Progress 10/02/14 to 09/30/19
Outputs
Target Audience:For this project, my graduate student, Matthew Warren, presented the results of our project at 2 scientific conferences, 1) Minorities in Agriculture and Related Sciences and 2) the Comparative Nutrition Society, and Matthew defended his MS thesis with the Department of Biological Sciences. We also had 6 undergraduates who participated in data collection. We are currently completing a manuscript that we will submit to the Journal of Nutrition. Thus, my target audience has been my students and the scientific community. Changes/Problems:The primary change is that we planned to collect milk samples from swine to characterize the swine milk microbiome, but we were unable to collect these samples. Specifically, we planned to collect samples from swine maintained as part of another ongoing investigation. Due to the illness of our colleague that lead the swine project, the research project was delayed and we were unable to collect the samples. Our funding was insufficient to support this sample collection without piggybacking on an ongoing study. Instead, we focused on improving the quantity of the main experimental study. What opportunities for training and professional development has the project provided?Funding for this project provided me with the opportunity to support a MS student who successfully defended his thesis and who has gone on to work on a PhD at NCSU. It also provided me with the opportunity to trian 6 undergraduates in animal husbandry and milk collection. How have the results been disseminated to communities of interest?The findings of this study has been presented at 2 scientific meetings and manuscript based on this work is currently being finalized for publication. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Due to unforseen illness of one of our co-PI's, Bartol, we were unable to evaluate the milk microbiome of swine, as we had originally planned. Instead we put all of our effort into completeing and strengthening our primary objective - evaluating the impact of a mothers diet on gut and milk microbial diversity. The following abstract describe the key findings of our study: Microorganisms in milk have traditionally been assumed to be contaminants, but recent data suggest that these microbial communities naturally reside in milk and may contribute to vital maternal effects. Investigators have speculated that microorganisms are derived, at least in part, from populations of microorganisms found in a mother's gut. Milk microorganisms are ingested by offspring gut and contribute to the microbial populations that colonize the offspring gut. Thus, factors that impact the population of microorganisms in milk have implications for advancing knowledge of how mothers influence offspring development. In this case, females are likely preparing offspring for a similar dietary environment at independence. To characterize the relationship between milk microbial diversity and maternal protein intake, a pilot study was conducted to characterize impact of maternal protein intake on gut microbial diversity in rats. Based on this preliminary analysis, diets with 10% and 20% protein were selected to determine impact of protein intake on milk microbial diversity. Milk was collected from Sprague-Dawley rat dams at 14 days post-partum. No differences were observed for dry matter or crude protein content of milk between treatment groups. Alpha diversity of milk microbiota from high protein fed rats was greater than low protein fed rats. Staphylococcus spp. taxa relative abundance was higher in LP milk samples compared to HP samples and Lactobacillus spp. taxa had higher relative abundance in HP milk samples compared to LP samples. The results of this investigation indicates that dietary protein intake affects gastrointestinal microbial diversity and suggests that protein content of a mother's diet impacts relative abundance of milk microorganisms. This study highlights the importance of dietary protein intake on composition of rat fecal and milk microbiota, with higher protein intake favoring potentially beneficial Lactobacillus populations in milk and reducing the relative abundance of potential pathogens like Staphylococcus taxa. Proteus mirabilis and Enterococcus faecalis were cultured from rat milk and are likely natural occurring bacteria found in rat milk. Future work with milk microorganisms involves examining possible interactions between beneficial bacteria like Lactobacillus and potential pathogenic bacteria like Staphylococcus to examine how maternal diet can affect offspring development.
Publications
- Type:
Theses/Dissertations
Status:
Accepted
Year Published:
2016
Citation:
Effects of dietary protein intake on fecal and milk microbiota
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Conference Proceedings: Effects of dietary protein intake on fecal and milk microbiota
- Type:
Journal Articles
Status:
Other
Year Published:
2017
Citation:
Near submission:
Journal article: Effects of dietary protein intake on fecal and milk microbiota
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Progress 10/01/17 to 09/30/18
Outputs
Target Audience:The target audience is the scientific community. This paper will be submitted to the Journal of Nutrition this semester. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Final training in manuscriptsubmission for the student whocompleted much of the work for this project will occur this year. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?We will work on themanuscript for publication. In addition, we will work to develop a new hatch project for submission by September.
Impacts
What was accomplished under these goals?
We are in the process of finalizing our manuscript for publication.
Publications
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Progress 10/01/16 to 09/30/17
Outputs
Target Audience:The target audience is the scientific community. This data was presented at the Comparative Nutrition Society meeting and will be submitted for publication to the Journal of Nutrition. Warren, M, M Liles, WR Hood. Effects of dietary protein intake on fecal and milk microbiota. Proceedings of the Comparative Nutrition Society 2016 Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The project allowed for the training of an MS student, who completed his thesis in 2016 and 6 undergraduate student that help with the project. How have the results been disseminated to communities of interest?We just received additional microbial analyses in Oct 2017 and completed the statistics over break. We should be ready to submit for publication in Febuary. What do you plan to do during the next reporting period to accomplish the goals?We'll get that paper finished up and submitted and complete and necessary revisions.
Impacts
What was accomplished under these goals?
Goal 1) Does maternal diet modulate the milk microbiome? We found significant effects of a mothers protein intake on the microbial content in her feces and cecum. Specifically, if a female rat consumed a high protein diet (20% protein), her GI tract had relatively lower species richness (alpha diversity) than females that consumed a high protein diet. Interestingly, this effect did not persist when the diversity of microbes were evaluated in milk. In milk, if a mother consumed a higher protein diet, she also produced milk that had greater microbial diversity. The most abundant microbial genera found in the milk of females consuming both diets was Rothia, and an important runner-up for both diets was Agrobacterium. In females that consumed a low protein diet, Staphylococcus and Streptococcus were also important, whereas Lactobacillus was important in the milk of mothers consuming a high protein diet. Bifidobacterium, Streptococcus, and Staphylococcus were previously implicated as being transferred from a mothers gut to her mammary gland via and entero-mammary pathway. If this were true, then one would anticipate that they would have a similar pattern of realtively abundance in the mothers GI and her milk. This was true for Bifidobacterium, which was higher in the cecum and milk of mothers consuming a low protein diet, but the relative abundance of this microbe in maternal feces and milk was <1%. Both Staphylococcus and Streptococcus were abundant in milk but essentially non-existent in the GI of mothers. Thus, if the entero-mammary mechanism occurs, it is likely unimportant for growth and development. Only 3 of 23 genera identified in the maternal cecum and milk display a similar pattern of variation between the low and high protein diets. Thus, gut microbes are unlikely to play an important role in milk microbial diversity. Females that consume high protein diet have been shown to produce higher protein milk. Variation the composition of milk within the gland is likely to impact the microbes that reside there. Goal 2) Effect of milk on offspring intestinal colonization? Greater microbial diversity has been correlated with improved health outcomes in many studies. In this study, pups suckling the milk with higher microbial diversity also had much higher growth rates. These differences cannot be uncoupled from the likely higher protein content of the milk produced by mothers consuming a high protein diet. There were few similarities between abundant microbes in a mothers milk and the pups cecum. Thus, if milk microbes play an important in establishing the microbes in a pups GI track, it is short-lived and does not persist until peak lactation. Application to the feeding and rearing practices for dairy and beef cattle and swine: Completing this study was incredibly valuable, is it questioned the importance of the proposal entero-mammary pathway of microbial transfer. This pathway is still considered likely in the literature, but as we deduced in discussions with immunologist - it is highly unlikely.
Publications
- Type:
Journal Articles
Status:
Other
Year Published:
2018
Citation:
Year published is an estimate. The manuscript will be submitted next month.
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Progress 10/01/15 to 09/30/16
Outputs
Target Audience:Students and the scientific community Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Funding for this project provided the opportunity to train a MS student who successfully defended his thesis and has gone on to work on a PhD at NCSU. Six undergraduates were trained in animal husbandry and milk collection. How have the results been disseminated to communities of interest?The findings of this study have been presented at two scientific meetings and a manuscript based on this work is currently being finalized for publications. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Due to unforseen illness of one of our co-PI's, Bartol, we were unable to evaluate the milk microbiome of swine, as we had originally planned. Instead we put all of our effort into completeing and strengthening our primary objective - evaluating the impact of a mothers diet on gut and milk microbial diversity. The following abstract describe the key findings of our study: Microorganisms in milk have traditionally been assumed to be contaminants, but recent data suggest that these microbial communities naturally reside in milk and may contribute to vital maternal effects. Investigators have speculated that microorganisms are derived, at least in part, from populations of microorganisms found in a mother's gut. Milk microorganisms are ingested by offspring gut and contribute to the microbial populations that colonize the offspring gut. Thus, factors that impact the population of microorganisms in milk have implications for advancing knowledge of how mothers influence offspring development. In this case, females are likely preparing offspring for a similar dietary environment at independence. To characterize the relationship between milk microbial diversity and maternal protein intake, a pilot study was conducted to characterize impact of maternal protein intake on gut microbial diversity in rats. Based on this preliminary analysis, diets with 10% and 20% protein were selected to determine impact of protein intake on milk microbial diversity. Milk was collected from Sprague-Dawley rat dams at 14 days post-partum. No differences were observed for dry matter or crude protein content of milk between treatment groups. Alpha diversity of milk microbiota from high protein fed rats was greater than low protein fed rats. Staphylococcus spp. taxa relative abundance was higher in LP milk samples compared to HP samples and Lactobacillus spp. taxa had higher relative abundance in HP milk samples compared to LP samples. The results of this investigation indicates that dietary protein intake affects gastrointestinal microbial diversity and suggests that protein content of a mother's diet impacts relative abundance of milk microorganisms. This study highlights the importance of dietary protein intake on composition of rat fecal and milk microbiota, with higher protein intake favoring potentially beneficial Lactobacillus populations in milk and reducing the relative abundance of potential pathogens like Staphylococcus taxa. Proteus mirabilis and Enterococcus faecalis were cultured from rat milk and are likely natural occurring bacteria found in rat milk. Future work with milk microorganisms involves examining possible interactions between beneficial bacteria like Lactobacillus and potential pathogenic bacteria like Staphylococcus to examine how maternal diet can affect offspring development.
Publications
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2016
Citation:
Effects of dietary protein intake on fecal and milk microbiota
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Conference Proceedings: Effects of dietary protein intake on fecal and milk microbiota
|
Progress 10/02/14 to 09/30/15
Outputs
Target Audience:During this reporting period, we collected data and my graduate student presented results at scientific conference,Minorities in Agriculture and Related Sciences. Thus, my target audience was my students and the scientific community. Changes/Problems:In the original project we had also proposed to collect data from swine as a follow up to the rat study. However, because our budget was cut in half and our colloraborator who has experience in swine lactation has been ill, we have been unable to complete that part of the project. What opportunities for training and professional development has the project provided?One gradaute student and 6 undergraduates were training on this project. The graduate student will finshing his MS this coming summer. How have the results been disseminated to communities of interest?Data on fecal microbial diversity was presented at the Minorites in Agriculture and Related Sciences meeting in 2015. What do you plan to do during the next reporting period to accomplish the goals?In the next year, we plan to complete the milk analysis. The graduate student will complete his thesis. We expect to submit our results for publication this summer and submit 2 papers for publication.
Impacts
What was accomplished under these goals?
We have conducted the animal experiments and collected both fecal and milk samples from the rats. We have analyzed microbial diversity in the feces of females on a low (LP, 10%), medium (MP, 15%) and high protein (HP, 20%) diets and our analysis on milk microbial diversity is still pending. Females consuming the LP protein diet had a greater presence of Actinobacteria in their feces compared to rats that consumed MP or HP diets. There was little difference in relative abundance of Actinobacteria in fecal microbiota of rats consuming MP and HP diet and relative abundance of Actinobacteria for both diets was less than 1%. Rats consuming LP diets had a higher percentage of Bacteroidetes present in their feces compared to rats consuming MP or HP diet which provides similar results to what Zhou et al. (2016) seen with pigs with pigs consuming LP diet had higher abundance of Prevotella, in Bacteroidetes phylum. A diet with more protein and fat compared to carbohydrates can contribute to a higher relative abundance of Bacteroidetes (De Filippo et al., 2010). Firmicutes, one of the most dominant phyla in gut microbiota, is associated with carbohydrates and obesity (Ley et al., 2006). Rats consuming LP diet showed a decrease in Firmicutes in their fecal microbiota; however, LP diet is higher in carbohydrates, which means there may some metabolic pathways being utilized by Bacteroidetes that may be inhibiting growth of Firmicutes. Rats consuming the HP diet had highest relative abundance of Firmicutes and it may be associated with short-chain fatty acids (SCFA) which are produced from indigestible carbohydrates because it has been shown that a diet high in proteins can also be associated with microorganisms that produce SCFAs (Liu et al., 2014). Gut microbial diversity is well associated with how healthy a gut is. We observed that rats consuming LP diet had a higher observed operational taxonomic unit (OTU) count in their fecal microbiota than rats consuming the HP diet. Higher OTU counts means there is more unique microorganisms found in a sample and it also correlates to microbial diversity in a microbiota. We also calculated Shannon-Wiener's (H`) Index values for each dietary treatment to see if species richness and diversity is related to diet. LP rats had the highest H` value, but was statistically significant when compared to HP rats. Rats consuming MP or LP had similar H` values and it can be ascertained that high protein intake (like 20% diet from the HP diet) can be seen as an imbalance to gut health and may have similar effects to gut microbiota like a highcarbohydrate or high-fat diet.
Publications
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