A new study suggests that consuming sugary foods while taking antibiotics may reduce the diversity of beneficial gut bacteria, potentially affecting health outcomes. The research, published in the journal Nature on September 30, analyzed over 9,400 hospital meals and 1,000 stool samples from blood cancer patients undergoing stem cell transplants.
Antibiotics disrupt gut bacteria diversity, which supports immune function and overall health. The study, led by scientists at Memorial Sloan Kettering Cancer Center, NYU Langone Health, and City of Hope Cancer Center, found that patients who consumed more sweets while on antibiotics experienced greater loss of gut microbiome diversity—a key marker of healthy gut bacteria.
The findings raise questions about whether similar risks apply to people taking antibiotics for common infections, though experts caution against generalizing the results to healthy adults. The study focused on patients undergoing intensive cancer treatments, where microbiome disruption is already a significant concern.
Researchers recommend avoiding sugary foods during antibiotic treatment to preserve gut microbiome diversity. Preserving this diversity has been linked to improved clinical outcomes in cancer patients, including better immune response and reduced infection risks. The study did not examine the effects of sugar on individuals not undergoing cancer treatment.
Antibiotics, particularly broad-spectrum types, kill both harmful and beneficial bacteria, disrupting the gut microbiome. This disruption can lead to side effects such as diarrhea, bloating, and increased susceptibility to other infections. The study suggests that high-sugar diets may exacerbate these effects by further reducing microbiome diversity.
The research team, including co-senior author Dr. Marcel van den Brink, emphasized the importance of maintaining gut health during antibiotic use. However, independent experts like Dr. Opel Baker, a general practitioner not involved in the study, noted that the findings may not apply to healthy individuals, as the study population was already at high risk for microbiome disruption due to cancer treatments.
The study’s authors did not specify which types of sugary foods posed the greatest risk, nor did they quantify the threshold at which sugar consumption becomes problematic. Further research is needed to determine whether the findings apply to broader populations and to identify specific dietary recommendations for patients on antibiotics.