Diet Tips:Evidence for the use of the Low FODMAP Diet in Children

By Marina Iacovou (PhD Candidate & Accredited Practising – Paediatric Dietitian) and Peta Hill (Accredited Practising - Paediatric Dietitian)

 Until now, dietary studies in children with IBS have assessed the effect of just one or two of the common FODMAP sugars, for example lactose, fructose and sorbitol.  A recent dietary study in children, however, has updated this literature by looking at the low FODMAP diet as a whole. 

This study was conducted by a team in the US. Our Monash team assisted to design the low FODMAP diet.  Researchers compared the typical American childhood diet (moderately high in FODMAPs) with a low FODMAP diet in children with IBS, who were aged between 7 and 17 years.

Researchers found that after just two days children experienced less abdominal pain on the low FODMAP diet, compared to when they ate the higher FODMAP diet.

Whilst a lot of research supports the use of a low FODMAP diet in adults with IBS, very little research has been done in children.  This latest study is promising, suggesting a low FODMAP diet may improve IBS symptom control in children,  but more research is needed to confirm these findings.

If you suspect your child has IBS, it is important that this is properly diagnosed by a doctor. You can read more about IBS in children in our recent blog post 

Diet Tips:Are gluten-free foods actually better for you?

Journal review by Shirley Webber (Research dietitian)

The gluten-free diet has been getting a lot of attention for a number of years now. However, there is still some confusion about whether or not this is actually a healthy diet.

A gluten-free diet restricts wheat, barley, rye and oats. Following this diet is essential for those who are diagnosed with coeliac disease. For this small portion of the population, gluten can be damaging to the gastrointestinal tract. 

There are many other people following a gluten-free diet, whether it be due to suspected sensitivity to gluten, or just because they think it is a healthier way to eat. Studies have shown that gluten intolerance without coeliac disease is rare, so for many people following a gluten-free diet for other reasons, what impact does choosing gluten-free products have on their nutritional status?

A study by researchers from the University of Sydney recently considered the nutrient differences of major gluten containing food groups which included: dry plain pasta, breads, and ready-to-eat cereals. Comparisons were made by analysing the nutrition information panel on gluten-free products (those stating on the packaging that it is gluten-free certified) and gluten containing foods in this category. Nutrients were also compared using the Health Star Rating - a nutrient profiling initiative implemented by the Australian Government. 

Analysis of the three food categories showed that there was, in fact, a very similar nutritional profile for both the gluten-free and gluten containing foods, however, with one notable difference in the protein levels: gluten-free foods contained consistently less protein than gluten containing foods, in particular in pasta and bread. There was also variation in the fibre content of gluten versus gluten-free foods.

This study also considered discretionary foods which cover: cereal bars, cake mixes/cakes, sweet biscuits, ice cream, corn and potato chips, cured meats, sausages and hot dogs, and sugar based confectioneries. For four of these discretionary foods (cereal bars, cake mixes/cakes, sweet biscuits, and cured meats, sausages and hot dogs), the Health Star Rating did not change for gluten versus gluten-free products. In three of the categories (ice cream, corn and potato chips, and sugar based confectioneries) the total energy density was lower in gluten-free products than in gluten containing products. Despite slightly better nutritional quality in gluten-free options, overall discretionary foods are all high in sodium, saturated fat, and sugar.

This study highlighted that gluten-free doesn't mean healthier, particularly when looking at some commonly used cereals, pastas, and bread, which make up a big component of the Australian and western diet. More research needs to be conducted to assess the vitamin and mineral differences of these gluten versus gluten-free products.

Wu, J. H. Y., et al. (2015). “Are gluten-free foods healthier than non-gluten-free foods? An evaluation of supermarket products in Australia.” British Journal of Nutrition 114: 448-454.
 

Diet Tips:The facts about glucose and fructose

By Dr Jaci Barrett (APD) and Caroline Tuck (APD)

Early research demonstrated that if you add glucose sugar to fructose sugar, fructose is better absorbed. This is because there are two ways that fructose is absorbed, firstly when it is absorbed slowly on its own, and secondly when it is absorbed in combination with glucose. 

Many people do not have a great ability to use the first pathway, where fructose is absorbed on its own, and this can change over time. This causes fructose to be poorly absorbed, and in IBS, cause symptoms of bloating, abdominal pain and possibly diarrhoea. The second pathway, where fructose is absorbed together with glucose, is much more efficient and works well in the vast majority of people.

We therefore test foods for their level of fructose and glucose, and only foods that contain levels of fructose higher than glucose, are considered high fructose, and avoided as part of the low FODMAP diet.

Studies, therefore, looked at whether you could add glucose to fructose so that the sugar was absorbed better - however, few studies investigated if symptoms could be improved. 

Recently, we have investigated if adding glucose to pure sugar solutions and to whole foods as we eat them in a typical diet can improve absorption and symptoms, but the outcome is not promising. Symptoms were not improved when glucose was added to fructose, and glucose makes no difference to fructans, such as in onions and wheat.

So, don’t bother adding glucose. It is unlikely to improve your symptoms and is only increasing your overall intake of sugar which is not a great idea. Just choose lower fructose foods as alternatives.
 

Diet Tips:Research update: long-term improvement in symptoms of IBS and IBD patients treated with a low FODMAP diet- A retrospective Study

By Lyndal McNamara (APD)

Background

New research about the long-term effectiveness of a low-FODMAP diet to reduce the symptoms of irritable bowel syndrome (IBS) has just been published! This retrospective study provides data regarding the longest follow up to date of patients with IBS (some of which also had IBD) using the low FODMAP diet approach. One hundred and eighty patients were included in the study. All patients had been assessed by a gastroenterologist and previously received dietary education from a dietitian regarding a low FODMAP diet. Participants were surveyed to collect information about the effectiveness of the diet, symptoms, adherence to the diet, their satisfaction with dietary treatment, disease activity, changes in stool type and quality of life over an average follow-up time of 16 months.

Results

Symptoms:

The study found that 86% of patients had a significant improvement in their IBS symptoms on a low-FODMAP diet, with the greatest relief in symptoms of bloating and abdominal pain. Overall, stool form normalised with a low FODMAP diet in the majority of patients.

Adherence and satisfaction with the diet:

Eighty four percent of patients had expanded their low FODMAP diet at follow up, where some higher FODMAP foods had been re-introduced after the identification of trigger FODMAP foods. The most common foods not reintroduced by participants were wheat, onion and lactose containing products. Despite the fact that the vast majority were following a very relaxed version of the low FODMAP diet, they still reported satisfaction with the treatment and good symptom control.

IBS severity and quality of life:

Most patients reported good quality of life and only mild-moderate IBS severity at follow up. Furthermore, 37% of IBS patients who started the trial with more severe IBS (type B, C or D in graphs below) tended towards a milder IBS (type A) at follow-up. A similar effect was noted in the group with IBS in the setting of IBD.

Study Limitations:

A major limitation of this study was that it was conducted retrospectively, meaning that the results rely on the patients’ memory and recall of events, which introduces a potential source of error. A large percentage of patients (48%) invited to take part in the study also declined to participate. This introduces a type of bias known as selection bias, meaning that those who agreed to participate may be more likely to have had a positive experience with the diet being tested. Additionally, the researchers used tools that were not validated, such as the IBS severity graphs shown in the above figures. As these are not validated, they have not been tested for their accuracy and cannot be relied upon to form firm conclusions.

Take home messages:

·         This is the first study to demonstrate the long-term effectiveness of a low-FODMAP diet for improved symptom management in IBS (alone or with coexisting IBD) patients

·         This study also supports the importance of the reintroduction phase of the diet and demonstrates that for most patients, symptom management remains satisfactory on a modified low FODMAP diet in the long-term (where some high FODMAP foods have been successfully reintroduced)

·         When looking at research studies, the tools used should be validated, and if not, outcomes should be read with caution

·         This type of retrospective study has several important limitations that need to be considered

Larger, prospective trails are now required to further investigate the long-term effectiveness and determine other effects of a low FODMAP diet in IBS and IBD patients, particularly any negative effect on the gut microbiota

1.    Maagaard L, Ankersen DV, Végh Z, Burisch J, Jensen L, Pedersen N, et al. Follow-up of patients with functional bowel symptoms treated with a low FODMAP diet. World Journal of Gastroenterology. 2016 Apr 21;22(15):4009-19.

Diet Tips:NEW PUBLICATION ALERT: Consistent prebiotic effect on gut microbiota with altered FODMAP intake in patients with Crohn’s disease: a randomised, controlled cross-over trial of well-defined diets

By CK Yao (Accredited Practising Dietitian, PhD candidate)

Research by our team has recently identified that a reduction in FODMAP intake in individuals with Crohn’s disease who were in remission produced significant changes in the gut bacteria, particularly selected species with beneficial roles in gut health.

The effectiveness of a low FODMAP diet therapy in inflammatory bowel disease (IBD) had only been explored in a group of patients with IBS-like symptoms and inactive IBD. Considerable improvement in symptoms occurred in > 50% patients after 6 weeks of the diet. However, it is not known whether a low FODMAP diet there may be potential negative changes as seen in a recent study in IBS. An ‘imbalance’ in gut bacteria may already be occurring in some individuals with inflammatory bowel disease.

We recently studied the habitual FODMAP intake and gut bacteria of 8 participants with stable Crohn’s disease and the effects of altering their diets. They were fed diets containing either low FODMAP or a ‘typical Australian’ diet (see sample meal plan) for 3 weeks, followed by a 3-week break before crossing over to the other diet. Daily gut symptoms were measured as well as changes in stool bacteria during both dietary periods.

Sample meal plan	Typical Australian diet	Low FODMAP
Breakfast	Honey quick oats or wheat flakes with dried fruit cereal with ½ cup lactose-free milk Packaged peaches	Brown sugar and cinnamon quick oats or rice bubbles with ½ cup lactose-free milk 2 kiwi fruit
Morning tea	Lactose-free yoghurt 2 rye vita crackers with cheese	Lactose-free yoghurt 2 rice cakes with cheese
Lunch	Wheat sandwich Vegetable fritata Apple juice	Spelt sandwich Low FODMAP vegetable frittata Cordial
Afternoon tea	Pear 2 chocolate biscuits	Banana 2 gluten-free chocolate biscuits
Dinner	Braised lamb shanks with vegetables Salmon and vegetable couscous	Braised lamb shanks with low FODMAP vegetables Salmon with low FODMAP vegetables and quinoa
Supper	Apple sorbet	Raspberry sorbet

Study findings:

•       When on a typical Australian diet, there was a significant increase in beneficial bacteria associated with favourable health outcomes compared to a low FODMAP diet, consistent with a ‘prebiotic’ effect.
•       However, overall symptoms, abdominal pain, bloating and excess flatulence were almost doubled than symptoms on a low FODMAP diet.
• Interestingly, the habitual FODMAP intake in participants with Crohn’s disease was low, similar to levels on a low FODMAP diet. Not surprisingly, the low FODMAP diet did not improve the severity of gut symptoms compared to symptoms on their habitual diet.  

Take home messages:  A high FODMAP diet may produce beneficial prebiotic effects for gut health in Crohn’s disease. It suggests that trialling this diet during periods of active inflammation may not necessarily be ideal for the large bowel.  On the contrary, a low FODMAP diet may be beneficial in reducing residual IBS-like symptoms in individuals with inactive Crohn’s disease.  A specialist gastrointestinal dietitian will be able to advise on finding a balance between consuming adequate prebiotic FODMAPs and maintaining good symptom control.

Read the full article here.

 

Diet Tips:A1 vs A2 milk – What’s the big deal?

By Shirley Webber

With the milk industry in the limelight at the moment many people are asking questions about what we are actually consuming. One questions that we often get is “what is the difference between A1 and A2 milk?”

The Monash University team are conducting a study at the moment looking into the effects of these two different milks and what effects A1 vs A2 milks may have on gut transit time, behavioural/psychological health and gastrointestinal symptoms.

So what’s the difference?

A1 and A2 are two proteins that are part of the casein proteins found in dairy products and we refer to these as beta-casein A1 and beta-casein A2.

The image below shows the composition of 1 cup of milk:

 

As you can see from the image above one cup of milk contains water, lactose, fat, minerals and protein. Within the protein we find casein and whey. There are various types of casein with beta-casein making up 2-3 grams of milk solids.

These beta-caseins are produced by different types of cows.

Interesting fact: beta-casein A2 is the original beta-casein produced in cow’s milk. A natural mutation over a number of centuries occurred where cattle began to also produce A1 beta-casein, affecting mainly Holstein cows (cattle from European origin).

The image below show the types of cattle used in milking and the A1 vs A2 beta-caseins that they produce.

Holstein cow’s milk =  1:1 A1 & A2 milk beta-casein	Guernsey or Jersey cow’s milk = high % in beta-casein A2	Goats, water buffalo, sheep, cattle from Asian origin and human breast milk = proteins similar to A2

Let’s get into a little more science. A1 and A2 beta casein proteins are made up of 209 amino acid chains. There is only one amino acid difference between the A1 amino acid strand compared to the A2 amino acid strand. This very small structural difference results in a big difference in the way the protein breaks down and is digested in our gut.

When the A1 amino acid chain breaks down it produces a peptide called BCM-7. BCM-7 (beta-casein morphin) is an opioid-like compound. In the human body, BCM-7 has been shown to slow down gut transit time (slows transport of food / digestion throughout the body) therefore can cause a change in bowel function, influence gut bacteria and inflammation in the gut. It is thought these changes can mean some individuals poorly tolerate milk.

There have been many animal studies conducted in this area but more investigation needs to be conducted to investigate what effects these different milk proteins has in humans.

The major point to make is that BCM-7 production does not occur after we consume the A2 beta-casein. So choosing A2 beta casein rich milk products may help some individuals.

For our research investigating the different effects of A1 vs A2 beta-casein milk we are looking for healthy and IBS constipation predominant volunteers to help shine some light onto this topic.

Healthy volunteers:	IBS
Age between 18 – 60 years      Live in Melbourne      Have no known gastrointestinal conditions	Age between 18 – 60 years      Living in Melbourne      Have non-diarrhoea predominant Irritable Bowel Syndrome (IBS)      Do not have any other gastrointestinal disease (eg. Coeliac disease, Crohns disease, Ulcerative Colitis)

What do you get?

We will be providing our participants with all milk that is to be consumed during two intervention periods of this study (A1/A1 and A2/A2 milks) as well as providing our participants with cheese. You get to have full access to a dietitian to assist you throughout the study and a free consultation at the conclusion of your participation.

What are we asking of participants?

To follow a dairy free diet with the exception of the milk and cheese that we will be providing. Be able to attend 9 consultations at the Alfred Hospital over 12 weeks of doing this study. Also be willing to give blood and small faecal samples.

Find out more about the study here. 

 

Diet Tips: RESEARCH UPDATE: How important is diagnosis of Fructose malabsorption in the FODMAP approach?

By Lyndal McNamara and Dr Jaci Barrett

Background-

New research regarding breath testing and its use to diagnose fructose malabsorption in IBS has just been published. Researchers examined existing data from several prospective clinical trials involving two groups of IBS patients to see if fructose breath test results were the same when repeated over time.1  The studies also investigated reporting of gastrointestinal symptoms during fructose breath testing and the relationship between test outcome (‘positive’ or ‘negative’ for fructose malabsorption) and the experience of symptoms.1

Study 1 - 41 IBS patients - two fructose breath tests performed, with the second test completed ≥2 weeks after the first

Study 2 - 36 IBS patients - completed a single fructose breath test and kept gastrointestinal symptom diaries the day before and the day of the test

Patients in both studies followed a diet low in fibre and FODMAPs for 24 hours and were required to fast overnight prior to each breath test. Participants consumed a drink containing 35g of fructose in 200ml of water for each test and breath samples were collected every 15 or 20 minutes for up to four hours.

Results-

Study 1 – is a fructose breath test result reproducible?

Major findings

• 30% of participants, positive for fructose malabsorption in their first breath test, tested negative on the subsequent test ≥2 weeks later
• The was no relationship between the amount of breath hydrogen produced in the first and second fructose breath tests

Study limitations-

• Some study 1 participants had their second breath test performed >19 weeks after the first. This relatively long period of time between tests means that changes in diet or medications may have affected gut bacterial populations and therefore influenced the results.
• This study included a small number of participants and retrospectively analysed data from existing studies. A larger, prospective study that collects data over a longer test period would be useful to further validate these findings.
• 
  

Study 2 – are symptoms on a breath test related to breath hydrogen response?

Major findings

• Those who tested ‘positive’ for fructose malabsorption were more likely to report symptoms during a fructose breath test than those who tested ‘negative’
• This was NOT significant when test day symptom scores were adjusted to account for the participants’ usual level of symptoms (pre-test day symptom scores)

Study limitations-

• Gastrointestinal symptom data from study 2 was only collected during the breath-testing period and not the remainder of the day, so may not have captured participants who had a delayed symptom response.

Further data-

In 2013, a group of researchers in the UK conducted a study looking at the effects of fructose in the gut.2 They were examining the osmotic effect of fructose (how much water fructose moves through the gut) and did this using superior MRI technology. They demonstrated some very interesting findings:

• Fructose has an osmotic effect, delivering water through the small intestine
• Fructose has this effect regardless of whether the person has a positive or negative fructose breath test
• The authors conclude – fructose has an osmotic effect and this does not depend on breath test outcomes
• Clinical significance – a fructose breath test is not helpful in identifying fructose as a trigger.

This figure demonstrates the increase in small bowel water content (SBWC) seen on consumption of fructose in individuals with a positive fructose breath test (blue) and a negative fructose breath test (red).2 You can see there is no difference. Fructose increases SBWC regardless of breath test outcomes.

Take home messages-

• Fructose breath test results are not reproducible, i.e. you can have a positive breath test one day, and can have a negative breath test just weeks later
• There seems to be a poor correlation between fructose breath test outcome (i.e. a ‘positive’ or ‘negative’ result for malabsorption) and the experience of symptoms in individuals with IBS
• Fructose can contribute to symptoms regardless of whether a breath test is positive or negative
• The results of this and previous research DO NOT support the use of routine fructose breath tests for the diagnosis of fructose malabsorption or to guide management in people with IBS.

References:

1. Yao CK, Tuck C, Barrett J, Canale K, Philpott H, Gibson P. Reproducibility of lactulose and fructose breath hydrogen testing and impact on clinical utility. Journal of Nutrition & Intermediary Metabolism. 4:29.
2. Murray K, Wilkinson-Smith V, Hoad C, Costigan C, Cox E, Lam C, et al. Differential effects of FODMAPs (fermentable oligo-, di-, mono-saccharides and polyols) on small and large intestinal contents in healthy subjects shown by MRI. The American journal of gastroenterology. 2014;109(1):110-9.