If antibiotics are used wisely, good outcomes are likely. However we have noticed some negative events associated with antibiotics since their initial appearance in 1945. It has been estimated that about 100 trillion microbe cells normally live in and on our bodies.

This is not necessarily a bad thing as many microbes are helpful to us and not all microbes are our enemies. The sum total of all microbes in a healthy adult has been estimated to weigh around three pounds, according to one study.

One researcher has mentioned a “disappearing microbiota hypothesis.” His concern is that with our overuse of antibiotics and obsession with cleanliness through the use of antibacterial soaps and lotions, we may be causing a decrease in microbes that are beneficial to our health.

Infants exposed to antibiotics during the first six months of life may be more likely to be overweight toddlers.

Some strains of mice are more likely to become obese if they possess a certain type of intestinal bacteria that allows them to extract more calories from their diets as compared to similar mice with different gut microbes.

A typical child in this country is thought to be exposed to 10 to 20 rounds of antibiotics by the time they are 18 years old for conditions where the treatment may “do little or no good.”

Thirty percent of births in the U.S. are through Cesarian section. This could prevent a child from being exposed to the “natural biome” that occurs during natural child birth.

Also a “diverse microbial community “is necessary to help start a newborns immune system. Some researchers believe that there is an association between the increased number of Cesarian sections and excessive antibiotic usage which may be one reason for the rise in diabetes, asthma food allergies, obesity, celiac disease and hay fever.

Clostridia difficile is an organism that produces several toxins and is capable of causing severe colitis or inflammation to the lining of the colon. It is usually seen in patients who have been exposed to broad spectrum antibiotics, causing their normal colonic flora to be altered with increased numbers of C. difficile.

Hospitalized patients are susceptible, and 13 percent of patients hospitalized for one to two weeks and 50 percent of those hospitalized for more than four weeks may become colonized with the organism.

Treatment generally involves using other antibiotics, but prolonged recurrences are now unfortunately not uncommon.

A small number of gastroenterologists are now treating some persistent cases with “donor stool” to reintroduce normal flora, and this is done during a colonoscopy.

By the way, the best way to decrease the incidence in hospitalized patients is for health care workers to use good hand-washing technique when caring for patients with C. difficule.

Clindamycin is one antibiotic that has an increased incidence of predisposing individuals to C. difficile colonization, and its use should probably be somewhat restricted.

Please read the article by Richard Conniff in the May 2013 issue of Smithsonian Magazine if you are interested in this topic.

David Keisler is a gastroenterologist and internist in Aiken.