Probiotics, Prebiotics & IBS


Probiotics, Prebiotics & IBS

Joanna Baker APD & RN

Your gut does more than just digest food; it also houses the trillions of healthy bacteria that make up your gut microbiome. While science is just beginning to understand the complexity of these bacteria they have already linked them to body weight, immunity, diabetes, heart disease, bowel cancer, inflammatory conditions, mental health and even sleep patterns. The more we learn, the more it becomes apparent that our gut microbiome is critical to our overall health and wellbeing.


We also know that an imbalance in gut microbiome is implicated in IBS symptoms like bloating, pain and altered bowel habits. Including some gut-healthy strategies in your IBS toolbox is an important part of both immediate symptom management and long term health and wellbeing.


Probiotics and prebiotics are two options that you might have considered to improve your gut health. But what are they and should you be taking them?


These are live organisms that when eaten in food or as a supplement set up home in your gut. The common ones that you might have seen around are lactobacillis & bifidus.


Whether or not you need probiotics is a tough question. We know that the more diverse our gut bacteria is the better it is for our bodies. We also know that our own balance of gut bacteria is influenced by our mother, our diet, our environment, our exercise patterns, as well as alcohol and medications we might be taking. Our gut microbiome is not only more individual than our fingerprints, but it’s also variable day to day and week to week. Right now science is not yet at the point of being able to accurately test our gut bacteria and tell us what specific microorganisms we need.


All this makes choosing a probiotic tablet quite difficult. What’s right for you now will be different from what right for your friend or neighbour, and may also be different from what’s right for you in six months’ time. These complications are also reflected in the research around the benefits of probiotics which tend to show that they are just as likely to do nothing or make things worse, as they are to make things better.


So, do you need a probiotic?

Maybe and maybe not, it’s hard to say and even harder to say which one. As a dietitian, my advice is to look at the types of foods that contain probiotics (e.g. tofu, tempeh, yoghurt, sourdough bread, miso, pickles and fermented foods like sauerkraut and kefir) and include low FODMAP serves of these in your regular daily plan. You might want to start by checking out this article from A Little Bit Yummy for 6 Low FODMAP Probiotic Foods


Guidelines for trialing a probiotic

If you want to try a probiotic, I recommend avoiding it in the Elimination or Challenge phase of the low FODMAP diet, unless under the guidance of a specialist dietitian. These phases of the low FODMAP diet are about finding out how your body reacts to FODMAPs in food and probiotics can skew the results. If you are past this and in the personalisation phase, you can try a probiotic to see if it helps. It’s good to choose one of the well known brands and one that is relatively fresh (we want those organisms alive if they are going to help). Probiotics may need to be taken for up to 4 weeks to see an effect. If after this time, you think they are helping, stop taking them to see what happens without them. If things stay the same, they probably weren’t doing much more than placebo, however, if things deteriorate, they were probably helping. You might like to check out this article from Diet vs Disease on The Best Probiotics For Irritable Bowel Syndrome.



Prebiotics are different from Probiotics. Prebiotics are when the food that you eat provides fuel and nourishment for the healthy bacteria that live in your gut. If you’ve ever wondered if any of these foods are high FODMAP, you’d be right. These are foods that are not digested properly in the small intestine and end up travelling to the large intestine, where the majority of our gut bacteria live. Once they arrive in the large intestine the bacteria consume them and in the process, they ferment them. It’s this fermentation that creates the gas, which is implicated in the bloating, excessive wind and cramping that is characteristic of IBS.


Foods That Contain Prebiotics

Foods that contain large amounts of prebiotics include; wheat, onion, garlic, cabbage, nuts and legumes. The low FODMAP diet does restrict a lot of prebiotic foods, and specifically for this reason. We restrict FODMAPs to get good symptom management, but the off shoot of this is that if we also restrict prebiotic foods. In turn, this limits the foods that provide fuel and nourishment to our gut bacteria. The research indicates that this does have a clinical effect, with as little as three weeks on a strict low FODMAP diet showing a reduction in gut bacteria and the diversity of gut bacteria. Unfortunately, the low FODMAP diet hasn’t been around long enough (it was first evidenced by research in 2006) for us to know the long term effects of this. But it can be expected that it could have a significant impact on long term health and wellbeing.


It’s the low amounts of prebiotics and the flow on effect to our microbiome that is the reason it is recommended to not stay on a strict low FODMAP diet for any longer than 2-6 weeks. In the long term, to ensure gut health, you want to be including regular amounts of higher prebiotic foods in your day to day meals. The Challenge phase of the low FODMAP diet will help you to identify what foods and at what serve sizes you can tolerate. For more information on the Challenge phase of the low FODMAP diet, check out this article on How to Challenge & Reintroduce FODMAPs and the The Ultimate Guide to Challenging FODMAPs.


Final thoughts

The health of your digestive tract and the bacteria that live there are vital to overall health and wellbeing. Although benefits vary, experts agree that balancing and nourishing your gut bacteria is a key tactic to managing IBS.


Joanna & Marnie are gut health expert dietitians, we can help you translate the science of probiotics and prebiotics into practical and personalised strategies that will help you achieve a happy and healthy gut. We consult privately in Melbourne’s inner South East and via Skype. To make an appointment or seek advice, you can call any of the consulting rooms directly or email us at dietitian@everydaynutrition.com.au



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Meet Joanna


Joanna is a passionate advocate, communicator and educator in the fields of gut health, nutrition and wellness.