Probiotics and Prebiotics explained
The human gastrointestinal (GI) tract is the host to a complex and dynamic population of tens of trillions of microorganisms, the gut microbiota, which exert a marked influence on the host. Our diet is one of the main drivers in shaping the gut microbiota, which can weigh up to 2kg - bacterial numbers can increase by 1000-fold for a few hours after the consumption of certain foods!
The bacteria present play a crucial role in maintaining the immune system, our metabolism and protection against pathogens. Altered gut bacterial composition (dysbiosis) has been associated with the pathogenesis of many inflammatory diseases and infections.
The two beneficial families and their strains that help us to regulate homeostasis are:
- Lactobacillus (Acidophilus and Salivarius)
- Bifidobacterium (Infantis, Bifidum, Brevis and Longum)
Microbiota homeostasis can become unbalanced through the influence of diet, aging, disease, drugs or stress. To correct dysbiosis it’s advisory to have a diet rich in probiotic foods and eat these on a regular basis as the strains of Lactobacillus or Bifidobacteria bacteria are only resident for up to 12 days in the gut and then they are eliminated via stools.
What are probiotics?
Probiotics are live/active cultures of specific bacteria strains that contain lactic acid bacteria, which can be found in fermented foods and probiotic supplements. Probiotics are your friendly bacteria, increasing your intake increases the number and variety of good bacteria in your gut. Having a healthy balance of good gut microbiota and probiotic microorganisms helps to restore microbial balance, enhance epithelial barrier integrity and function, and reduce immune response and inflammation. To be considered a probiotic, the product must contain 100 million live active bacteria per gram.
What are prebiotics?
In order to maximise the benefits of probiotics, prebiotics are needed for the probiotics to colonise our gut. Prebiotics are the foods that bacteria feed off, they nourish our colonic friendly flora. They are the non-digestible fibre compounds that help feed the probiotics and help them grow.
How do they work together?
Prebiotics help the probiotics do their job well. As prebiotics are mainly fiber and carbohydrate, they bypass digestion, so when they reach the colon, they become fermented by the microbiome.
There are numerous situations which can result in an imbalance of good and bad bacteria in your gut, for instance lack of sleep, prolonged stress or taking a course of antibiotics. Symptoms you may experience if your gut is out of balance include gastrointestinal issues like constipation, diarrhea, bloating and indigestions. Prebiotics work synergistically with probiotics to stimulate the growth of beneficial bacterial like Lactobacillus and Bifidobacteria to help bring back balance.
Author: Kathryn Fielding