Historically, all we knew about bacteria was that they were pathogens (causing infections and disease). Today we know that bacteria can be 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:
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. The good bacteria educate the immune system, making it ready to fight unwelcome invaders like bad bacteria and toxins. To achieve a healthy balance, the good bacteria need to outnumber the bad with ten to one.
If bad bacteria start to exceed, it may lead to an imbalance in the digestive system, called dysbiosis. Dysbiosis may cause problems like diarrhoea, constipation, bloating, temporary stomach pain and leaky gut. Also, 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 and gut health.
The fact that our lifestyle has changed dramatically over the last 50 years has definitely left its marks. Modern ways of living with increased urbanisation and altered eating habits have resulted in an imbalance of our microbiota.
The epithelial lining covers our gastrointestinal tract (GIT) 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 harmful 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 , intolerance and digestive problems like irritable bowel syndrome (IBS).
The main task of our inner skin, the epithelial lining, is to differentiate between what should be absorbed and what should not be let into our bodies.
Good bacteria can be found in food. Long before refrigerators and freezers, people used bacteria in fermentation to prolong the shelflife 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 Limosilactobacillus reuteri Protectis®, Lactobacillus rhamnosus GG and Bifidobacterium animalis ssp. lactis BB-12.
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, causing severe diarrhoea.
On the other hand, some strains of E. coli are commensals and they are one of the most common bacteria we carry in our gastrointestinal tract.