Bacteria, a prerequisite for life

Bacteria are one kind of microorganisms* that are exceptionally important for human health. They were the first form of life to “populate” the Earth some four billion years ago, and still today they dictate the conditions for our existence. Throughout evolution bacteria and humans have co-existed. Lactobacillus reuteri is one important bacteria that has developed in symbiosis with us.

Bacteria can be found everywhere, for example in soil, water, snow and even in volcanos. Some bacteria live in and on other organisms like animals and humans. Directly after birth the newborn baby is almost sterile but very soon bacteria start colonizing every part of the body - the skin, the mouth and most importantly the gastrointestinal tract. The number and diversity of bacteria continue to increase until the age of three, when it resembles the composition in an adult and then, more or less, remains the same throughout life.

*A microorganism, also called a microbe, is a living organism that is microscopic in size and invisible to the naked eye. Bacteria, fungi, yeast, protozoa, algae and viruses are all examples of microorganisms. Read more

 

Good bacteria we cannot live without

Historically, all we knew about bacteria was that they were causing infections and disease, that they were pathogens. Today we know that bacteria are generally beneficial and together with other microorganisms vital to our health. Just as we cannot live without air and water, we cannot live without our bacteria. One key function is to support the immune system and protect us from disease.

Our bacteria

  • Are our first line of defense against bad bacteria, pathogens
  • Support and educate our immune system
  • Help with digestion and absorption of nutrients
  • Produce certain vitamins, like vitamin B and K
  • May even affect our brain and thereby our mood

 

Health starts in the gut

80% of our immune defense is located in our gut and a balanced microbiota and enough of good bacteria is important for a well-functioning immune system. In our bodies there is a constant battle going on between good and bad bacteria and common disorders, like colic, constipation and diarrhea, are often a sign that the bad bacteria has the upper hand. To achieve a healthy balance the good bacteria need to outnumber the bad with ten to one. The good bacteria educate the immune system, making it ready to fight unwelcome invaders like bad bacteria and toxins.

If bad bacteria for some reason start to exceed it may lead to an imbalance in the digestive system, called dysbiosis. Dysbiosis may cause problems like diarrhea, constipation, bloating, stomach pain and leaky gut. New research indicates that there probably is a strong connection between an unbalanced microbiota and diabetes, obesity and cardiovascular disease. Studies are even suggesting that these conditions can be prevented by taking better care of the microbiota.

Like in all aspects of life, balance is important and as Hippocrates said more than 2,000 years ago “All disease begins in the gut”. This is why it is so important to keep a good bacteria balance in your gut.

Bacteria in the human body

New findings suggest that the number of bacterial cells in our bodies are almost twice as many as our own human body cells. These bacteria are called the human microbiota.

Our microbiota

  • Is built up by some 40 trillion bacteria and most of them are located in our gastrointestinal tract
  • Consists of 400-4000 different species
  • Weighs up to two kg
  • Is extremely essential for human health
  • Being referred to as our new organ

 
 

Good bacteria

Good bacteria can be found in food. Long before refrigerators and freezers, people used bacteria in fermentation to prolong the shelf-life of food. Examples of fermented foods are yoghurt, sauerkraut, and pickled vegetables. Common lactic acid bacteria used for fermentation are Lactobacillus acidophilus, Lactobacillus bulgaricus and Streptococcus thermophiles.

Truly healthy bacteria are known as probiotics. Probiotics are live bacteria that are proven to benefit our health by restoring the bacteria balance in the body and thereby have a positive effect on several health conditions. They are usually consumed as food supplements. Examples of common probiotic strains are Lactobacillus reuteri Protectis, Lactobacillus rhamnosus GG and Bifidobacterium animalis ssp. lactis BB-12.

 

Bad bacteria

A small percentage of all bacteria on earth are pathogenic, meaning they may cause health problems and disease. Food poisoning may be caused by E. coli and Salmonella, sepsis by S. aureus and S. pneumoniae can give pneumonia.

It is important to remember that bacteria of the same species but of different strains can behave completely different. Some species, like E. coli, harbor strains that are extremely pathogenic, like EHEC and ETEC, causing severe diarrhea. On the other hand, some strains ofƒ E. coli are commensals and they are one of the most common bacteria we carry in our gastrointestinal tract.

 

Gatekeepers in the gut

The epithelial lining covers our gastrointestinal tract and works like a skin on the inside. The main task is to differentiate between what should be absorbed and what should not be let into our bodies. To its help it has gatekeepers, so called tight junctions. Their function is to let certain things like nutrients, vitamins and water through, and prevent things like toxins and pathogens, from passing through from your digestive system into your body and your bloodstream.

While a well-balanced microbiota makes the epithelial lining stronger, tighter and better performing, an imbalance in the gut damages the epithelial cells. Leaky gut is a condition caused by a damaged epithelial lining. The gatekeepers, the tight junctions, are letting things through that should normally not enter into the bloodstream. This may lead to several conditions and health problems, for example sepsis, inflammation, allergies and intolerances and digestive problems like IBS.

 

Problems today

The fact that our lifestyle has changed dramatically over the last 50 years has definitely left its marks. Modern ways of living with increased urbanization and altered eating habits have resulted in an imbalance of our microbiota.

 

Our microbiota is negatively affected by the following

  • Usage of antibiotics and other drugs – antibiotics do not only kill pathogens, they also kill our good bacteria.
  • Obsessive hygiene – showering several times a day, using germ killing soap and detergents are depleting our microbiota.
  • Birth by Caesarean section – babies born by C-section don’t pass through the birth canal and are therefore not exposed to the desirable variety of good bacteria from their mother.
  • Poor eating habits – fast food, processed food, coffee and alcohol. It may taste good, but unfortunately your gut bacteria do not thrive on junk food, they need fibers, fresh fruits and vegetables.
  • Stressful living and lack of sleep – both stress and too few hours in bed may lead to changes in composition and reduction of microbial diversity.
  • Excessive exercising – while your workout at the gym is beneficial for your general well-being, professional athletes are often exercising at a level that harms their microbiota and puts their immune system under stress, making them more susceptible to infections.