Prebiotics and probiotics are not terms that are strangers to any of us. Prebiotics and probiotics are most commonly consumed to boost gut health by improving the diversity of the gut microbiome. Research has shown that different individuals may have varying dietary responses due to our unique gut microbiota. The distinctive features of each person’s intestinal flora mean that there is no one-size-fits-all approach and people may thus benefit from personalised nutrition strategies.
What are prebiotics?
Prebiotics, as defined by the International Scientific Association (n.d.) for prebiotics and probiotics, are “a substrate that is selectively utilised by host microorganisms conferring a health benefit”. In other words, prebiotics are utilised as food for the beneficial bacteria in your microbiome. Prebiotics can be found in your everyday fruits and vegetables in the form of plant fibres and resistant starch. It is good to note that although prebiotics may potentially be found in the form of dietary fibre, not all dietary fibre is prebiotic.
Prebiotics are commonly found in vegetables with complex carbohydrates, such as potatoes and carrots. Your body is unable to digest these fibres and starch, so they are passed along the gastrointestinal tract and become sustenance for the bacteria in your gut.
What are probiotics?
Probiotics are defined by the International Scientific Association (n.d.) for prebiotics and probiotics as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”. Essentially, probiotics are strains of bacteria that are beneficial to us. They mainly promote health in intestinal cells and also help to maintain a balance between good gut bacteria and pathogens.
Some examples of common probiotic-containing foods are yoghurt, kombucha, and kimchi. These foods have been fermented with different bacteria species. Probiotics have been shown in various clinical studies to have a positive effect on gastrointestinal diseases. The most common strains of probiotic microbes include Lactobacillus, Bifidobacterium, Lactococcus, Streptococcus, and Enterococcus.
A probiotic supplement, on the other hand, may contain live strains of beneficial microbes. The WHO, FAO, and EFSA (the European Food Safety Authority) have guidelines that require the specific strain of microbe used to meet certain safety and functionality criteria. This is because different strains of microbes are commonly marketed to specific health conditions. An example is the use of Bifidobacterium strains to treat Irritable Bowel Syndrome (IBS).
What are the differences between prebiotics and probiotics?
Although they essentially work in harmony with each other to enhance overall gut microbial diversity and may sound the same, pre- and probiotics are rather different.
Probiotics contribute by adding various strands of bacteria to populate the current bacteria in the gut. Prebiotics are naturally occurring carbohydrates used to stimulate and support the growth of the microorganisms existing in the gut.
The shelf life of products containing prebiotics is generally longer than those containing probiotics. Prebiotics are also chemically and physically more resistant to processing than probiotics are.
However, as with any food product, too much of a good thing may still cause adverse effects. Excessive consumption of prebiotics may result in flatulence or diarrhoea. These effects have not been observed in cases of excessive probiotic consumption.
The effects of pre- and probiotics on the gut
With an increased intake of prebiotic and probiotics, your gut microbiome diversity will increase and flourish. A more diverse gut microbiome is more able to adapt to dietary changes to benefit your health even more.
The oral consumption of probiotics has shown to directly increase the abundance of beneficial bacteria in your gut rapidly while limiting the growth of harmful bacteria. This aids in restoring and maintaining the stability of your gut microbiome.
Prebiotics help to promote the growth and activity of your gut bacteria, protects them from being destroyed by the immune system, and can also increase the abundance of beneficial bacteria in your gut.
Personalised nutrition uses your response to different diets to create a unique diet design. By understanding your unique microbiome, personalised nutrition further enhances your response to specific diets.
Prebiotics are ideally consumed from fresh food. Food items such as garlic, onions, leeks, asparagus, bananas, barley, oats, apples, cocoa, and seaweed are high in prebiotics that can help in digestion and build up your gut health.
Prebiotics may be taken as an alternative to probiotics or as a supplementary method to probiotics.
A common use of probiotics is to restore the body’s natural gut microbiota balance after antibiotic treatment, which targets beneficial bacteria in addition to harmful bacteria.
Probiotics can also be consumed in the form of fresh food or supplements. Some of the food items include yoghurt, sauerkraut, tempeh, kimchi, miso, kombucha, pickles, and some cheeses. Some of the fermented foods that are listed here naturally contain probiotics.
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About the author
Bibi Chia is the Principal Dietitian at Raffles Medical Group, with vast experience in the public health, healthcare, and food industries. She is particularly interested in the prevention of nutrition-related non-communicable diseases.