PREBIOTICS V PROBIOTICS

Written by Emily Hohler, BA(Oxon), dipION, Registered Nutritional Therapist and Nature Doc practitioner 

Prebiotics v probiotics

There is a growing interest in gut health and the microbiome, however navigating the world of ‘biotics’ can be confusing. Most of us are familiar with ‘antibiotics’ and ‘probiotics’. ‘Prebiotics’ are less well understood. Sourdough provides a useful analogy. The starter itself, essentially a culture of wild yeast and bacteria, represents the gut microbiome (probiotics). Flour and water provide the ‘food’ (prebiotics). The bubbling of the starter indicates fermentation, indicating that it is growing and thriving. The same goes for our gut. If you neglect your starter and don’t feed it for a long time or feed it with poor-quality flour or chlorinated water, it can develop mould or become sluggish. Neglect your gut microbiome by failing to feed it the right foods, and similarly, it can lead to an imbalance in the composition of the microbiome, otherwise known as dysbiosis. 

Probiotics: natural v supplements

We should all be eating probiotics regularly, ideally daily, to support the health of our microbiome. Rich sources include fermented foods such as sauerkraut, yoghurt, miso, kefir and some cheeses. As for probiotic supplements, there is a bewildering range on the market featuring combinations of strains and while they can be a useful addition, particularly if we have taken a course of antibiotics, it is important to be aware that their effect is transient in that they do not appear to colonise the gut. Because they are living organisms, they can also be degraded by heat, stomach acid and other environmental factors. Natural probiotics often contain a wider variety of strains and are combined with other nutrients that encourage survival and growth, so are more likely to have a beneficial effect on our health. Some probiotics also contain prebiotics and are referred to as ‘synbiotics’.

Why prebiotics matter?

 Prebiotics are indigestible fibres that feed the beneficial microorganisms in our intestines. Scientists continue to deepen our understanding of the role of prebiotics, but we do know that they help us to absorb nutrients, particularly minerals such as iron and calcium, and that they contribute to a healthy gut barrier, make our guts more resistant to infection, and more generally, help our immune system to function well. In part, this is down to the superpowers of short chain fatty acids (SCFAs), a byproduct of the fermentation process (think back to that sourdough). Unfortunately, many people in the West consume very little fibre, let alone prebiotic fibre; an average of just 20g a day. Contrast this with the Hadza tribe of Tanzania, one of the last hunter gatherer tribes of the world, who eat 100-150g of fibre a day and boast one of the most diverse microbiomes in the world, with an average of 730 bacterial species in their guts compared to 277 for the average Californian. This lack of diversity in the Western microbiome has implications not just for the health of those alive today, but, research now suggests, that of future generations.

Sources of prebiotics

 What we know to be true at a macro level – that the healthiest and most resilient ecosystems are the most diverse – is also true at the micro level of the human gut. Reduced microbial diversity has been linked to a wide range of health issues from digestive problems to metabolic disorders, autoimmune diseases and even mental health conditions. This underscores the importance of eating not just lots of plant foods, but lots of different types of plant foods. It’s not just about bacteria. Plants also supply the vitamins, minerals and antioxidants we need for key functions such as lipid metabolism to blood sugar regulation. Fibre promotes regular bowel movements. And of, course, some of them provide us with prebiotics. Legumes, whole grains, artichokes and sweet potatoes, bananas, apples, berries and pears all contain prebiotics as do onions, garlic, asparagus, artichokes, leeks and chicory root. Given what we know about the transience and fragility of shop-bought probiotics, eating prebiotic foods is arguably a more reliable way of supporting your gut health. Prebiotic supplements, meanwhile, offer stability and consistency and can easily be incorporated into your cooking without losing their benefits. And if you do consume probiotic foods, which hopefully you will be, prebiotics can amplify their benefits.

In short, think of prebiotics as fertiliser for beneficial bacteria, helping them to establish and thrive in your gut. Armed with this knowledge, we can all make mindful dietary choices and cultivate a thriving gut ecosystem that supports not only our health, but potentially that of generations to come.