Synbiotics: What are they and are there health benefits?

Our digestive system (our gut) contains numerous families of microorganisms, some of which are considered “beneficial bacteria” as they perform important functions which support our body. The food we eat may help these bacteria to grow and become more active. We help them and they help us. This is what is known as a symbiotic relationship. A similar relationship occurs between probiotics and prebiotics, and when combined this is known as  a “synbiotic”. 

But what are they? Can we get them from our food and how do they benefit us? Let’s take a look at synbiotics, probiotics and prebiotics. 

What Are Synbiotics?

Synbiotics are a combination of prebiotics and probiotics. Synbiotics were created to help the survival of probiotics in the gastrointestinal tract and although prebiotics and probiotics can work alone, they do perform very well as a team. In fact, prebiotics and probiotics have a symbiotic relationship, just like dietary fibre and our gut microbes. 

Synbiotics can be supplied as food combinations in our diet, they are used to improve the survival of beneficial microorganisms in processed food and are available as a health supplement which may be recommended by a healthcare professional. 

To get a better understanding of what a synbiotic is, let's take a look at probiotics and prebiotics. 

What Are Probiotics?

A “probiotic", defined by the The International Scientific Association for Probiotics and Prebiotics is  "live microorganisms which, when administered in adequate amounts, confer a health benefit on the host”. Which basically means it has to offer a health benefit for it to be called a probiotic. The main area probiotics exert their effect is the gastrointestinal tract. You may have seen probiotics strains listed on food labels, or available as supplement tablets, capsules and powders. 

What Are Prebiotics?

Prebiotics are carbohydrates and some non-carbohydrates which are found naturally in foods. They are mostly the indigestible fibre of food we eat and can be food for our friendly gut bacteria, stimulating their growth and activity. 

Some examples of potential prebiotic foods include: tomatoes, artichokes, bananas, asparagus, berries, garlic, onions, chicory, green vegetables, legumes, oats, linseeds, barley, wheat, honey and fibres such as psyllium husks, flaxseed meal and inulin.

You can find synbiotics in some of the foods and food combinations we eat as part of a healthy diet such as: 

• Combining natural yoghurt with chia, flaxseed, fruit and nuts
• Whole-grain cereals such as wheat or oats with yoghurt, banana and a drizzle of honey
• Blending a shake using natural yoghurt drink, kefir milk drink or kombucha and fruit
• Making your salad super by adding sunflower, pumpkin, and feta cheese
• Adding some chia seeds to natural yoghurt, kefir or kombucha drink
• Enjoying sourdough topped with tomato and feta cheese or onion
• Asparagus, onion and tomato on sourdough toasted under the grill

Synbiotics are also found in some processed foods and supplements such as “nutraceuticals” or “functional” foods. Fermented foods are made using live microbial cultures and may contain “live” and beneficial microbes, however not all and these survive travel through the stomach and digestive processes. Foods such as cheese, kimchi (Korean fermented cabbage), kombucha (fermented tea), sauerkraut (fermented cabbage), miso (a paste made from fermented soybean), and pickles may contain “live” cultures, however not always scientifically-supported probiotic strains. 

Research has shown a healthy intestinal ecosystem may improve our health. From a healthy bowel, immune support, healthy mind, skin health and more, studies have shown the benefits obtained from prebiotics, probiotics and synbiotics. Most of this research has been on the use of prebiotics and probiotics. 

Are there health benefits?

Some examples of health benefits include:

Preventing infection from the bad bacteria

Having an abundance of beneficial bacteria residing in our digestive tract may prevent other pathogenic microorganisms  (the bad guys) from being able to take up residence. Our good bacteria eat their food and take over any real estate so they have no way to grow.

Supporting our immune system

The ecosystem of the gut is important for maintaining the balance of our gut microbiome. The gut microbiome is in charge of how our immune system functions. When this system is out of balance (in dysbiosis) our immune system and our health may suffer. Probiotics may support immune cells and our own microbial flora to help with immune balance. Other studies have found synbiotics that may play a role in reducing allergies. 

Improve our digestive function 

Symbiotics may increase our Lactobacillus and Bifidobacterium bacteria amounts which help keep the  balance of good bacteria in our digestive system. Lactobacillus and Bifidobacterium are an important part of our normal intestinal microflora. Fibres and prebiotics support healthy bowel function and conditions such as diarrhoea and constipation. Research has also shown probiotics may help with many bowel diseases reducing symptoms associated with inflammation. Probiotics may aid in the processes of digestion.

Support our mental health

We have all had that gut feeling at one time or another, or felt sick in the stomach when stressed. Did you know our gut microbiome plays a crucial role in communications which occur between the gut and brain (a pathway called the gut-brain axis). Studies have shown probiotics may be able to improve our mood, sleep, and general well-being.

Synbiotics are combinations of probiotics and prebiotics. Probiotics are friendly gut bacteria which may help keep us healthy and prebiotics are the food which helps them survive. They work together, in synergy in our digestive tract. They can be included in a healthy diet or supplemented to promote gut health and may offer many healthy benefits.

Reviewed by Healthylife health experts September 2023