Progress 02/01/14 to 01/31/17
Outputs
Target Audience:Research scientists, educators, and professionals in nutrition and food science Food industry: producers and processors of fruits and vegetables. Blueberry industry representatives Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Two graduate students in Nutritional Sciences (1 MS and 1 PhD in progress) and two graduate students (1 MS and 1 PhD in progress) in Food Science completed research projects. Two additional graduate students and one undergraduate student in Food Science and Nutritional Sciences trained in and contributed to research methodology for this project. How have the results been disseminated to communities of interest? Lee SH, Kirkland, R, Fischer JG, de La Serre CB. Dietary blueberry supplementation improves glucose tolerance in high-fat diet-fed rats: a role for the microbiota? Georgia Nutrition Council Annual Conference, Pine Mountain, GA, February, 2016. Conference for food and nutrition professionals in school nutrition programs, cooperative extension, dietetics in addition to research scientists in food science and nutrition. de La Serre, CB. Using the microbiota to fight obesity? Centers for Disease Control and Prevention / University of Georgia collaborative meeting, March 2016. Lee SH, Kirkland R, Fischer JG, de La Serre CB. Blueberry supplementation impacts gut microbiota, inflammatory profiles and insulin sensitivity in high-fat fed rats. Presented at the Experimental biology Annual Meeting, San Diego, CA, April 2016, Meeting for nutrition research scientists, students and industry professionals. Keirsey KI, Lee SH, de La Serre CB, Fischer JG. Blueberry supplementation alters biomarkers of oxidative stress in high-fat fed rats. Presented at the Experimental Biology Annual Meeting, San Diego, CA, April 2016. Poster selected for student competition. Meeting for nutrition research scientists, students and industry professionals. Fischer, J. presented "Impact of a High Anthocyanin Food on Intestinal Microbiota and Intestinal and Systemic Inflammation," at the USDA/NIFA Institute of Food Safety and Nutrition 2016 Function and Efficacy of Nutrients, Improved Processing Technologies, and Improving Food Quality Project Directors' meeting, San Diego, CA, April 6, 2016 SH Lee, R Kirkland, JG Fischer, CB de La Serre. Dietary blueberry supplementation improves glucose tolerance in high-fat diet-fed rats: a role for the microbiota? Society for the Study of Ingestive Behavior, Porto, Portugal, 2016 and SH Lee presentation at Alltech's Young Scientist Competition, Lexington, KY, 2016 Fischer JG Healthy Diets:Bioactives in Fruits and Vegetables. Georgia Organics Conference, Atlanta, GA, February, 2017. Meeting for producers and consumers interested in organic food production. de La Serre CB. Manipulating the gut microbiota composition to alleviate obesity. Food Sciences and Technology Department seminar series, University of Georgia, March 2017. Koh J, Xu Z, Wicker L. Extraction methods influence physicochemical properties of blueberry pectin that impact anthocyanin binding. IFT17 Annual Meeting and Food Expo. Las Vegas, Accepted for presentation June 25-28, 2017. Meeting of food science researchers and industry professionals. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Our research enhances knowledge of how high intakes of fruits such as berries can improve human health. More specifically, our study increases understanding of how blueberry, a high anthocyanin fruit, impacts intestinal microflora, systemic inflammation and insulin resistance in an animal model of obesity. We showed that blueberry consumption resulted in a significant shift in intestinal microflora along with decreases in intestinal and systemic inflammation and improvement in glucose tolerance in high-fat fed rodents. In addition, we examined blueberry components that may impact the fruit's health-promoting properties. We characterized blueberry pectins for the first time and also demonstrated binding between pectins and anthocyanins which may impact distribution and action of these bioactive components within the intestinal tract. Overall, this research furthers our understanding of the health benefits of blueberry and provides data for the informed use of pectin and anthocyanins as food ingredients and the development of functional foods. Objectives 1 and 2 were to examine the effect of blueberry on gastrointesinal microbiota and inflammation in high-fat fed, obese rodents. Rats were fed diets that were low-fat, high-fat or high fat supplemented with 10% whole freeze dried blueberry for 8 weeks. Diets were matched for fiber and sugar content. We assessed the impact of blueberry on gut microbiota and biomarkers of inflammation, oxidative stress and intestinal integrity. Food intake and body weight were assessed. An oral glucose tolerance test was conducted and markers of insulin resistance were determined. High fat feeding increased visceral and liver fat as expected in all high fat-fed rats, and blueberry did not reduce adiposity or liver fat. Final body weight did not differ among groups. Intestinal (cecal) microbiota composition was assessed using Illumina MiSeq high throughput sequencing. Abundance analysis at all taxonomic levels showed that high fat feeding alone did not result in major changes in gut microbiota compared to low fat feeding except for a decrease in Rumminococcus (Firmicutes, Clostridia, Clostridiales, Ruminococcaceae) in high fat-fed animals. This data supports recent reports showing that deleterious effects of high fat feeding on microbiota composition can be diminish by fibers. However, blueberry supplementation led to significant changes in gut microbiota with decreases in both Firmicutes and Bacteriodetes abundance and increases in Fusobacteria and Proteobacteria abundance, compared to both low-fat fed and high-fat fed rats. The increase in Proteobacteria was associated with a significant increase in the Gammaproteobacteria class, especially the Pasteurellales order, including the genus Actinobacillus and Aggregatibacter. Although there was an overall decrease in Firmicutes, blueberry supplementation led to increased abundance of Bacilli (Class), especially Lactobacillales (Order). Serum levels of short chain fatty acids (SCFA), which reflect gut bacterial fermentation, were assessed with gas chromatography-mass spectrometry. Increases in serum acetate were found in blueberry supplemented rats compared to non-supplemented rats. Serum proprionate was higher and butyrate was lower in blueberry supplemented rats compared to low fat fed rats. These changes could result from changes in gut microbiota or from the fermentable carbohydrates in blueberry. Gene expression of markers of intestinal, adipose tissue and liver inflammation was assessed with real-time quantitative PCR. High fat feeding was associated with an increase in ileal Tnfa gene expression, a marker of inflammation, but this was normalized by blueberry. Blueberry reduced high-fat diet-induced increases in both Tnfa and IL-1b gene expression in visceral adipose tissue. Lipopolysaccharide (LPS) binding protein was used as a marker of circulating LPS, a component of the outer-membrane of gram negative bacteria which promotes systemic inflammation. High fat feeding produced a non-significant increase in circulating LBP compared to low fat-fed rats, but blueberry led to a significant reduction in circulating LBP when compared to the high fat-fed rats. Markers of oxidative stress were also assessed. In the liver, high-fat fed rats had increased lipid peroxidation which returned to normal with blueberry supplementation. In contrast, a marker of systemic lipid peroxidation, urinary F2-isoprostanes was increased in blueberry supplemented rats. Inflammation associated with obesity and visceral adiposity has been associated with insulin resistance. Blueberry supplementation improved glucose tolerance in high fat-fed rats. This was shown by a reduction in peak glycemia compared to non-supplemented rats, and while high-fat feeding significantly elevated serum insulin, blueberry returned this to levels found in low-fat fed rats. Further, a marker of impaired insulin signaling, hepatic p-IRS1 (Ser307), which is upregulated by inflammation, was assessed. While high-fat feeding increased hepatic p-IRS-1 (Ser307)/IRS1 ratio, it was normalized with blueberry supplementation. We also assessed ileal glucagon-like peptide-1 (GLP-1) which improves insulin secretion and sensitivity and is down regulated by high fat feeding. We similarly found a decrease in GLP-1 gene expression in high-fat fed rats that was restored to normal by blueberry supplementation. This may have resulted from changes seen in SCFA production which stimulate GLP-1 release. Blueberry-induced improvements in gastrointestinal integrity may have contributed to decreases in intestinal and systemic inflammation. High fat diets altered intestinal morphology, with decreases in villus length and in the number of goblet cells which secrete mucins, but these changes were returned to normal with blueberry addition. Blueberry also increased gene expression of mucin 2 in the ileum compared to levels found in high-fat fed rats and increased anti-bacterial peptide beta-defensin 2 gene expression compared to low-fat fed fats. These changes are both associated with improved gut integrity. Overall, this research demonstrated an antiinflammatory effect of blueberry in high-fat fed rodents associated with improved insulin sensitivity. These changes were found in conjunction with changes in gut microbiota composition and improvement of the intestinal epithelial barrier. Objective 3 was to extract and characterize pectic substances and other cell wall components from blueberry and to study the binding of blueberry anthocyanins to pectic substances. Studies showed that blueberry tends to be lower in pectin content compared to other fruits; blueberry pectin tends towards lower degree of esterification, even the water soluble pectin. The high charge on blueberry pectin likely accounts for the strong electrostatic binding of anthocyanins. Pectin and anthocyanin binding was documented; binding was most favorable at pH 2.0-3.6. Ionic interactions and anthocyanin stacking are likely the mechanism of pectin and anthocyanin binding. Cell wall glycan-directed monoclonal antibodies based glycome profiling analyses revealed that water soluble, chelator soluble and alkali soluble pectin fractions had epitopes of homogalacturonan, arabinogalactan, and xyloglucan, but no xylan. HPSEC-MALS-RI chromatography revealed both water and chelator soluble pectins were polydisperse and high molecular weight of around 450 kDa in the major eluting peaks, while alkali soluble pectin had lower molecular weight of 177 kDa. Under in vitro digestion conditions, pectins prevented anthocyanin degradation and the more highly charged chelator soluble pectin showed greater protection than water soluble pectin. The free anthocyanin content of blueberry juice mixed with chelator soluble pectin was nearly 5 times that of control or water soluble pectin added blueberry juice, after 3.5 hr of simulated, sequential gastric and intestinal conditions.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2017
Citation:
Koh J, Xu Z, Wicker L. 2017. Extraction methods influence physicochemical properties of blueberry pectin that impact anthocyanin binding. Accepted for IFT Annual Meeting and Food Expo. Las Vegas, NV, June, 2017. Finalist, Carbohydrate Division
- Type:
Journal Articles
Status:
Submitted
Year Published:
2017
Citation:
Lee SH, Keirsey KI, Kirkland R, Grunewald ZI, Fischer JG, de La Serre CB. Blueberry supplementation alters gut microbiota and improves inflammatory profile and insulin signaling in high fat fed rats. Submitted to Journal of Nutrition, 4/2017
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Lee, S.H., Kirkland, R., Fischer, J.G., & de La Serre, C.B. (2016). Blueberry supplementation impacts gut microbiota, inflammatory profiles, and insulin sensitivity in high-fat fed rats. FASEB J, 30, A692.25.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Keirsey, K.I., Lee, S.H., de La Serre, C.B., & Fischer, J.G. (2016). Blueberry supplementation alters biomarkers of oxidative stress in high-fat fed rats. FASEB J, 30, A1174.23.
- Type:
Theses/Dissertations
Status:
Other
Year Published:
2016
Citation:
Keirsey, KI. Blueberry supplementation alters markers of oxidative stress in high fat fed rats. Thesis, University of Georgia
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Progress 02/01/15 to 01/31/16
Outputs
Target Audience:Research scientists, educators and professionals in the areas of nutrition, food science and health. Food industry professionals with an interest in bioactive components of foods and functional foods. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Training opportunities were provided for two graduate students in the University of Georgia Department of Food Science and Technology under the supervision of Dr. Louise Wicker and for three graduate students in the University of Georgia Department of Foods and Nutrition under the supervision of Drs. Joan Fischer and Claire de La Serre. How have the results been disseminated to communities of interest?J. Fischer presented results at the USDA/NIFA - AFRI/NRI Function and Efficacy of Nutrients/Bioactive Components for Optimal Health, and Improving Food Quality Program Directors Meeting, Chicago, IL, July 10, 2015. SH Lee presented results at the FASEB Science Research Conference: Gastrointestinal Tract XVI: GI Homeostasis: The Microbiome and the Barrier, Development and Disease, Steamboat Springs, CO, August 2, 2015. Presentation authors and title: Lee SH, Kirkland R, Fischer J, de La Serre C. Dietary blueberry supplementation improves glucose tolerance in high-fat diet-fed rats: a role for the microbiota. What do you plan to do during the next reporting period to accomplish the goals?To continue progress for Objectives 1 and 2 we will assess gastrointestinal tissue morphology and conduct alcian blue mucin staining of ileal and colon tissue to further characterize changes in intestinal barrier function. In addition, tissue macrophage staining is still in progress to further assess antiinflammatory effects of blueberry. Urinary metabolomic analysis to identify bacterial products associated with blueberry consumption is planned. For Objective 3, we will continue studies examining anthocyanin-pectin binding under varying conditions. Results of these studies will be submitted for publication in scientific journals, included in theses and dissertations of graduate students, and presented in seminars and at national/international conferences.
Impacts
What was accomplished under these goals?
Objective 1 is to examine the effect of whole blueberry on gastrointestinal microflora composition, oxidative stress and inflammation in high-fat fed, obese rodents and Objective 2 is to examine the impact of whole blueberry on systemic inflammation and inflammatory markers of adipose tissue. One animal feeding trial was conducted with rats fed diets that were low fat, high fat and high fat with 10% freeze dried blueberry for 8 weeks. High fat and high-fat blueberry supplemented diets were isocaloric and matched for sugar and fiber content. Food intake was equal for rats fed high-fat and high fat-blueberry diets. Compared to the low fat diet, high fat feeding resulted in increased adiposity and liver fat deposition in both high-fat fed and high-fat blueberry fed rats. Measures of insulin resistance were conducted. Despite identical intake and body weight, blueberry supplementation improved glucose tolerance and insulin signaling in high-fat fed rats as shown by decreases in peak glucose and insulin responses. Blueberry supplementation also increased ileal glucagon-like-peptide-1(GLP-1) expression and downregulated liver pSer307IRS1/IRS1 ratio (Insulin receptor substrate 1), changes associated with improved glucose tolerance. To characterize intestinal microflora, analysis of microbial RNA was completed via Illumina sequencing (UC Davis Host Microbe Systems Biology Core). There were significant decreases in Firmicutes and Bacteroidetes and increases in Proteobacteria and Fusobacteria found in the high-fat fed blueberry supplemented rats compared to the low-fat fed and high-fat fed rats. Markers of gut barrier function have been measured and were improved with blueberry supplementation in high fat fed rats with decreases in serum lipopolysaccharide-binding protein (LBP) and increases in ileal gene expression of defensin and mucin 2. Ileal TNF-alpha gene expression, a marker of inflammation was also significantly decreased in blueberry supplemented rats. Further, markers of inflammation in serum, adipose tissue and liver were measured. Antiinflammatory effects of blueberry supplementation in high fat fed rats were suggested by decreased TNF-alpha and cluster of differentiation 11d (CD11d) gene expression in visceral fat and reduced TNF-alpha and interleukin-6 protein levels in liver. Measures of oxidative stress have also been assessed. Liver malondialdehyde, a marker of lipid peroxidation, was elevated by HF feeding but was significantly lower in blueberry supplemented high-fat fed animals. Unexpectedly, a significant increase in F2-isoprostanes, a marker of systemic lipid peroxidation was found with blueberry supplementation. Overall, analyses completed thus far suggest a potential anti-inflammatory effect of blueberry supplementation associated with improved glucose tolerance. For objective 3, studies on the binding of anthocyanins and pectin fractions were completed and further studies are in progress. It was found that compared to other pectins, blueberry pectin fractions were soluble in water, of higher molecular wt, near 450 kDa, and had a low degree of esterification of 26-39%, regardless of solvent solubility. Pectin-anthocyanin binding was demonstrated and was lowest at pH 4.5 and higher at pH 2-3.6. Ionic interaction between anthocyanin flavylium cations and free pectic carboxyl groups, and anthocyanin stacking may be two major mechanisms for pectin and anthocyanin binding. One publication has resulted from this work thus far.
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2016
Citation:
Lin, Z., Fischer, J., & Wicker, L. (in press). Intermolecular binding of blueberry pectin-rich fractions and anthocyanin. Food Chemistry, 194, 986-993. doi:10.1016/j.foodchem.2015.08.113
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Progress 02/01/14 to 01/31/15
Outputs
Target Audience: Research scientists, educators and graduate scientists in the area of food science and health through seminar presentations. Food industry professionals with an interest in bioactive components of foods and functional foods. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Training opportunities were provided for 4 graduate students in the University of Georgia Department of Food Science and Technology under the supervision of Dr. Louise Wicker and for 2 graduate students and 2 undergraduate students in the University of Georgia Department of Foods and Nutrition under the supervision of Drs. Joan Fischer and Claire de la Serre. J.Fischer attended the 2014 USDA/NIFA Function and Efficacy of Nutrients/Bioactive Components for Optimal Health, and Improving Food Quality Porgram Director's Meeting, San Diego, CA, April 26, 2014 . How have the results been disseminated to communities of interest? Two seminar presentations have introduced the research project and data to research scientists, educators and graduate students. Fischer, J.G. Impact of high anthocyanin food on intestinal microbiota and subsequent intestinal & systemic inflammation, University of Georgia (UGA) Obesity Initiative Food Ingredients Team, November 19, 2013. Lin, Z. Blueberry cell wall fractionation and intermolecular binding between pectin rich fractions and anthocyanins. Seminar Presentation, Department of Food Science and Technology, University of Georgia, June 4th, 2014. One conference presentation reached research scientists and food industry professionals with an interest in bioactive components of foods and functional foods. Wicker, L. 2014. UGA Obesity Initiative: Food industry and Academia Consortia. SE Institute of Food Technologists, April 14, 2014 What do you plan to do during the next reporting period to accomplish the goals? To continue progress as planned for Objectives 1 and 2 we will complete analysis of intestinal microflora abundance, intestinal oxidative stress and gene and protein expression of markers of inflammation in liver and adipose tissue. For objective 3, we will continue and complete studies examining anthocyanin-pectin binding under varying conditions. Results of these studies will be submitted for publication in scientific journals, included in theses and dissertations of graduate students and presented in seminars and national/international conferences.
Impacts
What was accomplished under these goals?
Objective 1 is to examine the effect of whole blueberry on gastrointestinal microflora composition, oxidative stress and inflammation in high-fat fed, obese rodents and Objective 2 is to examine the impact of whole blueberry on intestinal microflora composition and the relationships with systemic inflammation and inflammatory markers of adipose tissue in obese rodents. Work on both objectives is still in progress. One animal feeding trial has been conducted to address both objectives. Rats were fed low fat, high fat and high fat diets with 10% freeze-dried blueberry powder for 8 weeks. Body weight and food intake was monitored daily and food intake was managed to assure similar food intakes between the high-fat fed rats and high-fat blueberry fed rats. Measures of insulin resistance, including the oral glucose tolerance test (OGTT) and insulin tolerance test, were conducted. Circulating insulin levels were also determined during the OGTT. Urine was collected for F2-isoprostanes, a biomarker of oxidative stress, and analysis of these samples has been completed. At the time of euthanization, cecum contents, blood, liver, mesenteric and epididymal adipose tissue, and intestinal sections and mucosa were collected. Analysis of gut permeability using florescent dextran and serum biomarkers of microbiota-derived inflammation has been completed. Gene and protein expression of inflammatory factors such as TNF-alpha and IL-6 in liver, visceral fat and subcutaneous fat are in progress. Liver staining for fat accumulation has been completed. Analysis of samples to determine intestinal microflora abundance and assessment of intestinal oxidative stress are in progress. Objective 3 is to extract and characterize pectic substances and other cell wall components from blueberry and to determine if blueberry anthocyanins and pectin fractions form complexes that survive the gastrointestinal tract for colonic delivery. This work has application in the food industry and also is relevant to the understanding of the site of action of anthocyanins in the intestinal tract. The objective to extract and characterize pectic substances and other cell wall components from blueberry has been completed and work on binding of anthocyanins and pectin fractions is still in progress. Five cell wall fractions were extracted and characterized from blueberry powder, including three pectin rich fractions and two hemicellulose-rich fractions. Uronic acid concentration, protein and sugar content and degree of methylesterification were determined. Glycome profiling analysis was conducted to further characterize polysaccharide content. An examination of the potential for blueberry pectin-rich fractions to bind to anthocyanins, anthocyanidins and blueberry juice anthocyanins was conducted at varying pH. It was determined that blueberry pectin-rich fractions bind anthocyanins and binding is pH dependent.
Publications
- Type:
Journal Articles
Status:
Under Review
Year Published:
2015
Citation:
Lin,Z, Fischer, J., Wicker, L. Intermolecular binding between pectin rich fractions and anthocyanin. Food Chemistry, under review 2015.
- Type:
Journal Articles
Status:
Other
Year Published:
2015
Citation:
Lin,Z., Pattahil., S., Hahn, M.G., Wicker, L. Blueberry cell wall fractionation, characterization and glycome profiling. To be submitted to Carb. Polymers 2015.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2014
Citation:
Wicker, L. 2014. UGA Obesity Initiative: Food industry and Academia Consortia. SE Institute of Food Technologists, April 14, 2014
- Type:
Theses/Dissertations
Status:
Submitted
Year Published:
2014
Citation:
Lin, Z. Blueberry cell wall fractionation and intermolecular binding between pectin rich fractions and anthocyanins. Department of Food Science and Technology, University of Georgia
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