Inulin – The Prebiotic Fibre for Gut Health

by Ashleigh Feltham,  Accredited Practising Dietitian and Accredited Nutritionist

The gut microbiome is a conductor of overall health. Following a diet promoting the health of gut bacteria is a smart investment for both short and long-term health and wellbeing. A key component of a healthy gut is the inclusion of adequate amounts and varieties of fibre.

Fibre is a type of carbohydrate that cannot be digested in the gut. Inulin is a type of soluble fibre that helps to create well-formed stools and normal bowel movements. Inulin is made up of multiple fructose units. Fructose is a type of short-chain carbohydrate. These fructosyl units are linked to one another by beta (2,1) bonds.


Hig fructose fruit - grapes

Inulin is also classified as prebiotic fibre. This means it is a fuel source for the health-promoting bacteria in the gut. Inulin feeds these microbes, producing a large amount of short-chain fatty acids. Short-chain fatty acids are signalling molecules that influence the health and function of your body.

Inulin prebiotic fibre is highly fermentable. It is like lollies for health-promoting microbes in the gut. Of the types of prebiotic fibre available, microbes absolutely love to use inulin as fuel.

A systematic review — a strong form of assessment of current research — showed the importance of inulin in boosting health-promoting bacteria. The researchers investigated the studies and the effect of inulin on the gut. All articles used were peer reviewed, the majority were double-blind, randomized control trials on human subjects and included a placebo control trial.

The review concluded that including 5-20g of inulin each day promoted an increase in health-promoting bacteria. Specifically, Bifidobacterium, Faecalibacterium, Anaerostipes and Lactobacillus. A less healthy bacteria called Bacteroides was found to decline with the addition of inulin in the diet.

These four types of good bacteria support many functions in the body, including optimising immune system function; roughly 70% of the immune system is found in the gut. These strains of microbes also promote healthy metabolic function as well as a healthy gut environment.

It is important to note that all forms of microbes can cause ill health in the absence of an overall balanced diet and a variety of prebiotic fibres. Therefore, a goal of 30 different plant-based foods each week is a smart lifestyle goal to promote not only an abundance of healthy bacteria but an optimal variety and balance, too.

Each pouch of South Australian Gourmet Food Company Fruit Custard with Added Fibre gives the body 11g of dietary fibre. They contain the health-promoting inulin variety. They are long-life and convenient to carry for easy access.

The Inclusion of 30 different plant-based foods each week is a healthy lifestyle habit to promote an optimal gut microbiome. Ensure that foods with added fibre contain quality prebiotic fibre. Each South Australian Gourmet Food Company Fruit Custard with Added Fibre contains 11g of prebiotic fibre in the form of inulin.

Take home message:

For optimal gut health, include the prebiotic fibre inulin to promote healthy gut microbes, which help your body to function at its best.



Le Bastard, Q., Chapelet, G., Javaudin, F. et al. The effects of inulin on gut microbial composition: a systematic review of evidence from human studies. Eur J Clin Microbiol Infect Dis 39, 403–413 (2020).