Coffee and metabolites modulating the gut microbiome for improved colorectal cancer survival - PROJECT SUMMARY / ABSTRACT
More than 1.5 million Americans are currently living with colorectal cancer (CRC). Improving CRC survivorship
is a high priority. Diet is an important factor influencing CRC prognosis. The use of dietary modification to
supplement conventional cancer therapy is an eminently practical approach. Growing data indicate the anti-
cancer benefit of coffee consumption. In the US, 64% of adults drink coffee daily, with an average consumption
of 2.7 cups per day. Coffee contains hundreds of antioxidants and other bioactive compounds, which are
degraded and modified by the gut microbiota and endogenous enzymes to generate secondary metabolites.
These metabolites may protect against CRC by reduction of inflammation, modulation of metabolism, and
inhibition of tumor growth and invasion. In particular, compelling data indicate the benefit of coffee for reducing
risk of fatty liver and liver fibrosis, conditions that have been linked to worse survival of CRC, possibly by
promotion of liver metastasis, the major cause of CRC death. Recently, we showed in four independent
prospective cohorts that CRC patients consuming 4 cups/d or more of coffee had a 40-50% lower risk of
recurrence and CRC-specific death compared with nondrinkers. However, the causality and specific
mechanisms for this relationship remain unknown. To address this knowledge gap, we propose to conduct a
biomarker-based randomized placebo-controlled trial and assess the prognostic influence of the interplay
between coffee intake and the metabolomic and microbial signatures in patients with stage III CRC. We
hypothesize that compounds in coffee and their metabolites improve CRC survival by modulating the gut
microbiome and ameliorating liver fatness and fibrosis. In Aim 1, we will determine the effect of coffee
consumption on the gut microbiome and metabolome, liver fatness and fibrosis, and markers of CRC recurrence
in a randomized controlled trial of freeze-dried instant coffee and placebos for 3 months among 80 stage III
colon cancer patients who have completed chemotherapy. In Aim 2, we will prospectively assess coffee intake,
fecal microbial features and metabolites in relation to CRC recurrence and survival in a cohort of 450 stage III
CRC patients who provide detailed dietary data and stool specimens. Our ability to accomplish these aims is
underscored by our experience with dietary intervention and biobanking studies in CRC; our multi’omic profiling
effort to elucidate the interplay between diet, the gut microbiome, and host metabolism in CRC; as well as our
experienced multidisciplinary team comprised of experts in nutrition, microbiome, epidemiology, oncology, and
hepatology. The mechanistic insights provided by the project will not only help refine the recommendations for
cancer survivorship for one of the most commonly consumed beverages worldwide, but also lead to discovery
of novel adjuvant therapeutics and development of novel interventions based on manipulation of the diet,
metabolome, and microbiome for improved CRC management.