Human large intestines usually contain trillions of bacteria. Far more bacteria than we have cells in our body. Current research is still providing us with details of how these bacteria affect us. But we do know that they have a huge role in our health and well being. This is why supplements of probiotics and prebiotics are appearing on the shelves. But what are they? And what exactly is the difference?
The estimated 100 trillion bacteria of our personal microbiome comprises many different species. The actual number of species varying from about 500 to 1000. A greater number of species usually means a healthier gut and thus a healthier body.
Some bacterial species such as Lactobacillus and Bifidobacterium are friendly and perform beneficial functions. The presence of harmful species increase the risk of disease. Whilst some microbial species are normally present in small numbers without causing harm, if their numbers increase this can produce a harmful imbalance in the gut microflora.
All being well, a healthy diversity of the microbiome, established from birth onwards, can persist throughout life. But there are several factors that can change the balance and numbers of bacteria. Factors which reduce or eradicate bacteria include poor diet and certain medications.
As more people learn about the importance of a healthy gut microflora the popularity of probiotics has increased. Probiotics are sources of beneficial bacteria. They are available in supplements or certain foods. Common food sources are the commercially produced fermented milks or bio-yoghurts. Consumed on a daily basis to increase the numbers of beneficial bacteria in the gut.
These probiotic sources provide a relatively small number of bacterial species. Perhaps even a single species of bacteria. And the available brands can vary in their effectiveness.
To boost the number of good bacteria, probiotics must survive digestion and reach the large intestine. After all, the purpose of stomach acid is partly to protect against invasion by bacteria. If they reach the large intestine they must compete for sites with incumbent microbes and multiply. Since competition for sites is strong the introduced species are often transient and easily eliminated. And so the probiotics must be regularly consumed to maintain any benefit.
Research indicates that probiotic supplements are safe and are beneficial in certain circumstances. Especially after a course of antibiotics, to replenish the gut microbiota. Or perhaps to aid the restoration of the balance of bacteria after a case of travellers tummy. So, probiotics can have their uses.
Another way to maintain a healthy gut is to nourish the existing friendly bacteria with the foods that they thrive on. These foods are the prebiotics. By nourishing the pre-existing beneficial bacteria they encourage their multiplication and population of the gut. This improves the balance of gut microbes on a longer term basis.
Prebiotics are forms of carbohydrates that resist digestion in the upper gastrointestinal tract. They reach the large intestine relatively intact where they are fermented by colonic bacteria.
Prebiotics occur in foods such as legumes, vegetables and fruits. So eating a wide variety of fruits and vegetables every day can help to nourish your healthy gut bacteria. Prebiotics are also available in supplement form.