Study: Gut bacteria nearly recovers after antibiotics regimen

Oct. 23 (UPI) -- Gut bacteria, which helps stave off chronic diseases, nearly recovered six months after a cocktail of three injected antibiotics, according to a study in Denmark.

The findings, which were published Tuesday in the journal Nature Microbiology, refute speculation that repetitive use of antibiotics deprives people of gut microbiota and leads to adverse health effects, including obesity, diabetes, asthma and inflammatory intestinal disorders.

The gut is part of the digestive system that breaks down foods and absorbs nutrients that support our body's functions. The mouth, esophagus, stomach and intestines are part of the gastrointestinal tract.

"We show that the gut bacterial community of healthy adults are resilient and able to recover after short-term simultaneous exposure to three different antibiotics," study leader Dr. Oluf Pedersen, a professor in basic metabolic research at the University of Copenhagen, said in a press release. "However, our findings also suggest that exposure to broad-spectrum antibiotics may dilute the diversity of the intestinal bacterial ecosystem."

With this in mind, Pedersen urges caution in using antibiotics.

"Antibiotics can be a blessing for preserving human health but should only be used based upon clear evidence for a bacterial cause of infection," Pedersen said.

Pedersen and his colleagues from the University of Copenhagen as well as the Steno Diabetes Center Copenhagen studied three antibiotics given to 12 young healthy men for four days. Administering of these so-called "last-resort" antibiotics -- meropenem, gentamicin and vancomycin -- was designed to mimic actual treatments in intensive care units.

The cocktail initially caused an almost complete eradication of gut bacteria. But there was gradual recovery of most bacterial species over six months.

Still missing were nine of the common beneficial bacteria. In addition, some new potentially non-desirable bacteria had developed in the gut.

The gut contains trillions of bacteria, including hundreds of different bacterial species with antibiotic-resistant genes. The genes led to the replenishment of bacteria in the gut.

"In this case, it is good that we can regenerate our gut microbiota which is important for our general health," Pedersen said. "The concern, however, relates to the potentially permanent loss of beneficial bacteria after multiple exposures to antibiotics during our lifetime."

He noted that Western populations have a considerably lower diversity of their gut microbiota than people living in certain parts of Africa and Brazil.

"One possible explanation for this may be the widespread use of antibiotics in treatment of infectious diseases," Pedersen said.