Fiber to Reduce Colon Cancer in Alaska Native People

Completed · Not applicable

Conditions studied: Colon Cancer

In brief

Alaska native people (AN) have the highest recorded incidence and death rate from colon cancer in the world (\>90:100,000). We hypothesize that the AN, despite their high consumption of anti-inflammatory and antineoplastic n-3 fish oils, are at increased risk of colon cancer because of colonic butyrate deficiency resulting from their remarkably low consumption of fiber-containing foods. We hypothesize that fiber supplementation of their usual diet will result in a bloom of butyrate producing microbes in the colon, resulting in increased butyrate production, which will suppress their high microbial secondary bile acid production, antagonize the actions of other food (smoked fish) and environmental carcinogens (tobacco, alcohol), and interact with the high circulating levels of n-3 fish oils to suppress colonic inflammation and cancer risk. In order to investigate this, we will conduct a randomized double-blinded 4-week clinical trial in up to 100 randomizable healthy, middle-aged AN undergoing screening colonoscopy, with the objective of obtaining 60 completed interventions. The interventions will consist of either a high-dose soluble fiber supplement given as a drink, together with their usual diet which currently contains about 15g total fiber/d, or to a control digestible starch drink plus their usual diet. The primary endpoint will be a clinically significant reduction in Ki67 proliferative colonic mucosal biomarkers of cancer risk. Microbiome and metabolome mechanisms responsible for the anticipated changes in mucosal biomarkers will also be investigated. Our results in extreme risk AN will be further evaluated by comparison to similar measurements previously made in minimal risk rural Africans and intermediate risk African Americans. Our results will be used to provide the scientific basis for a definitive large-scale high-fiber supplementation study (to achieve \>50g total fiber/d) to suppress adenomatous polyp recurrence following colonoscopy.

Key facts

Study ID
NCT03028831
Run by
University of Pittsburgh
People needed
48
Starts
2017-12-11
Expected to finish
2022-12-31
Last updated by the study team
2023-05-16

Who can join

Age: 40 and older, up to 70. Sex: any. Healthy volunteers: accepted.

Where it is running

Full record on ClinicalTrials.gov

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