How do prebiotics and probiotics work?
The way prebiotics and probiotics function in our digestive tract is similar to the set-up in the video game Pac-Man. If we think of our digestive tract as the maze, the small ‘Pac-Dots’ that Pac-Man eats as prebiotics, the Pac-Man as a probiotic and the ghosts as bad bacteria, it may help to demonstrate their roles:
- Our digestive tract – is like the Pac-Man maze where food is digested and prebiotics, probiotics and bad bacteria function.
- Prebiotics – are similar to the Pac-Dots that Pac-Man eats as they are the non-digestible fibres that feed the Pac-Man who resembles the good bacteria, or probiotic.
- Probiotics – are like the Pac-Man who consumes the Pac-Dots or prebiotics to grow and thrive in the digestive system.
- Bad bacteria – are like the ghosts as bad bacteria are also present in our digestive tract and compete with the Pac-Man, or probiotics, to live in the gut.
What is a probiotic?
Probiotics are beneficial live microorganisms, found in food or supplements, that can provide us with health benefits when consumed in adequate amounts. Probiotic microorganisms, also called strains, live in our gut and support digestive and immune function as well as our overall health.
What do probiotics do?
Probiotics support health by breaking down indigestible foods in the large intestines, producing vitamins, supporting nutrient absorption and competing with harmful microorganisms in the gut to maintain a healthy balance of bacteria.
Consuming specific probiotics has also been associated with the management of digestive discomfort, a reduction in antibiotic-associated diarrhoea, improved ability to fight the common cold, reduced eczema and colic symptoms in infants, lactose digestion and improved immunity. Initial research is also showing a promising link between specific probiotics and weight management, brain function and blood sugar regulation.
Where can I find probiotics?
Probiotics are available in a number of food sources and also as dietary supplements. Natural food sources that contain probiotics include yoghurt and kefir. Fermented foods that have not been treated with heat such as sauerkraut, kimchi, tempeh, miso and kombucha also contain beneficial live microorganisms. Including these food sources in your diet may be beneficial in ensuring healthy gut functioning and your gut bacteria remaining balanced.
Probiotics are also available in a variety of supplement forms including capsules, powders and drinks.
How many probiotics do I need?
While we understand that probiotics can benefit human health there is no current recommendation on how many or which specific sources of probiotics we should be consuming for general health.
As the microorganisms in probiotics are really small, the potency of a food source or supplement is measured in colony forming units (CFU). This CFU measure tells you how many live microorganisms you can expect to receive from each serve or dose up until the expiry date of the food or supplement.
The number of microorganisms present in foods and supplements can range from 100 million to over 10 billion. More CFUs are not always better and you should choose a dose and strain of probiotics that have been demonstrated in research to help your health condition.
What are the types of probiotics?
There are a number of different types of probiotics and it is important to remember that not all types of probiotics have the same function. If you are looking to manage a particular health concern through the consumption of probiotics you should choose the probiotic strain that research has shown to be effective for your condition and use the product only as directed. We recommend seeking the advice of your healthcare professional prior to using probiotics for any particular health concerns.
Some of the most well researched microorganisms for human health belong to the Lactobacillus and Bifidobacteria species as well as the yeast family Saccharomyces. The table below highlights some of the most well known probiotics along with their potential health benefits.
What is a prebiotic?
Prebiotics are indigestible fibres that are the food source for the beneficial microorganisms that are living in your gut. These beneficial microorganisms help to maintain our health and wellbeing.
What do prebiotics do?
Prebiotics are indigestible by human enzymes so we are unable to break them down in our small intestine. This means prebiotics reach our large intestine still intact for our beneficial bacteria to feed on. Feeding our beneficial bacteria with prebiotics is necessary for our gut health as it allows the good bacteria to grow and contribute to the digestion of food.
Feeding these beneficial bacteria is also beneficial for our overall health as imbalances in gut bacteria have been linked with a number of digestive conditions, as well as allergies.
Established health benefits for specific prebiotics relate to improved digestive function, increased calcium absorption and blood sugar regulation. Prebiotics can also provide energy for our cells as some of them produce short chain fatty acids when they are fermenting in the gut that are used as an energy source.
Where can I find prebiotics?
Prebiotics are naturally found in a number of food sources, including breast milk, and are also available as supplements. Some of the best food sources that contain prebiotics include some select honeys, onion, garlic, leek, Jerusalem artichoke, chicory, banana, dandelion greens, tomato and asparagus. However, the prebiotics that are found in these fresh food sources are often present in low amounts so including prebiotic enhanced foods or supplements may be beneficial to ensure optimal gut health.
Prebiotics are also found in a number of food products such as yoghurt, baked goods and drinks and are available in supplement form. These food products and supplements make it easier to consume higher quantities of prebiotics for gut health. When consumed in adequate amounts these food sources and supplements may help to increase your intake of prebiotics that could not have been achieved through natural food sources alone. We recommend consulting your healthcare professional, if you feel that your dietary intake of prebiotics might be inadequate, so that they can recommend a supplement.
What are the types of prebiotics?
The term prebiotic includes various forms of prebiotics that you will sometimes see used on labels instead of the word prebiotic. These prebiotic forms include oligosaccharides, inulin, fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS).
- Oligosaccharides – are mostly indigestible carbohydrates found in food sources such as honey, asparagus, garlic, chicory, onion, Jerusalem artichoke, tomato, banana and wheat.
- Fructo-oligosaccharides (FOS) – are indigestible carbohydrates that are predominately sugar. They are a type of oligosaccharide. They are found in honey, leek, Brussels sprouts, artichoke, asparagus, garlic, chicory, onion, Jerusalem artichoke, tomato, banana and wheat.
- Galacto-oligosaccharides (GOS) – are indigestible galactose molecules found in the lactose of milk and milk products. They include cow’s milk and breast milk.
- Inulin – is an indigestible carbohydrate and type of dietary fibre. It is found in plant sources including chicory, onion, Jerusalem artichoke, banana and dandelion.
- Honey Oligosaccharides (HOS)- are oligosaccharides found in honey. Honey may contain as many as 24 individual oligosaccharides, including fructo –oligosaccharides and galacto-oligosaccharides.
What is the Difference Between Fibre and Prebiotic Fibre?
While all prebiotics are classified as fibre, not all fibre is a prebiotic. Prebiotics have some specific properties that not all fibres have. These properties are what allows them to help support digestive health and wellbeing.
Dietary fibre is an edible and indigestible component of plants that is consumed for its health benefits. Fibre is resistant to digestion and absorption in the small intestine, so is able to ferment in the large intestine. Fibre includes soluble fibre, insoluble fibre and resistant starch.
Soluble fibre helps to slow the digestion process in our stomach and helps keep us feeling satisfied. It can be found in fruits, vegetables, oats and legumes.
Insoluble fibre supports regular bowel movements by softening the contents of our bowels. It also helps to keep us feeling satisfied and our gut environment healthy. Insoluble fibre is found in whole grain breads and cereals, nuts, seeds and the skin of fruit and vegetables.
Resistant starch (a form of soluble fibre) ferments in the large intestine as it isn’t digested or absorbed in the small intestine. This allows it to encourage the growth of beneficial bacteria and promote gut health. Resistant starch is found in banana flour, slightly green bananas, oats, legumes and cooked and cooled potato and rice.
Fibre is essential for healthy gut function, allowing regular bowel motions, and maintaining blood sugar levels. The consumption of fibre can help with appetite control and maintain a healthy body weight.
A prebiotic is an indigestible fibre that is selectively fermented by beneficial bacteria in the gut to benefit an individual’s health. This is usually promoting the growth of Bifidobacteria or Lactobacilli bacteria in the gut, two types of bacteria that have been associated with health benefits.
Specific prebiotics are able to provide health benefits as they improve the composition of our gut bacteria. This means they support our beneficial gut bacteria to grow and prevent the growth of our potentially harmful gut bacteria. Prebiotics have the potential to help maintain digestive function, support bowel regularity, assist mineral absorption and help regulate blood sugar levels.
To be classified as a prebiotic the fibre must:
- Resist gastric acid, enzyme breakdown and absorption in the upper digestive system
- Be fermentable by gut bacteria
- Encourage the growth and/or activity of beneficial gut bacteria
These are the key differences between fibre and prebiotics. While some fibres may make it to the large intestine unaffected by digestion and absorption in the small intestine, they aren’t always entirely fermented by beneficial gut bacteria and therefore aren’t able to encourage the growth of the beneficial gut bacteria.
As prebiotics and fibre have different roles and health benefits, including adequate fibre and prebiotics in your diet is recommended. This is of particular importance as the amount of fibre individuals are consuming in our modern diet is often less than half of the recommended amount. Combine fibre rich foods such as vegetables, whole grains, oats, legumes and nuts combined with prebiotic rich foods such as prebiotic honey, Jerusalem artichoke, onion, leek, garlic and chicory to support optimal health and wellbeing.
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