A trend has arisen from college students discussing their “freshman 15,” addressing the weight that they gained during their first year of college as a result the food they consumed. Usually, their diet contains ultra processed foods such as donuts, cookies, and chips.
While it is known these foods do not fuel the body in a healthy way, the true effects go much deeper onto a microscopic level in the body. The body’s health relies partially on the gut microbiome, which can be disturbed by unhealthy eating habits.
“Your gut, inside your intestines, is in fact a miniature biome, populated by trillions of microscopic organisms,” explains the Cleveland Clinic staff on the Cleveland Clinic website.
These microorganisms inside of the gut play a critical role in digesting food and protecting the body from illnesses. A balance between these microorganisms allows the gut to function.
“In general, intake of diet rich in fruits, vegetables and fibers is associated with a higher richness in diversity of the gut microbiota,” says Sai Manada Jandhyala and his colleagues in a study published by the National Library of Medicine.
Switching to a diet that favors each of the nutrients fuels the gut and allows it to function properly. However, when proper nutrition is now followed, it can lead to a phenomenon referred to as dysbiosis.
The Cleveland Clinic website explains, “dysbiosis means: a loss or deficit of beneficial bacteria, overgrowth of potentially pathogenic (bad) bacteria, loss of healthy balance of gut bacteria.”
Simply put, foods that are high in fats, oils or heavily processed can cause a shift in gut health. Furthermore, other complications such as colorectal cancer may follow dysbiosis.
“Gut dysbiosis, characterized by an imbalance in the gut microbiome, has been identified as a significant contributor to CRC progression,” states Eraghieh Farahani andhis colleagues in a 2025 study published in the Scientifica Journals. “Colorectal cancer (CRC) is a prevalent malignancy worldwide and a leading cause of cancer‐related mortality, influenced by both genetic predisposition and environmental factors.”
With the growth of CRC, researchers are diving into how the gut microbiome plays a role in the overall health of the public. Each region and person has unique microbiomes based on their lifestyle and early life.
Many species of gut microbiome are in utero or during infancy. Mother’s microbiota is passed down through pregnancy and breastfeeding, making up most of the microbiome of their child.
“Many studies have confirmed that susceptibility to CRC or tumor progression is affected by changes in the gut microbiome,” states Jaeho Kim and Heung Kyu Lee in a 2022 study published in the National Library of Medicine. “Reports have shown that the diversity and richness of the gut microbiome decreases in CRC patients.”
Results show there are ways to balance out the gut microbiome at any point, lowering the risks of cancer for individuals fueling their microbiome.
Jandhyala and his colleagues found in their study that, “even very short dietary manipulations can have substantial impacts on the gut microbiota.”
Maintaining a diet which is high in fruits, vegetables and fiber-rich foods and grains, such as a mediterranean diet, is proven to increase diversity in the gut microbiome.
While the rate of colorectal cancer rises, they can be corrected. Maintaining a healthy diet and balancing out the foods that are eaten are proven ways to decrease this risk.
Maybe next lunch go for an apple or salad instead of a donut to satisfy the nutritional needs of the microscopic helpers inside of the gut.