NEWS | October 28, 2014

Study on Western diet and role in GI cancer funded

UC Davis researchers also will study if friendly bacteria can prevent it

(SACRAMENTO, Calif.)

The National Cancer Institute (NCI) has awarded a $2.7 million grant to UC Davis researchers to investigate how the so-called Western diet, which is high in fat and sugar, increases the risk of developing liver and gastrointestinal (GI) cancers. In addition, the researchers will study whether bifidobacteria, a common family of bacteria in the human gut, can be enriched to prevent cancer.

Left to right: Carolyn Slupsky, Yu-Jui Yvonne Wan and David Mills Left to right: Carolyn Slupsky, Yu-Jui Yvonne Wan and David Mills

“We know that people who are obese or diabetic have increased risk for GI cancer,” said Yu-Jui Yvonne Wan, one of three principal investigators and vice chair for research in the Department of Pathology and Laboratory Medicine. “But we need to have a better understanding of how these conditions lead to cancer and how to prevent it.”

Other principal investigators on the study are Professors Carolyn Slupsky and David Mills, both in the Department of Food Science & Technology and members of the Foods for Health Institute.

The study’s first goal will be to understand how the Western diet affects metabolism, bile acid and friendly bacteria (microbiota). While researchers already have learned that diets high in fat and sugar generate toxic bile acid, which causes inflammation and damages DNA, the mechanisms of this process are poorly understood.

Perhaps most importantly, the researchers also will investigate whether specific bifidobacteria species can mitigate the Western diet’s negative effects. The team will test whether a combination of complex milk sugars and bifidobacteria can reduce inflammation and short-circuit the mechanisms that generate cancer.

“When we talk about gastrointestinal health, we have to think about microbiota,” said Wan. “We believe that enriching the gut with anti-inflammatory bifidobacteria can protect against GI cancer.”

Wan has been investigating the liver for more than three decades. For many years, she studied how retinoic acid (a metabolite of vitamin A) worked in the liver. This line of inquiry helped illuminate the relationship between retinoic acid and bile acids, both of which regulate fat metabolism. As her research progressed, it became apparent that the health of the liver and of the GI system, including the esophagus, pancreas, stomach and colon, are inextricably linked and that bile acid is a key factor.

“Bile acid is made in the liver and circulates to the gut and back,” noted Wan. “You cannot ignore the gut when you study the liver.”

Ultimately, the team hopes the research will provide a better understanding of how metabolic issues lead to cancer, as well as delivering a new strategy to prevent the disease.

The research is funded with NCI grant No. 1U01CA179582-01A1.

UC Davis Comprehensive Cancer Center
UC Davis Comprehensive Cancer Center is the only National Cancer Institute-designated center serving the Central Valley and inland Northern California, a region of more than 6 million people. Its specialists provide compassionate, comprehensive care for more than 10,000 adults and children every year, and access to more than 150 clinical trials at any given time. Its innovative research program engages more than 280 scientists at UC Davis, Lawrence Livermore National Laboratory and Jackson Laboratory (JAX West), whose scientific partnerships advance discovery of new tools to diagnose and treat cancer. Through the Cancer Care Network, UC Davis collaborates with a number of hospitals and clinical centers throughout the Central Valley and Northern California regions to offer the latest cancer care. Its community-based outreach and education programs address disparities in cancer outcomes across diverse populations. For more information, visit cancer.ucdavis.edu.