Even One Course of Antibiotics Can Alter Your Gut Microbiome for Years

While antibiotics save lives, long term or repeated use of it is linked to obesity, type two diabetes, heart disease and even cancer – likely because they disrupt our gut microbiome. A single course of antibiotics causes drastic changes within days and a big drop in the diversity of the microbes. And a new study reveals that certain antibiotics cause changes that can last four to eight years.  

The Swedish study examined 15,000 people split into three groups: people who took antibiotics for less than a year ago, between one and four years ago, and from four to eight years ago.  

Their prescription drug histories were analyzed along with a detailed mapping of each person’s microbiome which researchers completed from fecal samples. Up to three quarters of people had taken antibiotics at least once in the previous 8 years.  A comparison showed that the diversity of the microbiome fell with each additional course of antibiotic use with the greatest impact after the first two courses.   

Clindamycin, fluoroquinolones and flucoloxacillin had the longest lasting impacts, while penicillin made the smallest impact.   The diversity of the gut microbiome recovered most rapidly within the first two years of stopping antibiotics, then recovered slowly.    

This study tells us it’s possible your gut takes years to recover after a course of antibiotics, especially ones that are hardest on gut health. One day, doctors may need to consider this when deciding which antibiotic to prescribe.