her work at the 2017 General meeting of the American Heart Association How have the results been disseminated to communities of interest?Results were presented at the American Heart Association General meeting (November 2016, New Orleans). We are also writing a manuscript that we plan to submit to Cell Host Microbe by the Spring of 2017. What do you plan to do during the next reporting period to accomplish the goals?We will continue transplanting fecal communities into germ-free mice (aim 2) and will focus our work on the cardiovascular aspects.
Impacts
What was accomplished under these goals?
We made significant progress towards both aims, including an unexpected discovery that we are very excited about and will soon submit for publication. Please see below: Aim 1:Assess interpersonal variation in gut microbial conversion of choline to TMA among elderly adults. Task-Perform in vitro assays of TMA production from choline and fecal microbiota characterization from fecal samples collected from lean healthy subjects, obese subjects, diabetic subjects, and subjects with coronary disease (n=60) Accomplished: We assayed in vitro 30 human fecal samples to assess choline consumption/TMA production. We found a wide range of responses among these samples; i.e., whereas microbes present in some fecal samples subjects are very efficient at using choline as a growth substrate, other samples do not show as much activity. We will complete the next 30 during 2017. Aim 2:Test the role of microbiota-choline interactions in the development of atherosclerosis. Task- Perform fecal microbiota transplantation of selected samples tested in aim 1 (n=5) into germ-free apoE-/- mice and assess the development of atherosclerosis. Using information from Aim 1 we chose five samples for follow-up transplant experiments in wild-type germ-free mice. We observed that when mice are colonized with fecal samples that consume high levels of choline, mice exhibit higher levels of TMAO and lower choline in their plasma. Transplants into ApoE mice will be done in the second stage. Exciting discovery: We found that gut bacteria efficiently compete with the host for dietary choline, significantly lowering its bioavailability as well as plasma and hepatic levels of metabolites involved in one-carbon metabolism. Microbial-induced depletion of methyl donors is associated with altered DNA methylation patterns in adult mice and their offspring. Furthermore, mice harboring high levels of choline consuming bacteria showed altered hepatic and adipose gene expression, and increased susceptibility to diet-induced metabolic disease. Altogether, our results suggest that the gut microbiome's capacity to metabolize choline should be considered when making recommendations about dietary choline intake in different stages of development.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Oral presentation at the American Heart Association General Meeting; Proceedings of the meeting were published in the Journal Circulation.
Gut Microbial Utilization of Choline Significantly Alters Host Lipid, DNA Methylation, and Hepatic Gene Expression Profiles. Kymberleigh A Romano, Ana Martinez del Campo, Kimberly A Krautkramer, Kazuyuki Kasahara, Eugenio I Vivas, John M Denu, Daniel Amador-Noguez, Emily P Balskus, Federico E Rey
Publication date 2016/11/11
Journal Circulation
Volume 134
Suppl 1
Pages A19174-A19174
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