To understand the role of probiotics and prebiotics, we must first understand the gut microbiome and its role in our bodies.

What is the Gut Microbiome?

The gastrointestinal tract contains trillions of microbes that are known collectively as the gut microbiome. In our bodies, there are more good bacteria than bad bacteria; our bodies are host to over 100 trillion good bacteria.¹

The species and quantity of bacteria vary greatly from person to person, and research hasn’t yet formed a clear consensus on what makes up a “healthy” microbiome.

Microbes are found all the way through the gastrointestinal tract, but most are in the large intestine or the colon.¹ The balance must be maintained between the good and bad bacteria for a healthy gut microbiome.

When the balance is off, this is referred to as dysbiosis. Dysbiosis can make you more susceptible to disease and cause many unpleasant symptoms throughout the body.

What Impacts the Gut Microbiome?

Lifestyle, environment, stress, disease and diet all have a significant impact on the gut microbiome.³ Probiotics and prebiotics are uniquely able to affect the microbiome, and we can get these from our diet or through supplements.

An unhealthy gut microbiome has been linked to a whole host of health issues such as obesity, asthma, allergies, autoimmune conditions, skin conditions and mental health issues, to name a few.¹¹ Research has shown an unhealthy gut microbiome can be responsible for or worsen symptoms of these conditions, but also that these conditions can create an unhealthy gut microbiome. 

What are Probiotics?

Probiotics are live microorganisms that offer health benefits, including helping to enhance or restore health in our gut microbiome. Probiotics add new species of good bacteria into the gut microbiome whilst feeding the existing good bacteria, allowing them to grow stronger and repopulate.

For a food to be considered “probiotic”, there must be sufficient living bacteria that survive food processing so our bodies can use the probiotic content. These live bacteria have to be the good kind that benefits human health, not pathogenic bacteria that hurt the gut microbiome.⁴

Probiotics can be found in foods in fermented foods such as kimchi, pickles and sauerkraut, some yoghurt, some cheeses and sourdough bread.⁵ They are also often added to foods like granola bars, and protein shakes. 

2 species of bacteria commonly found in foods containing probiotics or probiotic supplements are Lactobacillus and Bifidobacterium.

Lactobacillus can benefit those with lactose intolerance, and studies have shown considerable improvements in those with diarrhoea. Bifidobacterium has been shown to relieve symptoms in those with IBS.⁶

Research suggests that probiotics can be helpful for those with:

• IBS
• IBD
• Infectious diarrhoea 
• Diarrhoea caused by antibiotics
• Skin conditions
• Poor immune system
• Oral health issues
• Urinary and vaginal health issues

What are Prebiotics?

Prebiotics are non-digestible food ingredients that benefit our bodies by stimulating the growth of good bacteria and improving our health.⁷ Many prebiotics are high-fibre foods that aren’t broken down by our digestive enzymes. 

An easy way to look at it is that prebiotics is food for our gut microbes. They can eat the prebiotics, which allows them to survive and flourish. Good bacteria need to repopulate to take up room. Otherwise, the bad bacteria will repopulate, which causes dysbiosis. If they aren’t fed well, they can eat the intestinal lining, leading to inflammation.

When the gut microbes use the prebiotics, some produce short-chain fatty acids. Short-chain fatty acids are essential for the health of our body, and studies have shown they have systemic anti-inflammatory effects.⁸

Short-chain fatty acids reduce the risk of inflammation by nourishing the cells that line the gut. They have been associated with reducing risks of some types of cancer, helping the body absorb calcium and relieving digestive issues such as constipation and diarrhoea.⁹

Some great sources of prebiotics are garlic, onions, leeks, bananas, oats, cocoa and seaweed.¹⁰ Foods and supplements can contain prebiotic properties, probiotics, and many other nutrients that greatly benefit the gut microbiome. 

The Bottom Line

The role of the gut microbiome on our overall health and how to keep it functioning optimally is still a relatively new concept in science, so much more research is needed in this area.

However, we know that probiotics and prebiotics can stop us from suffering dysbiosis and that being conscious of their potential benefits can be great for our wellbeing. 

Why not try implementing some of these foods or supplements into your life and see if you can improve your health?

Related Content: The Gut Microbiome: All You Need to Know