We are often told that bacteria are dangerous, cause notorious infections and that we need to keep them away. While there is a bit of truth in that, did you know your gut has a plethora of these ‘friendly’ microbes? Yes, our gastrointestinal tract is home to many microorganisms forming an ecosystem called the gut microbiome. They help the digestion process and also contribute to our happiness and other moods!
The first inhabitants of this micro-ecosystem are the bacteria belonging to the genus Bifidobacterium, which is present in the mother's milk. As we grow, we add a range of bacteria in our gut through the various food we consume and the environment we live in. So far, scientists have identified more than 400 bacterial species from the faeces of a healthy adult, out of which most are of anaerobic bacteria that thrive in the absence of oxygen.
The upper parts of our digestive tract, consisting of the stomach and parts of the small intestine like the duodenum, jejunum, and the upper ileum, has about ten thousand microbes per millilitre of the intestinal secretions. Guess which is the most ‘bacteria-populated’? It’s our mouth! Most of the bacteria reside behind our tongue and pass through the gut with each meal we eat. The large intestine also contains a healthy dose of these microbes—about a 100 billion of them per gram of our stool!
The gut microbes benefit us by filling up our guts so that pathogenic bacteria do not make their way into our gastrointestinal tract. Thus, they act as a barrier which prevents infections from foreign organisms. Incidences of bacterial diarrhoea are due to the imbalance of these gut microbes. The bile juice, produced by our liver, has antibacterial properties and helps in the control of these microbes. The microbial ecosystem also provides its antibacterials like bacteriocins and fatty acids, which stabilises the populations and prevents the implantation of pathogens. Recent studies have shown that the changes in the number and species of gut microbiome play a significant role in obesity and cardiovascular diseases.
After all, gut bacteria are our real friends for life—let's keep them happy with a healthy dose of probiotics!