A small set of bacteria helps restore gut microbial health after antibiotic treatments, an international researcher group reports1.

The group that identified this set of 21 gut bacterial species says the knowledge may help devise ways to mitigate the side effects of antibiotic treatment and its associated long-term health consequences.

Antibiotics can disrupt the activity of billions of gut-inhabiting bacteria, increasing the risks of various diseases that impair the immune and metabolic systems. It has been unclear why some individuals recover better than others after antibiotic treatments.

To find out, scientists, including researchers from the Indian Institute of Technology in Chennai, India, analysed hundreds of gut microbiome profiles of patients from three countries. They also investigated how gut microbial population recovered in mice after being treated with specific antibiotics.

They identified 21 bacterial species that promote recovery of the gut microbial population after an antibiotic treatment regimen.

These bacteria contain specific enzymes that help degrade a wide range of host- and diet-derived carbohydrates, thereby serving as primary producers in the gut to provide food and energy for other bacteria that cannot break down the carbohydrates. This helps rebuild the food web in the gut, eventually boosting the recovery of a diverse, healthy microbial community.

It may be possible to promote this recovery through consumption of appropriate prebiotics and probiotics, the researchers say.