The Hidden Link Between Farming, Your Microbiome and Immunotherapy Success

In an interview with The Educated Patient, Nathan Goodyear, M.D., an integrative physician at the Williams Cancer Institute, explains why understanding cancer — and preventing it — requires looking at the whole picture, not just individual systems in the body. According to Goodyear, modern medicine often breaks things into smaller parts to analyze them but fails to put them back together in a way that reflects how the body truly functions. This narrow approach, he says, leads to repeated errors in how we view disease.

Goodyear argues that our health is deeply connected to the health of our environment, especially the soil where our food grows. Industrialized farming practices (heavy on pesticides, chemicals and a focus on yield over nutrient quality) have transformed living soil into “dead dirt.” That deadened soil produces nutrient-poor crops, which then shape a weakened gut microbiome. Because the gut microbiome plays a major role in immune function, he explains, this environmental chain ultimately influences cancer risk.

He points to research showing that cancer has become the leading cause of death in high-income countries, surpassing cardiovascular disease. Instead of waiting for cancer to develop and relying solely on early detection, Goodyear believes prevention needs to be a bigger focus — and that begins with restoring immune strength at the foundational level.

A major part of that foundation is the gut. He cites emerging data, including findings from the “baby biome” study, showing a concerning decline in important gut bacteria among infants — early evidence of how environmental changes ripple into human health across generations.

For patients already diagnosed with cancer, Goodyear emphasizes that these insights still matter. Simple, science-supported steps, such as increasing dietary fiber to 30 to 50 grams per day, can improve the effectiveness of immunotherapy treatments. Fiber feeds the gut microbiome, which in turn produces metabolites that enhance immune activity. This means everyday nutrition can meaningfully support modern cancer therapies.

Goodyear believes the path to better cancer prevention and better treatment outcomes begins with rethinking our relationship to the environment, strengthening the gut microbiome and viewing disease not as an isolated event but as the result of many interconnected systems. “We get what we sow,” he says — both in our soil and in our health.