High Sugar Intake Disrupts Gut Microbiome During Antibiotics
A new study reveals that excessive sugar consumption during antibiotic treatment significantly reduces healthy gut microbial diversity.
Updated on Oct. 25, 2026 in Nutrition
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Researchers analyzing 9,000 meals from 173 hospitalized patients found that high sugar intake is linked to a notable reduction in gut bacterial diversity. This decline is particularly significant for patients undergoing antibiotic treatments.
Why it matters
Understanding the dietary impact on gut health during antibiotic use could help improve patient recovery outcomes. Simple sugars may provide a fuel source for drug-resistant bacteria to proliferate while other beneficial microbes struggle to survive.
For every 100 grams of sugar consumed in the two days prior to stool sampling, hospitalized patients on antibiotics saw a 24 percent reduction in microbial diversity. The findings are based on 9,000 tracked meals across 173 patients.
The players
NYU Langone Health
This academic medical center is the primary professional affiliation for the lead microbiologist involved in the study.
King's College London
This research university is the professional affiliation of the nutrition scientist who contributed to the study findings.
The details
Sugary foods and drinks correlate with an increase in Enterococcus bacteria, which can become more dominant when healthy gut flora are suppressed by antibiotics. Animal experiments in mice confirmed that a sugar-rich diet exacerbates the growth of these drug-resistant bacteria following antibiotic exposure.
Timeline
Patients' sugar intake was measured during the two days before each stool sample was collected.
The Big Picture
This research is part of the ongoing effort to map the Human Microbiome Project's goals regarding how external factors shape microbial health. The findings mark a specific departure from general dietary advice by demonstrating how high sugar intake directly contradicts the recovery of gut diversity during antibiotic exposure.
Patients currently undergoing antibiotic treatments may consider monitoring their sugar intake to support healthy gut microbial recovery. These findings suggest that limiting sugary foods could potentially prevent the overgrowth of harmful, drug-resistant bacteria in the digestive tract.
The takeaway
Maintaining a lower-sugar diet during a course of antibiotics may help preserve the beneficial bacteria in your gut. Future research is required to determine if these specific findings extend to outpatient populations who have different dietary habits than hospitalized patients.
Further reading
Learn more about dietary impacts on the digestive system in our Nutrition section.
Live Poll
Do you adjust your sugar intake when taking antibiotics to protect your gut health?
