The association between the implementation of a 6-month fiber-rich diet and the presence of metabolomic markers that are linked to colon cancer risk. Restricted; Files Only

Kohn, Jordyn (Spring 2023)

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Diet is a known modifiable factor that can either have negative or positive implications for the incidence of colorectal cancer, a cancer that has affects roughly 1 in 23 men and 1 in 26 women28. There are many aspects of a diet that can lead to outcomes of interest, in this case, metabolomic markers that are linked to colorectal cancer risk.


Fiber is what we investigated within a study population of 15 people, both males (n=8) and females (n=7), as well as Black (n=7), White (n=7), and Hispanic (n=1) individuals using a subset of data from an ongoing randomized controlled clinical trial. By comparing variables of interest at each participants’ baseline and 6-month visits.

This randomized clinical feeding trial is being conducted to gain an understanding of the implications a specific diet has on weight-related variables and gastrointestinal (GI) tract transit times, among other things. Data was collected from each participant at baseline and 6 months, standardized as needed, and compared using both a Wilcoxon Signed Rank Test and a Spearman’s Correlation Tests.


Overall, results did not provide sufficient evidence to support the hypothesis that an increased fiber intake (g/ 1,000 kilocalories) is associated with a decrease in weight, BMI, waist circumference, and total percent body fat and a decrease in GI tract transit time variables. When stratifying on sex, we saw that the associations among men were more robust for changes in weight, waist circumference and total percent body fat (p-values < 0.05), than those observed within females.


What this study provides is a basis of knowledge that can be expanded upon. Other macronutrients can be compared to these outcome variables over a longer period. A larger sample size will also prove to be beneficial in producing more robust findings. There is a need for more research surrounding these topics. A broader scope of knowledge can be achieved and eventually be shared within the cancer research community, potentially leading to a decreased burden of colorectal cancer in the United States.

Table of Contents

Table of Contents

Chapter 1: Literature Review.. 1

How Diet Affects Health. 1

High Fiber Diet and Health. 1

High Fiber Diet and Obesity. 2

High Fiber Diet and Cancer 3

Diet and the Gut Microbiome/Metabolic Health. 4

Gut Metabolome Markers. 5

Chapter 2: Materials and Methods. 7

Introduction. 7

Methods. 9

Participants. 9

Recruitment 9

Entrees. 10

Randomization. 10

Measurement of Variables. 10

Analysis. 12

Results. 13

Discussion. 21

Chapter 3: Public Health Implications. 24

References. 25

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