Gut bacteria may not fully replenish after antibiotic use: study

A new study has found that gut bacteria only partially replenishes in healthy individuals following antibiotic use. Scientists tested the effects of antibiotics on gut bacteria in heathy men, finding that it nearly eradicated the "good bacteria," which then slowly replenished over the following half-year. Unfortunately, not all of the beneficial bacteria returned and researchers found that some unwanted bacteria also established itself in the gut.

Gut bacteria, often called "good bacteria," has been increasingly associated with human health, potentially offering benefits for mental health, immune function, and more. Disruptions to gut bacteria, however, may pave the way for diseases and disorders, past research has found, including issues like inflammation, diabetes, obesity, and depression.

Antibiotic medication offers an excellent way to deal with unwanted bacteria infecting a body, but has long been thought to also disrupt gut bacteria. The new research, which was led by the University of Copenhagen and Steno Diabetes Center Copenhagen, studied the effects of three antibiotics on this bacteria, as well as the effects over following months as the bacteria replenished.

In health individuals, the beneficial gut bacteria was able to replenish over six months following antibiotic use...except for nine common, beneficial strains of bacteria, that is. As well, the study found that some possibly "non-desirable" bacteria had also colonized in the gut of healthy volunteers.

The volunteers were given three "last resort" antibiotics over the course of four days. These drug cocktails were designed to imitate the type of antibiotics that may be administered in an ICU setting, according to the researchers.

Study lead Professor Oluf Pedersen of the Novo Nordisk Foundation Center for Basic Metabolic Research explained:

In this case, it is good that we can regenerate our gut microbiota which is important for our general health. The concern, however, relates to the potentially permanent loss of beneficial bacteria after multiple exposures to antibiotics during our lifetime. There is evidence that Western populations have a considerably lower diversity of their gut microbiota that native people living in certain parts of Africa and Amazonas. One possible explanation for this may be the widespread use of antibiotics in treatment of infectious diseases.

SOURCE: University of Copenhagen