gut health myths
  • December 12, 2022

Unpacking Gut Health Myths with Dietitian Chelsea McCallum

Today we are chatting to gut health Accredited Practicing Dietitian Chelsea McCallum. She is an online dietitian based in Brisbane […]

Today we are chatting to gut health Accredited Practicing Dietitian Chelsea McCallum. She is an online dietitian based in Brisbane Australia and founder of the IBS Relief Program – a digital solution to help IBS suffers globally.

She specialises in irritable bowel syndrome (IBS) and the Low FODMAP Diet. Today we will be chatting with her about unpacking common gut health myths we see in clinic and online.

What inspired you to be a dietitian, and who do you work with in practice?

I have always wanted to be a dietitian since high school, and this came from a love of food and cooking. Plus, I really enjoyed biology. So, these combined made dietetics a perfect choice for me. I predominantly work with clients who have IBS or other functional gut disorders such as IBDs (Crohn’s or Colitis), Coeliac Disease or other similar conditions


What got you into working in the gut health space? 

Chelsea:  I have my own gut issues which came up during my studies at university and we did touch on this at uni but only spent about 20-40 minutes on it. Because we didn’t focus on it much, it was pushed out of my mind but as I got older and my symptoms got worse, I realised that I needed to do something for myself to improve this. Plus, I noticed so many of the clients I was seeing also had gut issues (even the ones coming in for other reasons like diabetes). I realised that people really needed more help in this field, so I decided to go into it and have never looked back.



What are the most common gut health myths you see online?

Going completely gluten free or dairy free is the biggest one. Or in general, any blanket advice that isn’t tailored that says you need to cut out an entire food group or specific food/s if you have a certain condition such as IBS.

This is unless it has been advised to you personally by your health practitioner that knows you and your symptoms.


Another one we see come up a lot is SIBO (Small Intestinal Bacterial Overgrowth). What are your thoughts on this?

It is an interesting space, and more and more research and information is coming out about bacteria that can migrate from the large intestine to the small intestine.

  • This can cause some really similar symptoms to IBS like bloating, cramping, diahorrea, abdominal pain and constipation.
  • However, unfortunately it is really hard to diagnose and treat.
  • So, it definitely isn’t a myth and does exist, but is really hard to actually diagnose.
  • It is a route I typically go down with patients who present with IBS symptoms, but typical interventions haven’t worked.

Kiah: I think a big thing is that whilst it isn’t a myth, you see a lot of alternative health practitioners diagnosing it without going through the whole formal testing. Plus, they often may also put patients on a strict elimination diet that doesn’t have any research behind it.

I have seen this a bit – particularly in cases where the client doesn’t have access to do the SIBO breath test. There is three main ways to treat SIBO – antibiotics, herbal microbials and the elemental diet. But the biggest thing people need to know is that you can’t treat SIBO with diet alone (except for the elemental diet). Diet therapy is more used alongside to help treat symptoms.


What are your thoughts on food intolerance testing? Because we see so many different ones online and in clinic. What are evidenced based, and which aren’t?

There are so many out there now. You can Google “food intolerance testing” and hundreds will come up.

  • They often use a skin prick or a saliva, hair or blood sample.
  • Unfortunately, there isn’t much research behind these, and they are testing for antibodies which should be present in our bodies anyway.
  • Often you will see that the foods you eat regularly are the ones which come up on the intolerance list and this is because they are in your system during the time of testing.
  • They are also usually quite expensive.
  • The best way to determine a food intolerance is to do an elimination diet followed by a food reintroduction phase (similar to the Low FODMAP Diet).

Are there any food intolerance tests that are real?

No, the only legit way is to do the elimination/reintroduction diets. However, allergies are very different and need to be diagnosed with a doctor.

I always reinforce with my clients that it isn’t their fault if they have fallen for a food intolerance test as we only know they aren’t legitimate because of our clinical training.


Can you tell us a bit about how disordered eating affects our gut function or causes stomach issues?

There are so many types of eating disorders and each manifest in different digestive symptoms.

  • If someone is undernourished – they often don’t have the energy to process food correctly through their digestive system which can cause digestion to slow down and lead to constipation, bloating and discomfort.
  • The large volumes of food consumed in binge eating can put distress on the digestive system also. Plus, they could be consuming large amounts of foods high in FODMAPs or other things that can cause some other symptoms a few hours after a binge like bloating, pain, diahorrea.

Meg: On the note of undernourishment causing gut issues, I’ve definitely had at least three clients recently who have come to me with gut issues which have been resolved with fuelling properly – so eating enough food. Chronic under-fuelling can even happen without them noticing or doing it intentionally.

Kiah: It is important to know that when you are starting your recovery journey, it is normal to notice a lot more gut discomfort as your gut is adjusting and getting used to it, but these do resolve over time and cutting foods out to try an resolve them can just do more harm than good. Instead, it is a good idea to work on relieving your gut symptoms secondary to re-nourishing your body.

Chelsea: Definitely, because you need to be consuming enough energy to keep your digestion going. You are essentially retraining your gut to get going again and relearn how to process larger volumes of food or more regular meals.


Another thing we see often is people following the Low FODMAP Diet on their own or as advised by their doctor or naturopath. However, they might have some disordered eating or restrictive eating tendencies as well. We know the Low FODMAP Diet is quite restrictive, so for someone with gut issues, what are some other options they could try without following such a strict diet?

Great question, but first I’d like to unpack what the Low FODMAP Diet actually is for some background.

  • FODMAP is an acronym for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols (you don’t need to know this).
  • These are types of carbohydrates we find in all sorts of foods – even things like fruits and veg which are part of a balanced diet.
  • However, they can cause some unpleasant symptoms in some people when you consume them as they rapidly draw fluid into the bowel and ferment which causes gas.
  • As dietitians we use the Low FODMAP Diet to relieve symptoms and diagnose food intolerances by reintroducing the FODMAP foods back in and seeing which ones trigger your gut and in how much.
  • However, the diet requires you to have to remove quite a lot of foods.

Instead of going straight into this diet, there are a few other things we can look at first, for instance:

  • Are you eating really fast or not chewing your food well enough?
  • We can modify the amount or types of fibre you are consuming
  • Modify toileting patterns/behaviours
  • There is also a gentle approach to the Low FODMAP diet which is far less restrictive

But, if you have been recommended to go on the Low FODMAP Diet, it is so important you do it alongside the guidance of a dietitian (regardless of if you have a history of disordered eating).



What are the long-term effects on the gut of following a restrictive diet – including the Low FODMAP Diet?

We know that every mouthful of food you consume can change the composition of your gut bacteria – even within a 48-hour period. So, you can imagine the change that can happen when you cut foods out for 2-6 week like on the Low FODMAP Diet. Or some people who haven’t had the appropriate guidance even follow this diet for months and years.

  • Cutting out foods can significantly reduce the diversity of your gut bacteria.
  • High FODMAP foods such as onion and garlic aren’t actually bad for you – in fact, they are great for your gut health BUT they can just cause some uncomfortable side-effects for some people when we digest them
  • It can also limit your social life as its harder to eat out
  • It can also create fears around foods

Can you tell us a bit about how the gut-brain axis works and what it is?

The gut-brain axis is a huge connection system between your gut and the brain and IBS is often as a result of a miscommunication between these two organs.

  • Stress we experience in the brain, can often translate into gut symptoms – for example, if you have ever been really stressed/nervous about an exam and felt a sudden urge to use the bathroom
  • So managing stress can play a big role in managing IBS – its not just food that impacts IBS


There are so many supplements for gut health being promoted and we wanted to get your thoughts on a few and if they are legit?


This can actually be quite beneficial. It can help fuel the cells that line your intestines and reduce inflammation.

  • However, the clinical dose that has been found to be beneficial is 5g three times per day which is a lot.
  • If you look at a lot of the supplements containing L-glutamine out there, the dose is generally much lower than that.
  • Plus, research suggests that it is likely only beneficial for diahorrea predominant IBS.
  • So whilst it can be helpful, it is very expensive and there is a lot of other things that you can do.



Chelsea: Looking at the ingredients list, there are so many things listed and half of them I’m not even sure of what they are/do. What I do know is:

  • Many of the ingredients are untested from a FODMAP perspective
  • Some ingredients may actually be doing more harm than good
  • There are very few ingredients that are evidence-based to actually improve gut function such as prebiotics, but you can get prebiotics through so many foods such as oats and asparagus which you may already be consuming anyway and are so much cheaper
  • It is also very expensive

Meg: How can people know if the supplement you are taking is actually helping or if it is just a placebo effect?

Chelsea: It’s really hard to know.

Meg: One thing we often recommend to clients is to just start with one change at a time to test if something works for you (first make sure it is safe and ideally evidence-based) and not making any other diet/lifestyle changes at the same time.

Kiah: Try this for a period like a month and if your symptoms improve – great, keep it up. But if not, then it likely isn’t working for you.

Chelsea: I 100% agree with this. If you’re curious about a supplement, try it (exactly how you mentioned before) and monitor how you feel while taking it. Then stop it and see how you feel without it.

Kiah: It is probably also a good idea to make your own symptom evaluation form and assessing it over the course of making these changes as it’s hard to remember how you were feeling even a week ago.

Meg: For gut health, supplements are also generally last point of call after we have tried all other avenues.


Prebiotic powders

This is a common one you’ll find on their own or in other supplements.

  • It is important to look out for them as some (e.g. inulin and chicory root) are quite high FODMAP and may do certain people more harm than good
  • PHGG (partially hydrolysed guar gum) can be much more tolerable for people like those with IBS
  • Although they have some great evidence baking them up, they may not actually be necessary, and it is worthwhile looking at your diet first.



  • With my clients, if they are going to go down the low FODMAP route, I never recommend a probiotic until this process has been completed.
  • I also always make sure if I am going to recommend a probiotic, that it is a specific strain/dosage. Probiotics are only ever the icing on the cake and only worthwhile if you are taking the specific strain/dose for your symptoms.
  • You also need to be taking them consistently each day to work.
  • Including more probiotic foods in your diet may be cheaper, more enjoyable, and more sustainable. Some probiotic rich foods include yoghurt, kefir, miso paste, kimchi, and sauerkraut.

What is something that you wish everyone knew about gut health?

I want you to keep in mind that with every mouthful you take, you can change your gut microbiome. If you want good gut heath, you should be striving for diversity in your diet.

  • One of our biggest gut studies to date found that those who had larger diversity of plant-based foods in their diet, had better gut health.
  • Change up the fruits and veg you eat each week.
  • Include nuts and seeds, legumes and wholegrains.
  • Use different herbs and spices.


Where Can We Find You?

I share a lot of free advice on my Instagram – @IBS_dietitian. You can also find me on TikTok under the same handle and get to know me a bit better.




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