How Much Bacteria Live in Our Bodies?
It may be startling, but according to the Howard Hughes Medical Institute (HHMI) of Maryland, we each house two to five pounds (1.0 to 2.26 kilograms) of live bacteria inside our bodies. Bacteria come in good and bad varieties, or more to the point, can be helpful or harmful. While the vast amount of attention is given to bad bacteria because of their potential for creating illness, humans share a necessary symbiotic relationship with many types of helpful bacteria. Some are crucial to our very survival.
HHMI reports that the largest concentration of bacteria in the human body is found in the intestines. Species numbering in the thousands create trillions of silent passengers functioning en masse. The relationship between the different strains of bacteria and the human body is a dynamic one, constantly adjusting to changing conditions.
Probiotics, or the study of treatment through helpful bacteria, is gaining more attention as infections increase from overuse of antibiotics. One familiar example of probiotics is the promotion of yogurt containing live bacterial cultures for easing diarrhea associated with antibiotics. The helpful bacteria in this case are of the lactobacilli strain. Though it is clear through research that helpful bacteria can have a positive effect, as a treatment regimen, their effectiveness is less than sufficient to replace antibiotics, given our current state of knowledge. However, the medical community believes a replacement is exactly what’s needed.
One of the problems with treatment through probiotics is that bacteria within us are not well understood. For example, a dormant or neutral bacterium might become harmful if triggered by conditions that cause it to multiply or change. Bacteria can interact with human cells, causing cell receptors to “grow extensions” to which the bacteria can adhere. Complicating matters, scientists report that at least 50% of these strains cannot be grown in a lab because of the difficulty in creating a suitable environment that simulates the human gut.
Bad bacteria have given rise to some of our most notorious diseases, including cholera, typhoid and scarlet fever. Yet other types of bacteria help to keep us alive and healthy. As scientists come to understand the complicated relationship between bacteria and the human body, they hope to find more natural solutions to disease prevention and treatment.
Written by R. Kayne
