Gut bacteria influence everything from your immunity and weight to mood. HFG reveals what you need to know to keep your gut in great health.
What is the gut microbiome?
There are trillions of live microbes in your gut, anywhere from 500 to 1500 species, and their combination, or gut microbiome, is as unique your fingerprint. A high level of microbe diversity is considered good for gut health, with microbiome composition being influenced by age, lifestyle and what you eat.
What gut bacteria do
Gut bacteria play a vital role from birth till old age. Here’s a snapshot of what they do:
• Aid digestion
• Help with the absorption of nutrients, including calcium and magnesium
• Produce important nutrients, such as vitamin B12, needed for new cell production, and vitamin K, which is important for blood clotting and osteoporosis prevention
• Produce short-chain fatty acids (SCFAs) that protect and maintain the gut lining
• Metabolise cholesterol and bile acids
• Produce brain chemicals such as serotonin, which influence well-being
• Support immunity.
Is your gut healthy?
One of the easiest ways to tell whether your gut is functioning effectively is through the absence of uncomfortable or painful gut-related symptoms. While producing gas is a normal part of digestion, ongoing or consistent excess gas is a sign your gut is not working optimally. So, too, are bloating, cramping, diarrhoea and constipation.
If you’re experiencing any of these symptoms, make an appointment to get checked out by your GP before you make changes to your diet. If all the tests come back negative, you may have irritable bowel syndrome (IBS) and be referred to a qualified dietitian to help manage symptoms.
Should I take prebiotics, probiotics or postbiotics?
In short, including probiotics, prebiotics AND postbiotics in our diet can help promote a diverse and healthy gut microbiome.
Probiotics are live bacteria and yeasts that are good for our digestive system. They can help improve digestion, boost our immune system, and keep our gut healthy. Examples of foods that contain probiotics include yogurt, kefir, kimchi and sauerkraut.
Prebiotics are non-digestible fibres that feed the good bacteria in our gut. They can help improve the balance of bacteria in our gut and promote the growth of beneficial bacteria. Examples of foods that contain prebiotics include garlic, onion, bananas and asparagus.
Postbiotics are compounds produced by the fermentation in the gut of prebiotic and probiotic foods. They can help improve our immune system, support our gut health and reduce inflammation in our body. Examples of postbiotic-promoting foods include vegetables, fruits, legumes, wholegrain bread, nuts and seeds.
Should I ditch gluten and dairy?
For individuals with coeliac disease, removing gluten from their diet is crucial. For those with gluten sensitivity, eliminating gluten can lead to a decrease in gastrointestinal discomfort and better digestion and nutrient absorption. For gluten intolerant people without coeliac disease, gluten might not actually be the culprit. Recent research suggests that foods containing gluten may also be high in FODMAPs, which can be poorly absorbed and fermented in the large intestine, causing digestive symptoms such as bloating, gas, abdominal pain, and diarrhea. A supervised low-FODMAP diet recommended by a dietitian may help alleviate these symptoms.
For individuals with a dairy allergy, eliminating dairy products is essential. However, for those who have a lactose intolerance, avoiding dairy altogether is not necessary. Thanks to advances in food technology, food manufacturers can now remove lactose from dairy products while still retaining crucial nutrients such as protein, calcium, and B12, which are essential for our overall health and support our bones and muscles. There are now more lactose-free products available than ever, including milk, cheese and yoghurts to make it easy to make the switch.
What’s all the fuss about fibre?
A Fibre has the biggest influence on your gut microbiome, increasing the activity, number and overall health of bacteria. To stay regular, the recommended daily amount of fibre is 25g for women and 30g for men.
This adds bulk and helps push your bowel motion through the bowel. It is slowly and only partially fermented.
• Wholegrain flour and bread
• Wholegrain cereals and grains
• Wheat bran and rice bran
• Vegetable and fruit skin
This absorbs water and cholesterol, slows digestion and softens your bowel motion. It is highly fermentable.
• Psyllium husk
• Lentils and other legumes
• Vegetable and fruit flesh
This feeds the good bacteria that live in your bowel. It is completely fermented.
• Firm, slightly unripe bananas
• Beans and peas (red kidney, lima, adzuki, black eyed, chickpeas, lentils, green peas)
• Rolled oats (uncooked)
• Cooked and cooled pasta
• Cooked and cooled white and brown rice
• Cooked and cooled potatoes (in salads)
A mix of insoluble, soluble and resistant starch fibres are needed to support a healthy gut microbiome.
Increase your fibre intake gradually to allow time for your digestive system to adapt and therefore avoid bloating, wind or constipation. Add one new high-fibre food to your diet every two or three days and don’t forget to increase your water intake as this will help with digestion.
10 ways to up your intake of resistant starches
- Choose an oat-based cereal for breakfast or make your own muesli
- Add oats to home-baked goodies
- Swap out wheat flour for chickpea or lentil flour
- When served hot, swap out regular potato for sweet potato or serve regular potato cold
- Stock up on frozen green peas to add to meals easily
- Incorporate more vegies into your breakfast, lunch and dinner
- Eat more cashews, because these have more resistant starch than other nuts
- Thicken soups and stews with barley or red lentils (or both!)
- Make salads using barley as a base
- Include legumes in meals at least four times a week.
At Healthy Food Guide, we only collaborate with trusted brands. To bring you this article we have partnered with Liddell’s, for more information about their products visit liddells.com.au
Article sources and references
- Baker Institute. 2020. Dietary Fibre factsheet. Accessed December 2020https://www.baker.edu.au/-/media/documents/fact-sheets/baker-institute-factsheet-dietary-fibre.pdf
- CSIRO. 2020. Resistant starch facts. Accessed December 2020https://www.csiro.au/en/research/health-medical/nutrition/resistant-starch
- Dai et al. 2013. Probiotics and irritable bowel syndrome. World J Gast. 19(36): 5973-80.https://pubmed.ncbi.nlm.nih.gov/24106397/
- Fayet-Moore et al. 2018. Dietary Fibre Intake in Australia. Associations with Demographic, Socio-Economic, and Anthropometric Factors. Nutr 10(5): 599.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5986479/
- Harper et al. 2018. The role of bacteria, probiotics and diet in irritable bowel syndrome. Foods. 7(2): 13.https://pubmed.ncbi.nlm.nih.gov/29373532/
- Jacka et al. 2017. A randomised controlled trial of dietary improvement for adults with major depression. BMC Med. 15(1): 23.https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-017-0791-y
- Kelesidis T & Pothoulakis C. 2012. Efficacy and safety of the probiotic Saccharomyces boulardii for the prevention and therapy of gastrointestinal disorders. Ther Adv Gast. 5(2): 111-125.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3296087/
- McDonald et al. 2018. American gut: an open platform for citizen science microbiome research. mSystems. doi: 10.1128/mSystems.00031-18.https://msystems.asm.org/content/3/3/e00031-18