To Your Patients’ “Gut Health”: Become a Microbiome Manipulator

There’s no doubt: the gut microbiome is a hot topic in health. An increasing body of research is revealing links between gut health, diet and disease. With this in mind, are you ready to become a “microbiome manipulator,” for your patients’ good health?

We asked two leading experts our burning questions about the gut microbiome: Professor Nicholas Talley, who is a world-leading neurogastroenterologist and Pro Vice-Chancellor (Global Research) & Laureate Professor at the University of Newcastle, and Professor Mike Gidley, Director of the Centre for Nutrition and Food Sciences (CNAFS) at the University of Queensland.

Why is a healthy microbiome important?

Prof Talley says, “There’s a huge number of bacteria and other living organisms that are in the gut – and also just about everywhere in the body. We are now realising that these organisms are regulating our health, keeping us healthy – and are significantly relevant to numerous diseases.”

His key takeout for your patients: “We now know, very clearly, that the bacteria that live with us, in us and around us are absolutely essential to our survival. No bugs, and we’re not here.”

What does a healthy microbiome look like?

HotTopic2There are three factors that most people agree on,” notes Prof Gidley. “First, the microbiome should be diverse, with many different types of bacteria – the more, the better. Second, that diversity should predominantly be microbes feeding off of carbohydrates, and not feeding off proteins.

“The third is lack of pathogenic microbes, essentially gut infections which are reflective of poor gut health. If you have a poor microbiome, you are more at risk of having gut infections.”

His key takeout for your patients: “A diverse, carbohydrate-fermenting microflora is protective against pathogenic incursions.”


What do we know about the link between the gut microbiome and disease?

“Whenever you look for a correlation between features of the gut microflora and almost any aspects of human health, there tends to be some association.” says Prof Gidley.

“The effect of the microbes in our gut is not limited to our gut. We know that the microbes talk to the gut mucosa, to the nerves in the gut, and they communicate basically with the rest of the body through this mechanism.

“A significant number of gut diseases – from inflammatory bowel disease to irritable bowel syndrome to functional dyspepsia – and probably even a number of conditions like anxiety and depression – are likely linked to the bugs, the composition of the bugs, and how they talk to each other and the rest of the body”, said Prof Talley.

The key takeout for your patients: Cultivating a healthy bacteria population in our gut is critical to our overall health.

How can we help create a healthy microbiome?

HotTopic3Prof Gidley explains, “Diverse food leads to a diverse microbiome – that’s the current hypothesis. The next logical step is to connect that back to the dietary guideline advice, which is to eat a variety of foods that includes vegetables, fruits, wholegrains and other plant foods, legumes and so on.”

“Think of the large intestine as a fermentation vessel. There are bacteria there, and they have to have something to ferment. As long as you’ve got a good diet, then your bacteria will be feeding off your dietary fibre – vegetable, wholegrain and fruit fibre – because this is not digested in the small intestine.

“However, fibres have a variety of different effects – fibre ain’t fibre. Certain types of fibres are fermented rapidly, such as the soluble small sugars that are dissolved and quickly fermented; then, at the other extreme, you have woody, cellulosic tissues that are hardly fermented at all, such as sweetcorn kernels.

His key takeout for your patients: “A good healthy diet has components that have different rates of fermentation that ensure we have a 24-hour process of fermentation. You want to feed the gut bacteria in a slow, steady, drip-feed with a variety of types of fibre – from a variety of types of food.”

What are the consequences of a diet without adequate fibre?

HotTopic4Prof Gidley points out that the microbiome helps explain some of the dietary advice we’ve been giving our patients. “We’re now starting to understand what’s behind the recommendations to include a diet rich in fruit, veg and whole grains – your microbiome has a lot to say in that respect.”

“If you don’t have enough fibre getting to the large intestine, then you have primarily other food components and digestive secretions that are protein-rich, and in the absence of fibre the bacteria have to ferment protein. The same thing happens if we have too much protein compared with fibre in our diet.

“Fermenting protein without fermenting carbohydrate is commonly considered a bad thing. If you ferment protein directly, then some of the end products are toxic – which may explain the risk of colon cancer. If you have fibre being fermented at the same time, that’s not a problem, because those toxic products can be mopped up by the bacteria that grow.”

His key takeout for your patients: “The best fibre comes from whole foods, so there is no need to look for foods with added fibre. A diverse microbiome comes from diverse kinds of fibre, and the way to get that is diverse foods.”

How long does it take from changing the diet to seeing a change in our gut health?

“Imagine microbes with lives of hours to days; the population can change quickly, probably in one to three weeks,” says Prof Gidley. “The good news is, the dietary changes we make can have an effect over a manageable timeframe.”

Geraldine-GeorgeouWhat simple diet changes make a difference to the microbiome?

We asked leading Accredited Practising Dietitian Geraldine Georgeou about her top patient tips to increase the amount and diversity of fibres from food to drive a healthy microbiome.

Geraldine, author of “The Gut Foundation Cookbook” and director of Sydney’s Designer Diets clinics, was a gastroenterology dietitian at The Prince of Wales Hospital, and has amassed extensive experience in gut health over her 20+ years in dietetics.

What are the different types of fibre, and in which foods can they be found?

“There are three different types of fibre – insoluble fibre, soluble fibre and resistant starch – which can be found in a variety of foods.

Insoluble fibre is found in mixed grain bread, rice bran, vegetables, fruit, nuts and seeds. This type of fibre resists breakdown, absorbing water to soften stools and create bulk. Insoluble fibre helps to increase the rate at which bowel contents move through,” says Geraldine.

Soluble fibre can be obtained by eating legumes, pectins and guar gum. This type of fibre is broken down by bacterial enzymes and improves environment of the gut, and acts as a prebiotic. Soluble fibre provides a feeling of fullness, adding bulk to stools, controlling blood glucose and cholesterol levels and stimulating bowel-muscle contraction.

Resistant Starch can be found in grains, seeds, lentils and potatoes. This starch produces helpful fatty acids, adds bulk to stools and stimulate bowel-muscle contraction.”

How much fibre is enough? What should our patients aim for?

According to Geraldine, “The Australian Dietary Guidelines recommend adults are encouraged to consume 25 – 30 grams of fibre a day. A smaller amount is recommended for children.

“Take a look at the table below(1) and work out your average daily fibre intake – this is a good table for patients to fill out too as you can simply work out ways to increase fibre intake from their food choices.”


What are your top food tips to increase the diversity of fibre for gut health?

Geraldine outlined seven key strategies for your patients, as follows:

  1. Choose wholemeal or wholegrain breads, or try fibre-boosted white breads. Look for ‘high in fibre’ on the label.
  2. Choose a high-fibre breakfast cereal, such as wholegrain cereals and muesli, aiming for at least 2g of fibre per 30g or at least a Healthy Star Rating of 4 and above.
  3. Use wholemeal flour in cooking, and choose wholemeal pasta and brown rice rather than white.
  4. Choose fresh fruits rather than fruit juices and don’t peel fruit if it’s not necessary.
  5. Add beans, barley or other whole grains to soups, casseroles and rissoles.
  6. Don’t rely on plain lettuce-based salads for your fibre. Try cooked, cold wholegrains, and include beans or lentils, too.
  7. Cold potato has more resistant starch than when it’s first cooked, so it’s great as a cold potato salad with parsley, spring onion and olive oil vinaigrette.

What are the simplest ways to increase fibre diversity that work for your adult patients?

Geraldine says that incorporating different fibres can start with breakfast.

“Try baked beans on wholegrain toast, plus a dollop of Greek yoghurt (probiotic support), and a 1 tbsp topper of muesli/rice bran and seed. This breakfast is a great way of incorporating all three fibres and promoting healthy microbiome,” she explains.

Another suggestion? “Try a smoothie, using 300ml reduced fat milk with 1 tbsp of chia seeds, 1 tbsp of oats, ½ a banana and 1 tbsp of natural Greek yoghurt.”

1 Table figures sourced from FoodWorks 8 Professional. Australia: Xyris Software (Australia) Pty Ltd; 2015.

Click here to subscribe to Scoop on Breakfast