Antibiotics, which are commonly added to animal foods, alter our gut flora when we consume animal products. Moreover, antibiotics, which treat our numerous infections, reach our gut flora in much higher concentrations and exert a more profound effect. Antibiotics, given inappropriately for viral respiratory infections, or given in unnecessarily prolonged courses for urine and other types of infections, increase the already burdensome antibiotic adverse effects on our gut flora. The increasing use and abuse of antibiotics during the last one hundred years has weakened our gut defenses, leading to more frequent gut infections.

One of these serious gut infections is caused by a poisonous, spore-forming, bacterium called Clostridium difficile, better known as C. diff. This bacterium, which is a close cousin of the gas gangrene bacterium of First World War fame, has become a frequent agent of antibiotic colitis, especially in elderly, hospitalized and nursing-home patients, and is also wielding increasing morbidity and mortality worldwide. The two toxins (A & B) elaborated by the bacterium are its main virulence factors. They enter and kill the intestinal cells, which line the gut walls, causing purulent scabs, ulcers, and necrosis.

In 1935, Hall and O’Toole first isolated C. diff from the stools of healthy neonates. The first clinical reports of devastating antibiotic colitis appeared in the late 1970s. Since then, the incidence has steadily increased, the infection has spread beyond institutions into communities, and is now also attacking the young and healthy.

The diagnosis by colonoscopy is easy when the infection is severe because of the visible devastation and the severe symptoms of fever, low blood pressure, and multi organ failure. However, when the infection is mild or moderate, in a healthy host, it may only cause protracted diarrhea and nonspecific symptoms. In such cases, testing for toxins A & B in the stools may help when these tests are positive. However, these tests are often negative, and the diagnosis will have to be made clinically.

To further complicate matters, the C. diff bacterium may colonize the colon without causing symptoms. In such cases, the stool tests for toxins A & B may remain positive for prolonged periods, with no clinical symptoms that require treatment.

The first goal of treatment is to stop the offending antibiotics, which allows the normal fecal flora to recover. In most situations, this causes the diarrhea to resolve without further interventions. When it does not, therapeutic trials with Metronidazole, Vancomycin, or Rifaximin are helpful, but the disease recurs in 20% after the first treatment, in 40% after the second treatment, in 60% after three or more treatments. In such cases, prolonged suppression with small doses of Vancomycin etc. or treatments with fecal transplants may become necessary. When the disease leads to toxic megacolon, a rare and deadly complication of total colon necrosis, surgically removing the entire colon may be the only remaining life saving option. In the USA alone, C. diff colitis kills about 14,000 persons per year.

The spores of C. diff, which resemble dry seeds, are hard to kill with cleansing products and survive on dry surfaces for prolonged periods. In medical settings, and now in many community settings, they can be cultured from most surfaces. When these surfaces are touched by innocent hands, the bacteria are unwittingly carried to the mouth where they are ingested. They reach the intestines because spores can resist stomach acid. Once in the intestines, they germinate, compete with the normal bacterial flora, and establish a state of colonization or active infection. Medicines that suppress stomach acid increase the incidence of C. diff infections because more spores survive the tempered acidic environment of the stomach and reach the intestines.

Many antibiotic diarrheas are not caused by C. diff infection, and these respond well to stopping the antibiotics. Currently, 50% of all antibiotics prescribed are considered inappropriate and harmful. Nevertheless, such over prescribing continues to fuel the global epidemic of antibiotic, C. diff colitis. Prescribing antibiotics sparingly and for as short a period as possible are the current strategies for halting the C. diff epidemic. Although public acceptance of these strategies is on the rise, many patients continue to demand antibiotics when they have a chest cold or sinus drainage, and many providers still nonchalantly prescribe them.

Whereas it takes animals thousands of years to evolve in accordance with environmental demands, it takes bacteria only a few weeks to evolve defenses against environmental challenges. Consequently, bacteria are becoming increasingly resistant to the antibiotics we have, and it is becoming harder to develop antibiotics to which bacteria are sensitive. Responsible antibiotic prescribing may be the only remaining strategy to halt this dangerous trend of growing antibiotic resistance and spreading C. diff colitis.