TOPLINE: 

Patients who used antibiotics, especially for gastrointestinal (GI) infections, had a higher risk of developing irritable bowel syndrome (IBS) than those who did not use antibiotics.

METHODOLOGY: 

• Antibiotic use has been linked to changes in gut microbiota and an increased risk for new-onset IBS. Prior studies have examined the associations between antibiotic use, gut microbiota, and IBS both generally and specifically after GI infections, but findings have been inconsistent.
• Researchers conducted a systematic review and meta-analysis of three databases through June 2025 to compare new IBS diagnoses in patients who received antibiotics and those who did not.
• They included studies from multiple countries and excluded people with prior IBS. Follow‑up duration in the included studies ranged from 6 to 204 months.
• The primary outcome was the incidence of IBS after antibiotic exposure, with incidence rates reported per 1000 person‑years.
• Incidence rate ratios (IRRs) were compared, and heterogeneity was evaluated. Study quality was assessed using the Newcastle-Ottawa scale. 

TAKEAWAY: 

• The analysis included 31 studies with 422,350 patients (244,632 antibiotic users and 177,718 nonusers); median ages across studies ranged from 5 to 59.9 years. Most studies were rated as high quality.
• The pooled incidence rate of IBS was 26% among antibiotic users and 20% among nonusers (all included studies; I²= 100%). Based on the pooled IRR, antibiotic users had a 30% higher risk for IBS than nonusers (28 studies; P = .008; I² = 97%).
• In sensitivity analyses restricted to studies in which antibiotics were used for GI infections, antibiotic users had a 71% higher risk of developing IBS than nonusers (15 studies; P = .007; I² = 79%).
• Antibiotic use for non-GI infections was not significantly associated with an increased risk for IBS (16 studies; I² = 98%).

IN PRACTICE:

“While antibiotics remain essential for managing severe bacterial infections, unnecessary or broad-spectrum antibiotic use — particularly during gastrointestinal infections — should be carefully weighted against potential long-term consequences on gut health,” the authors of the study wrote.

SOURCE:

The study was jointly led by Luigi Colecchia, MD, and Giovanni Marasco, MD, PhD, University of Bologna, Italy. It was published online in the American Journal of Gastroenterology.

LIMITATIONS: 

Many studies were retrospective, possibly introducing recall and selection biases. Important confounding factors such as diet, genetics, mental health, and concomitant medications were not consistently reported and could not be adjusted for. Details on antibiotic class, dose, and duration as well as infection severity were also inconsistently reported.

DISCLOSURES:

The study did not receive any external funding. Two authors reported receiving payments or honoraria from multiple pharmaceutical and healthcare companies. Some reported serving on data safety monitoring boards or advisory boards, and others declared having consultancy roles, business interests, or other financial and nonfinancial relationships with industry.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.