Bacteriophages in Human Gastrointestinal Health Applications

Bacteriophages are abundant viruses that naturally inhabit the human gastrointestinal tract, interacting closely with bacterial communities. While their therapeutic potential against bacterial infections has been recognized, clinical evidence remains limited. Here, we review recent randomized, double-blind, placebo-controlled human trials evaluating oral bacteriophage administration for gastrointestinal applications, including treatment of bacterial diarrhea and supplementation in individuals with mild gastrointestinal distress. These studies demonstrate that phage therapy is safe and well-tolerated, with minimal impact on overall gut microbiota composition. There is also some evidence of reduced target bacterial populations and symptom improvement during prolonged use. Additionally, combining phages with probiotics shows promise in enhancing gastrointestinal health. These findings suggest bacteriophages may serve as safe adjuncts or supplements for maintaining gut health and preventing infections, warranting further investigation into their mechanisms and long-term effects within the human microbiome.