Monthly Archives: January 2013

The Good Germs

I have always loved eating out. And we go out to eat quite often. However a change has come in my restaurant “procedure” in the last few years: just after ordering, I bring out my bottle of hand sanitizer and insist that everyone’s hands are properly cleansed. I think that it is a hygienic habit, but my family thinks that one more problem has been added to my already long list of personality disorders.

Today we humans tend to think of “germs” as extremely harmful creatures. But note that our “hatred” for these microorganisms is a very recent development. Till the late 19th century it wasn’t even known that germs cause disease. Before the germ theory of disease was discovered, most people and even scientists attributed disease to “bad air”. If you were to travel to even the most advanced city in the world at any time before the 20th century you would be appalled at the lack of even the basic sanitation that is an absolute must for us today. Till the 19th century, man, rodents, garbage lived right next to each other in the bustling cities of the world. Surgeons had no idea that their hands or surgical instruments needed to be washed/sterilized before an operation!

Okay. So we all hate germs. But that is not the subject of today’s VERITAS. Today we will focus on the “good germs”. And there are a lot of them. The amount of bacteria and other microorganisms in a human body is 10 times the cells of the body. The total number of cells in a human body is about 10 trillion( 10,000,000,000,000) and the total number of germs is ( 100,000,000,000,000). And these germs constitute 1-3 % of your body weight. These germs are just about everywhere: mouth, gut, skin, eyes and at many more places. Most of these germs do not cause disease and a lot of them are in fact extremely useful for us.

The highest concentration of microorganisms in the body is in the digestive tract. These microorganisms are referred to as gut flora. These germs are so useful to us and help in digestion that the gut flora is often referred to as the “forgotten” organ. According to some estimates there are nearly 1000 different types of microbes in the human intestines. Some of these have been identified but a large number of these have not been because it is extremely difficult to grow these species in a lab.

The germs in the gut help us in a number of ways:

1) They aid digestion. There are a number of carbohydrates that we could not digest if our intestines were not full of these germs. We lack the enzymes needed to process certain starches, sugars and fibes. The germs help us digest this stuff. And as a result of this we can get more energy from the food that we eat. Experiments have shown that if we did not have gut flora we would have to eat 30% more to maintain the same body weight.
2) The microbes that constitute the gut flora help save us from diseases caused by harmful germs. The useful germs stick to the intestinal wall creating a wall or barrier that harmful germs are not able to cross. So the harmful germs are not able to infect the intestine. Also the good germs try to kill the harmful germs because they do not want any competition. If we did not have gut flora we would get illnesses of the digestive system very frequently.
3) The gut bacteria help train the immune system to be able to identify pathogens. The good germs stimulate the immune system to produce antibodies to fight pathogens. The immune system learns to fight the harmful pathogens while leaving the good germs unharmed. The gut bacteria also help train the immune system to not react to cells of its own body- allergies. So the presence of gut flora helps prevent allergies.

Okay. So we have established that gut flora is extremely useful for us. The question is : how do we acquire it? The intestines of a fetus is sterile. The acquisition of gut flora happens during or after birth. If a child is born naturally, it acquires gut flora on contact with mother’s feces during birth. However when a child is born by caesarean section, the acquisition of these good germs happens after birth – from air, kissing, or feeding. So great is the difference between the gut flora acquired from normal delivery and c-section that a c-section delivered infant takes 5-6 months more to acquire a healthy concentration of good germs in its intestines. It may sound crazy but young elephants, hippos, koalas and many other herbivores eat the feces of their mother to acquire gut flora. Without a healthy concentration of gut flora these animals would never be able to digest the vegetation that they eat.

But these useful germs also have the capability of causing harm. Remember, they are in the human gut for their own benefit. Some of these germs produce toxins that can be dangerous. Some even produce substances that can cause cancer. These bad effects happen if the numbers are not balanced ie there are too many or too few of these “good” germs.

An excellent way to increase gut flora is to consume probiotics. Many such drinks are available in the market and contain large concentrations of useful germs. For example the popular drink Yakult contains over 100 million Lactobacillus casei bacteria per ml.

Under some conditions the population of good germs is drastically reduced. One example is the usage of antibiotics. When you consume antibiotics to counter an infection, the antibiotic has the sideeffect of killing the good germs in the digestive tract causing an upset stomach. So whenever one consumes antibiotics he/she should also take tablets, drinks or sachets containing large concentrations of useful microorganisms.

Lets now briefly discuss the useful germs found on the skin. The skin has the second highest concentration of germs with over 500 species. These germs also protect us from pathogens by either creating a barrier that pathogens cannot cross or by making the surface of the skin acidic which causes pathogens to die. The acidity on the skin is because of the lactic acid produced by the useful bacteria. The lactic acid mixes with sweat to create conditions in which pathogens cannot grow. Skin flora can also cause disease if their number becomes imbalanced or if the immune system of the person is weakened. Typical skin diseases caused by good bacteria are acne and psoriasis. Also if the skin is damaged, these good germs can enter the body and cause infection. So these germs are good on the skin but not within our bodies.

Note that everything in nature has a balance which if disturbed can cause other problems. So it is okay to wash hands or use sanitizers before eating food. But too much washing hands with soap or alcohol( in sanitizers) can cause the good germs to die and will cause infection by bad germs.

Finally before I end this VERITAS, a little poem by Ogden Nash:

‘The Germ’

A mighty creature is the germ,
Though smaller than the pachyderm.
His customary dwelling place
Is deep within the human race.
His childish pride he often pleases
By giving people strange diseases.
Do you, my poppet, feel infirm?
You probably contain a germ.

Kanwar

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Go wondrous creature, mount where science guides
go measure earth, weigh air, state the tides,
instruct the planets in what orbs to run
correct old time, regulate the sun
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