From the microbiome to medicine: probiotics and their effects on cancer

Abstract

The human gastrointestinal (GI) tract plays a major role in maintaining health by regulating the immune system and protecting against pathogens. The GI tract harbours a large and diverse community of beneficial microorganisms, which play a crucial role in keeping us healthy. Disruptions of the microbiome, known as dysbiosis, have been increasingly linked to disease development, such as cancer, particularly within the GI tract, as well as causing an influx of pathogenic bacteria such as Helicobacter pylori and Fusobacterium nucleatum. Many cancers occur within the GI tract. While treatments such as chemotherapy and radiotherapy are effective, they can disturb the microbiome, therefore causing side effects and potentially increasing disease progression.

Probiotics are beneficial microorganisms that give health benefits when consumed in adequate amounts. They can restore the microbiome whilst also having anticancer effects. Certain strains have been shown to enhance immune response and strengthen the intestinal barrier. They can also work synergistically with chemotherapeutic drugs to enhance response to treatment. Many findings are derived from in vitro and animal studies, with few clinical studies, but suggest that probiotics can be used as a prevention strategy or as an adjunct to treatment.