So what’s the deal with pro and prebiotics?
According to Bowel Research UK, nearly three quarters of UK adults buy the same foods every week. This lack of food diversity may increase our risk of gut issues. Poor gut health can significantly impact our quality of life and yet simple dietary changes, such as changing what we routinely buy and picking some key foods, can make all the difference.
Understanding what pre- and probiotics are is a useful starting point. These gut health essentials serve distinct, yet related roles, helping to nourish and balance our digestive system.
• Probiotics are live microorganisms that we consume directly and that provide a health benefit.
• Prebiotics are the substrates, including dietary fibres and other plant components, that feed the good microbes already living in your gut and provide a health benefit.
A simple analogy is to think of your gut as a garden – probiotics represent the plants and flowers, and prebiotics are the fertiliser you feed them.
A probiotic is a live microorganism that confers a health benefit when administered in adequate amounts. Many of these live micro-organisms occur naturally in cultured or fermented foods such as yogurt, kimchi, sauerkraut, miso and kefir but they are also very popular as a supplement. They are known as ‘good’ or ‘friendly’ bacteria as they compete for space and food with less beneficial – and even harmful – microbes and prevent them from settling in the gut.
Prebiotics are non-digestible carbs. Just as their name suggests, we can’t digest them, but they’re broken down by microbes in the gut and act as fuel to nourish the microbes that live in our colon. These carbs occur naturally in the diet and are found in many foods including garlic, bananas, oats, onions and leeks.
Why it’s important to look after our gut bacteria
The microbial balance of our gut changes over time which can impact our health and wellbeing. There are several lifestyle and dietary factors that may negatively affect our gut balance, these include:
High levels of stress – this may change the number and diversity of gut bacteria, which in turn may affect your immune system
Excessive alcohol consumption – this can be inflammatory and affect the lining of our digestive system; this negatively impacts the beneficial microbes that live there
Smoking – can have a negative impact on our gut microbes as well as the other well-documented health risks it presents
Antibiotic use – although designed to fight infections, antibiotics reduce and deplete the microbes living in the gut, this can disturb the natural balance
Following a low-FODMAP diet, which reduces your intake of fermentable carbs, this can negatively affect the microbes in the gut. It is therefore important that these foods are omitted for a specified time and only under the guidance of a specialist dietitian.
So, what are the benefits?
There is still much to discover about how the microbes in our gut influence our health, although it is already well-proven that probiotics improve IBS symptoms, traveller’s diarrhoea and the duration of antibiotic associated diarrhoea.
Other potential benefits include lowering blood pressure, improvements to the immune system, the potential to improve cholesterol levels and benefits in cold or flu during stressful periods.
I’m a fan of prebiotics and dietary fibre for gut support.
Prebiotics feed the beneficial bacteria already living in your microbiome. When you support and nourish these microbes, they do a lot of the work for you. That also means you don’t need to get overly granular about which specific bacteria you’re trying to boost.
This is not to say that probiotics can’t be beneficial or that they don’t have their place. But their use is often more targeted – for example if you’ve just finished a course of antibiotics - whereas increasing fibre intake and eating a diverse range of plant foods is a solid bet for supporting gut and metabolic health across the board.
I want to leave you with these two reminders:
We already have strong evidence for what works to improve the gut. Simple dietary patterns (eat more fibre and a variety of plants), consistently applied over time.
In general, probiotic supplements are safe for healthy individuals, however those with a compromised immune system should seek advice from a specialist dietitian or GP.