Informing ourselves as to what goes into our bodies literally is a matter of life or death these days. It is becoming more evident that cures for disease do not lie within vaccines or antibiotics. Even the The World Health Organization agrees saying: “The best vaccine against common infectious diseases is an adequate diet.” Today, it is imperative that we understand the role of microbes, how they can cause disease, who are vulnerable, and what we can do to lessen their devastating effects. With the environment and our food becoming more polluted, it is in our own best interest, and those we love, to come to an all-round understanding of many issues. This section on microorganisms is but one piece in the puzzle – but all ultimately fit together.
In the past fifty years, more people have died from malaria, tuberculosis, and AIDS than from all the wars. Infectious and parasitic diseases have been the biggest killers. In 1998 alone, nearly ten million people died from “simple” infections like those involving the respiratory system. Of that number, 3.5 million were children under five years of age. During the same year, the worldwide infection of AIDS reached thirty million people, with 2.2 million deaths, bringing the total to more than fourteen million deaths since the “epidemic” began almost twenty years before. However, to put this into proper perspective, the AIDS “epidemic” still does not come close to the twenty million people who died in a two-year period from the 1918 influenza pandemic.
The average person carries around about 100 billion microbes on the outside of his body. Inside, there are about fifty trillion, which add three to four pounds to his overall weight (and 90% are not even of human origin!). During a normal bowel movement, there can be 100 trillion of these microbes released into the environment. This figure excludes the many excreted through diseases of diarrhea or dysentary, and it is this one bodily function alone that passes on most diseases. If proper handwashing is not done immediately afterwards (including after diaper changes), microbes are left on the hands to be transferred to food, objects, and, yes, even directly into the mouth. Many infectious diseases could be averted simply by paying attention to this one act alone.
The reason that dysentary causes numerous infections so quickly is seen in the spread of cholera, for example. One infected person can excrete more than ten million million bacteria each day (or upwards of ten to twenty liters of fluid, all containing the bacteria). Technically, only one million is needed to cause disease when ingested. Therefore, that one diseased person can potentially infect as many as ten million others every single day. But, for other bacteria, it takes far fewer than one million to infect a person. For example, Campylobacter requires only 500 cells to produce disease, while Shigella needs only 200 cells to make one ill.
A disease becomes infectious if it is caused by a specific microorganism and/or from the toxin it may produce. An infectious disease is generally termed “contagious” if it can be passed from one person to another. But, as with most things, there are exceptions. Although AIDS/HIV and syphilis are considered infectious diseases, they are not regarded as contagious because they require something additional for their spread – as sexual contact. Intestinal infections can be caused by viruses, bacteria, or parasites; and these can contribute to food intolerances – which doctors have known for many years. Antibiotics can also compound the problem. Using heavily chlorinated tap water is another means of reducing the normal flora of the bowel, allowing for pathogens to take hold and grow because the normal flora has been altered.
There are basic routes of transmission for microorganisms to cause infection in humans. The above mentioned fecal/oral route is but one way. Others include:
- airborne via sneezes, coughs, etc., even shouting
- by such direct contact such as shaking hands, touching an infected person, kissing, etc.
- indirect contact as in touching contaminated surfaces such as doorknobs, utensils, faucets, kleenex, body fluids, etc.eating contaminated food or drinks
- sexual contact.
Germs cannot penetrate intact skin. They can only enter the skin where there is a break or through the mucus membranes of the eyes, nose, mouth, genitals, urethra, and anus. Breaks in the skin can be anything from a pin prick or needle stick to cuts, sores, wounds, or incisions. Other conditions also help in the spread of infectious organisms, especially an overcrowded and unsanitary environment. Recirculated air suppliers, as well as all types of water supplies, are also sources of infectious transmission.
Microorganisms are interesting creatures, easily giving rise to many a science fiction scenario. However, a few facts are quite real. For instance, for every gram of fertile soil, there are an estimated 100,000,000 microbes (the more bacteria, the healthier the soil). For most bacteria, it would only take about 1000 of them, laid end to end, to fit on the head of a pin. Microbial life on earth is approximately twenty-five times the total mass of all living creatures. Some bacteria are capable of dividing every twenty minutes; and, if not kept in check, they would divide at the following rate: one bacterium at 6 AM, ¼ million by noon, with 68 billion by 6 PM! With the right condtions, and being left alone, bacteria could multiply at such a rate as to be greater than the earth’s mass in just three days.
However, microbes are very necessary. They constitute roughly 90% of all living matter on this planet, as well as being responsible for most of the chemical changes that occur, involving all living things. As far as nutrients are concerned, microbes need at least one nutrient, with the exception of Vitamin C and the fat-soluble vitamins. As far as scientists can determine, these nutrients are not required by any known bacteria, fungi, or algae; but they are not sure as to whether protozoa require them or not. They do know that viruses do not require any nourishment at all.
All living things can be classified within seven levels, going from the general to the specific: Kingdom, Phylum (plural phyla), Class, Order, Family, Genus, and Species. From there, each category is broken down still further. As far as Kingdoms are concerned, most scientists agree that all organisms can be classified within five: Animals, Plants, Protists, Fungi, and Monerans (prokaryotes). Technically, viruses do not fit well into any of these categories, but are often placed with prokaryotes for the sake of convenience. Disease-causing organisms can also fit into five categories, from the simplest to the most complex: viruses, bacteria, protozoa, fungi, and parasites.
There are some basic differences in microbes. Here are some helpful terms to show their diversity.
- Thermophiles like it hot.
- Mesophiles like it warm.
- Psychrophiles like it cold.
- Halophiles like it salty.
- Acidophiles like it acidic.
- Alkalophiles like it alkaline.
- Barophiles like high pressures.
- Heterotrophs need organic matter for food.
- Autotrophs make their own food from carbon dioxide.
- Phototrophs use light energy to make their own food.
- Chemo-autotrophs use chemical energy to make their own food.
- Aerobes need air to grow.
- Anaerobes will die in air.
- Facultative anaerobes can grow with, or without, air.