New research is shining a spotlight on the role of the gut in our health, not only for those living with Irritable Bowel Syndrome (IBS) but for the general wellbeing of all people.
The gut microbiota – what used to be called gut flora – is the population of microbes that reside in our intestines. The gut microbiota comprises of trillions of microorganisms, which includes at least a thousand different species of known bacteria. This totals a few million genes which is actually more than 100 times the human genes in the body. Just think about that for a second: you are comprised of more bacteria genes than human genes.
One-third of our gut microbiota is the same for most people, while the remaining gut bugs are specific to the individual. How on earth can our gut microbiota be so different?
Through this fast-developing area of study, we know the gut microbiota is affected by many things, including our age, diet, exercise, stress and even antibiotic therapy. It goes back as far as our mother’s microbiota and whether or not we were breastfed.
There are four main reasons it’s important to have a varied, health and balanced gut microbiota:
- It helps the body to digest certain foods that the stomach and small intestine have not been able to digest
- It aids in the production of some vitamins
- It assists us to maintain the wholeness of the intestinal mucosa
- It plays an important role in the immune system, acting like a barrier
It is vital learn how to keep your gut microbiota healthy. The role of diet – specifically prebiotics and probiotics – is part of this knowledge. For those living with IBS, a strange new term, FODMAP – Fermentable Oligo-, Di-, Mono-saccharides And Polyols – also enters the gut-health equation. Let’s try to demystify these terms.
What are prebiotics?
Prebiotics are the parts of certain foods that pass through the small intestine undigested, going on to ferment and feed beneficial gut bacteria. Although all prebiotics are fibre, not all fibre is prebiotic. For a food to be classified as a prebiotic, it must:
- Get through the really acidic gastric environment, avoid being broken down by enzymes and not be absorbed in the upper gastro-intestinal tract
- Travel to the large intestine, where it is fermented by microbiota
- Help grow or help with the activity of the microbiota, making it beneficial to human health.
Health benefits of prebiotics
Research suggests that eating prebiotics may:
- Protects the body against cancers such as colon cancer
- Reduces some risks for cardiovascular disease
- Minimise the length and severity of infectious diarrhoea
- Limiting the symptoms associated with Inflammatory bowel disease
- Makes minerals like calcium, magnesium and iron more available to the body
- Reduce risk of obesity through weight loss and improving satiety
Good food sources of prebiotics
- pulses (chickpeas, beans, lentils etc.)
- dried fruit
- whole grains
- kimchi, sauerkraut
This list has a few red lights for those with IBS, as many of these foods are high-FODMAP – specifically, cereal products like wheat and rye, pulses, garlic, onion and artichokes – which tend to produce IBS symptoms. Yet there are so many gut health benefits in eating these foods – what should you do if you have IBS?
As a dietitian, I advise IBS clients to complete a low-FODMAP elimination diet for 2-4 weeks and no more than 6 weeks, as cutting out these foods can change your microbiota. We don’t yet understand the full implications of this change to our long-term health, as it’s a topic of ongoing study, so please don’t continue with the elimination phase of the diet past the 6-week mark.
Once you have completed phase one, it is time to move to phase 2, re-challenging each type of FODMAP to work out your tolerance. Once you know how much your body can tolerate, personalise your diet and include as many of the prebiotic-rich foods as you can without developing uncomfortable symptoms. Remember that some bloating and gas is a normal part of digestion. If you can cope with 1 tablespoon of onion before IBS symptoms set in, keep that small quantity of onion in your diet. I always recommend re-challenging FODMAPs after 6-12 months, as your tolerance may change and you may be able to tolerate a whole lot more.
What are probiotics?
The word probiotic means “for life” in Latin. Probiotics are live microorganisms which, when we consume them in adequate amounts, produce a health benefit. To have a positive effect on our gut function, the probiotic must survive the acidic environment of the gut alive.
Probiotics typically assist in the breakdown of food for improved absorption, increasing the bio-availability of vitamins and minerals. There are hundreds of probiotics, however the most common are the bacteria lactobacillus and bifidacterium, which can boost the immune system.
Dietary sources of probiotics:
- sauerkraut and kimchi
- sourdough bread
- ginger beer
Greek yoghurt, small amounts of sauerkraut and kimchi, miso, tempeh, sourdough bread and some pickles are all safe to have on the low-FODMAP diet and should be included. Kefir is high FODMAP and should be avoid in the elimination phase of the diet.
Should you take a probiotic supplement?
There are many commercially available probiotic supplements. If you’re curious, try one after you’ve completed the low-FODMAP diet. I don’t recommend starting a course pf probiotic supplements when you are on elimination or during challenges, as it may cloud your results. Be sure to choose a well-known brand of probiotic supplement, and one that is relatively fresh – we need these microorganisms alive if they are going to help, so opt for refrigerated brands and check use-by or best-before dates.
It can take up to 4 weeks to see an effect from taking a probiotic supplement. If, after this time, you think it’s helping, stop taking it to gauge what happens without it. If things stay the same, it probably wasn’t doing much. However, if you experience a deterioration, the supplement may well have been helping you. Keep in mind that if one supplement brand didn’t work for you, you could try another.
What are the take home messages if you’re living with IBS?
- During the 2-4 weeks of elimination, continue to include low-FODMAP portions of prebiotic-rich foods, e.g. chickpeas, lentils, bananas, artichoke, kimchi and sauerkraut, and probiotic-rich foods, e.g. Greek yoghurt, sauerkraut, kimchi, miso, tempeh, sourdough bread, ginger beer, pickles etc.
- Once you have re-challenged FODMAPs and know your triggers, personalise your diet by including the high-FODMAP prebiotic-rich foods in quantities that your body can tolerate, e.g. garlic, onion, asparagus, artichokes, kimchi, sauerkraut, dried fruit, whole grains, larger amounts of lentils, chickpeas and other pulses such as baked beans etc., as well as probiotic-rich foods, e.g. fermented dairy and kefir.
- Re-challenge FODMAPs again in 6 months, as your tolerance may change.
- If you’re finding it hard to navigate the diet, please seek the assistance of a FODMAP-trained dietitian.
Jenna Haworth is an Accredited Practising Dietitian, with a special interest in food intolerances and the low FODMAP diet. Jenna runs a private practice from Shellharbour NSW, specialising in the management of IBS. To find out more about Jenna, visit www.thenutritioncentre.com.au or follow her on Instagram @Dietitian_Jenna or Facebook at The Nutrition Centre. Feel free to get in touch if you have any queries.
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