For most people ecology is something external appreciated during road trips or hikes. But for Cancer Center at Illinois (CCIL) member Christopher Gaulke and his research team the most intriguing ecosystem exists within us. Each of us hosts trillions of microorganisms as part of our body’s microbiome. While microbes inhabit many areas of the body Gaulke’s focus is on the gut microbiome due to its significant role in diseases particularly gastrointestinal cancers.

Gaulke’s research on HIV-microbiome interactions ignited a deeper curiosity about the microbiome’s broader role in supporting human health. While he had a strong foundation in ecology microbiology and molecular biology he recognized a gap in his expertise bioinformatics. To bridge this he pursued a postdoctoral position in microbiome analysis under the mentorship of bioinformatician and biostatistician Thomas Sharpton at Oregon State University where he could strengthen his skills in uncovering the mechanisms behind host-microbiome interactions.

The gut microbiome offers two major avenues for understanding gastrointestinal cancers: as a predictive screening tool and as a potential therapeutic agent for individuals at higher risk. To explore its role in early detection Gaulke partnered with Oregon Health and Science University (OHSU) to compare the microbiomes of patients with pre-cancerous polyps to those without.

In this study we aimed to find out whether microbiome changes seen in the later stages of colorectal cancer were also present in its early precancerous stages Gaulke explained. What we discovered was quite unexpected patients with colonic adenomas which are benign tumors that can progress to cancer if left untreated had significantly different microbial profiles compared to those without adenomas. Remarkably some of the same microbial taxa disrupted in advanced cancer were already altered at this early stage.

Beyond its role in early detection Gaulke and his collaborators at OHSU are also exploring therapeutic strategies for individuals showing microbial indicators of disease. Diet plays a central role in shaping the gut microbiome and is a major risk factor for colorectal cancer. Gaulke noted that individuals with microbiomes linked to polyp formation often consumed lower amounts of fruits grains and vegetables. Their microbiomes also showed reduced levels of genes responsible for producing beneficial short-chain fatty acids compounds that come from fiber-rich foods like those mentioned and others high in soluble fiber.

We now have a cohort where we’re testing whether we can shift the microbiome toward a healthier profile using fiber alone Gaulke explained. If that proves successful, it opens the possibility of using fiber therapeutically in individuals with precancerous adenomas to lower their risk of progressing to colorectal cancer.

Source: https://cancer.illinois.edu/exploring-the-ecosystems-inside-of-us-the-microbiome-and-colorectal-cancer/