The Potential of Taro (Colocasia Esculenta) as a Dietary Prebiotic Source for the Prevention of Colorectal Cancer

Abstract

Taro (Colocasia esculenta) is a high dietary fiber tuber that holds great cultural and agricultural importance in the Pacific. Dietary fiber is the portion of food that is indigestible by the human gastrointestinal tract. Some dietary fibers are prebiotics since they can promote the growth of probiotic bacteria in the gut and their production of healthful short-chain fatty acids (SCFA). Maintaining a homeostatic gut microbiota through dietary modifications with the inclusion of high fiber foods has been shown to reduce the risk of colorectal cancer (CRC). CRC development is highly influenced by diet, with high fiber diets showing preventative properties. Thus, consumption of taro could potentially promote healthy gut microbiota and SCFA production and reduce CRC risk.This dissertation aimed to investigate the potential of taro as a prebiotic and explore its preventative characteristics against CRC through biochemical and epidemiological means. Through the biochemical methodology, five taro varieties were analyzed for the following objectives: 1) Determine the nutrient, physicochemical, and functional properties of taro varieties; 2) Determine the prebiotic fiber contents of taro varieties and their prebiotic activity scores after they were digested and absorbed in vitro; and 3) Understand the microbial changes that occur in the gut microbiome due to the presence of taro via in vitro fecal fermentation. Through the epidemiological methodology, the inclusion of taro as a high dietary fiber source was explored for the following objectives: 4) Determine the influence of taro on the risk of CRC through the analysis of the Multi Ethnic Cohort (MEC) Study and 5) Determine the association of dietary patterns, that include taro and taro products in the food groups, with CRC risk, using the MEC data. The outcomes of this dissertation contribute to increased knowledge of the biochemical and epidemiological aspects of taro’s beneficial properties for CRC prevention. Evidence of the nutrient composition and dietary prebiotic properties of taro, and its association with the activity of gut microbiota and the risk of CRC may help formulate effective prevention strategies for CRC.