Honors Theses
Date of Award
2015
Document Type
Undergraduate Thesis
Department
Biology
First Advisor
Colin Jackson
Relational Format
Dissertation/Thesis
Abstract
The human gut contains a highly diverse set of bacteria that perform a wide range of duties that include much more than just nutrient acquisition. However, the composition of this community is subject to change, with diet, age and lifestyle playing roles in the development and maintenance of the gut microbiota. This study compared the bacterial composition of the human gut when consuming a normal diet versus a dairy-free diet. Samples were taken from a single subject during three periods: 1) control (normal) diet, 2) dairy-free diet, and 3) a return to normal diet. Gut bacterial communities were identified and compared using 16S rRNA gene sequencing. Relative to the total number of sequences within a sample, abundances were calculated for dominant bacterial groups starting at the phylum level and progressing to the smallest identifiable taxonomic group. Fluctuations were seen at taxonomic levels from class down to species. Non-metric multidimensional scaling ordination revealed that the samples from each dietary period were distinguishable from the other periods. Six significant operational taxonomic units (OTUs), from three phyla, were significantly related to dietary sample distributions. These OTUs consisted of two members of the Bacteroidetes (both genus Bacteroides), three from Firmicutes (genus Megasphaera, genus Acidamniococcus, and Butyricicoccus pullicaecorum), and one from Actinobacteria (Collinsella aerofaciens). This study shows that alterations to a diet can cause changes of the relative abundances of bacteria in the human gut at multiple taxonomic levels, but that at the level of the entire community these shifts in gut microbiota can be reversed.
Recommended Citation
Stovall, Patrick Tyler, "Not Got Milk? The Effect on the Gut Microbiome of Removing Dairy from the Diet" (2015). Honors Theses. 751.
https://egrove.olemiss.edu/hon_thesis/751
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