It’s Not Nice to Mess with Normal Flora
By Richard P. Holm, MD
An elderly hospitalized pneumonia patient was getting better after three days on powerful antibiotics when bloody diarrhea, cramping, and fever began and his overall condition started to deteriorate. His stool test was positive for C. difficile and he got better on a different type of antibiotic. This happened because the abundance of microscopic organisms which normally lived, grew, and replicated within his body were weakened or destroyed by the pneumonia antibiotics, resulting in the loss of an important balance of nature within our bodies.
It sounds like a sci-fi movie, but this is NOT fiction. Scientists have discovered large numbers of micro-communities around and within every living plant and animal. Surprisingly many of these ‘invaders’ are necessary and helpful to the host, although some have no known benefit and some are harmful. These microscopic organisms include bacteria, fungi, viruses, and parasites and are called the ‘normal flora’ or ‘microbiota’ (like oat-uh).
Helpful non-human examples of microbiota include bacteria that fix nitrogen on alfalfa, fertilizing plant and surrounding soil; or organisms living in the rumen of cattle that make grass turn into absorbable nutritious food. There are about 10X as many non-human microbial cells in our body as human cells, and they exist almost everywhere, including mammary glands, skin cells, lungs, mouth, and eyes. The area where most microbiota reside, however, is within the gut or gastro-intestinal (GI) tract.
From the first minute after birth, the baby’s gut is exposed to a microorganism-rich world following their travel through the vaginal canal, followed by exposure to skin and milk flora while suckling at mama’s breasts. Over the next year, the baby’s microbiota develops and helps the infant break down dietary fiber and fat while simultaneously serving as a barrier to invasive organisms. It also helps synthesize vitamins, metabolize harmful toxins, reduce inflammation, enhance immune activity, and produce hormones.
When human flora encounters radical changes, often resulting from non-specific destruction by antibiotics, inflammatory and autoimmune disorders may occur; antibiotics can cause overgrowth of invasive bacteria, the most common of which is called Clostridium difficile, or C. dif. This type of invasive overgrowth was responsible for about a half million infections in 2011, with 29,000 of those dying within the first month.
Take home message: avoid antibiotics unless necessary. It’s not nice to mess with normal flora.