Prebiotics: fuel for probiotics - the good bacteria in your gut

You are what you eat. The truth behind this adage lies in your gut microbiome. By now, you likely know about probiotics, the good bacteria in your gut that support digestive health, immunity and mental health.

These friendly bacteria use glucose as a source of food, but in the lower intestine where glucose is scarce, they thrive on prebiotics, a type of soluble fibre found in healthy foods.

Probiotics ferment prebiotics to use them as food. In the process, short chain fatty acids (SCFAs) are produced, which provide their own unique benefits.

The lower intestine is home to the vast majority of bacteria – both good and bad. Consuming foods rich in prebiotics helps ensure that you maintain a healthy balance of good bacteria in your lower intestine.

Low levels of good bacteria can contribute to dysbiosis – an imbalance of bad bacteria in your gut. Studies by The Chinese University of Hong Kong suggest that around 40% of the Hong Kong population have dysbiosis.

Signs you aren’t getting enough prebiotics include: issues with your gut – from pain to irregular bowel movements; poor immunity; skin problems; low energy; trouble losing weight or cravings for sugar; and mood problems.

Types of prebiotics include fructans (like inulin), fructooligosaccharides (FOS), galactooligosaccharides (GOS), resistant starches, xylooligosaccharides and pectic oligosaccharides. Prebiotics are also found naturally in breast milk, and help establish healthy levels of good bacteria in your baby’s gut. 

Benefits of prebiotics

Inulin is proven to boost the colonisation of good bacteria like lactobacilli and bifidobacteria, thereby promoting the benefits of probiotics. It also helps lower the pH of the colon – providing an optimal environment for good bacteria – which conversely is a challenging environment for bad bacteria – making it harder for them to colonise the gut.

Studies cite that consuming 5g of prebiotic GOS daily can ease symptoms of depression, but more research is needed to explore the relationship between prebiotics and mental health. It’s theorised the emotional benefits are due to the creation of neurotransmitters which regulate mood, and the production of short chain fatty acids.

When prebiotics are degraded by good bacteria, they produce short chain fatty acids as a byproduct, which provide additional benefits. 90% of the SCFAs produced by the gut microbiome are acetate, butyrate and propionate. These molecules enter the blood circulation and provide benefits to many other organs and systems. 

The benefits of SCFAs

If you’re aiming to lose weight, forget fads like slimming teas. These teas usually include a laxative called senna, which moves food through your digestive tract quickly. Though weight loss may occur, this is due to fluid loss and dehydration. Doctors have explicitly recommended against weight loss teas, labelling them ‘dangerous’. Your gut can become dependent on the teas for the signal to begin peristalsis (which moves digested food along the intestine) and stopping use can cause constipation, creating dependence on laxatives for digestion. Another risk factor for these teas is electrolyte and mineral imbalances.

Foods rich in prebiotics provide a natural, healthy solution for regulating your appetite, while simultaneously nourishing digestive health. SCFAs support weight management and metabolism, inhibiting the production and accumulation of fats. Acetate and propionate increase levels of GPL-1, which sends satiety signals, reducing appetite. SCFAs help support better cardiovascular health, regulating cholesterol levels, blood pressure and blood sugar levels.*

SCFAs help promote an optimal environment in the gut – protecting the intestinal barrier and supporting healthy bowel movements.

The liver and gut have a bi-directional relationship, and these benefits translate, improving liver health. The antioxidant properties of SCFAs protect the liver and support detox.

The brain and the gut also have a bidirectional relationship, and studies show that SCFAs help mediate the gut-brain axis, playing an important role in the function of the central nervous system. Those with depression have been shown to have lower levels of acetate and propionate, and acetate has also been shown to boost cognitive health.

SCFAs are also shown to help regulate the immunity and support respiratory health. They help white blood cells differentiate and regulate antigen-specific adaptive immunity.

Social stress can inhibit your ability to produce SCFAs – meaning in times of stress, it’s beneficial to increase your consumption of prebiotic foods and supplements. 

Sources of prebiotics

Dietary sources of prebiotics include legumes, beans, peas, barley, oats, bananas, berries, asparagus, artichokes, dandelion greens, garlic and leeks.

If you have a sensitive bowel, you might be eating a low FODMAP diet, which can help reduce digestive symptoms. Getting enough fibre on a low FODMAP diet can be challenging. Pre-biotic rich foods which have low FODMAPs include green bananas, oats, quinoa, cabbage, aubergine, kiwi and almonds.

Alternatively, you can reduce the serving size of high FODMAP foods. Low FODMAP diets are not meant to be followed forever – if you need help increasing your tolerance to FODMAPs, our naturopaths can help.

Some supplements also contain prebiotics. The Ther-biotic range by SFI Health (previously known as Klaire Labs) provide probiotics in a base of inulin – a prebiotic derived from chicory root.

These come in a range of formulas – Complete Capsule for once-daily dosing, Complete Powder which provides flexible dosing for the whole family, Baby and Women’s Formula, which provide specific support.

Synbiotics like Ther-biotic combine probiotics and prebiotics in one formula, which can help good bacteria survive stomach acidity and make it to the gut, ready to colonise.

Whole Fiber Fusion by Vital Nutrients is rich in prebiotics. It contains ingredients like chia seeds and flaxseed, which provide a source of prebiotics and feed good bacteria, while improving digestion. This formula also provides synbiotic benefits, as it contains lactobacillus probiotics. 

Interested in boosting your health with prebiotics?

Our naturopaths and naturopathic doctors are pros at using natural resources like prebiotics to boost your wellbeing.

They’ll carry out a comprehensive evaluation of your health, and if necessary they’ll refer you for testing to evaluate your gut health, which may include assessing you for dysbiosis or leaky gut.

If you have experienced digestive discomfort, unknown food allergies or intolerances could be informing your sensitivity. Testing can uncover these so that you can eliminate triggering foods from your diet.

Did you know your genes define which kind of diet would be best for you? Our DNA Diet test gives you personalised recommendations to optimise your diet based on your genetics.

Using data from your tests, your naturopath will clearly define the most beneficial intervention for you to meet your goals.

*This product is not registered under the Pharmacy and Poisons Ordinance or the Chinese Medicine Ordinance. Any claim made for it has not been subject to evaluation for such registration. This product is not intended to diagnose, treat or prevent any disease.

References
D Davani-Davari et al, Prebiotics: definition, types, sources, mechanisms and clinical applications, 2019.
CUHK, 40% of Hong Kong people show gut dysbiosis comparable to that of COVID-19 patients, 2020
J Slavin, Fiber and prebiotics: mechanisms and health benefits, 2013.
O Obasola Adebola et al, Synbiotics: the impact of potential prebiotics inulin lactulose and lactobionic acid on the survival and growth of lactobacilli probiotics, 2014.
L M Williams et al, The effects of prebiotics, synbiotics, and short chain fatty acids on respiratory tract infections and immune function: a systematic review and meta-analysis, 2021.
S Wang, Rational use of prebiotics for gut microbiota alterations: specific bacterial phylotypes and related mechanisms, 2020.
Y Yang et al, Prebiotics for depression: how does the gut microbiota play a role? 2023.
R-G Xiong et al, Health benefits and side effects of short-chain fatty acids, 2022.