The more we learn about the gut microbiome, the more we realise how important it is in preventing and treating a whole host of conditions.
Once you start looking into how to boost your gut health and diversify your gut microbiome, you’ll soon see there is a lot of information out there, but it can be hard to pick through the advice to understand what’s backed by science and what is not.
Here we give you our top tips for good gut health, with links to the evidence that backs it up, so you can be confident these changes are likely to have a positive effect on your microbiome.
1. Diet
a. Plant-based variety
What: Enjoying a variety of plants in your diet – including fruit, vegetables, legumes, nuts herbs, spices and whole grains and seeds – is a fantastic way to boost your gut health. This doesn’t mean going vegetarian or vegan – it’s about adding more of these foods to your existing diet.
The science: Researchers at the American Gut Projecti found that people who ate 30 different plants a week had a healthier gut microbiome than those that ate 10. But what is it about plants that makes them gut-friendly?
Firstly, they are high in fibre, which is a main food source for many types of gut bacteria. Fibre also helps fight inflammationii. Inflammation happens when your immune system recognises something that has come into the body that needs fighting, but sometimes it fires up when there is no threat. This overreaction from the immune system over time leads to disease development. Fibre particularly boosts gut bacteria that produce chemicals called short-chain fatty acids (SCFAs), which have anti-inflammatory properties.
Secondly, some plants are rich in polyphenols (also found in green tea, dark chocolate, and red wine!). Research has found polyphenols can boost the growth of good gut bacteriaiii and suppress the growth of bad bacteriaiv.
Finally, many plants contain prebiotic (not to be confused with probiotic!) molecules, which aren’t digested at the start of the digestive tract and make their way to the bowel for digestion, where they are a food source for good gut bugs.
Don’t worry if you can’t get to 30 plants a week, which may feel like a daunting target. Adding any extra variety of plants to your diet will have a benefit.
You can read our tips for getting variety in your diet in an easy and affordable way.
b. Fermented food (probiotics)
What: You may have heard that probiotics – bacteria or yeasts that restore the natural balance of bacteria in your gut – are good for your microbiome. Examples of probiotic foods include yogurt, kefir, sauerkraut, kimchi, and kombucha, which are all rich in live bacteria.
Evidence: It’s clear that probiotics promote good bacteria in the gutv but what’s less clear is how to effectively deliver them to the bowel. Probiotics may be helpful in some cases, such as helping to ease some symptoms of irritable bowel syndrome (IBS)vi and Ulcerative Colitisvii. Evidence for their impact on people without these conditions is more limited. The NHS rightly points out that it can be hard to tell whether probiotic products actually contain the bacteria stated on the food label, contain enough bacteria to have an effect and whether the bacteria are able to survive long enough to reach your gut – all good things to consider if you choose to buy probiotic-containing food for your gut health.
2. Antibiotics and medicines
The use of (and resistance to) antibiotics is a hot topic in the science world, but for most of us we know antibiotics as an important part of treating infections, and it’s important to take them when prescribed. However, when they are used, they upset the balance in the microbiome because they can kill off both good and bad bacteria in the gutviii.
It is very important that you only take antibiotics to treat bacterial infections. The common cold, for example, is usually caused by a virus that will not respond to this medicine. If you do have to take antibiotics, you also need to check with your doctor that you are on the most narrow spectrum antibiotics as possible. This means it will only kill the bacteria that are causing you harm. It is also important to make sure you follow the dietary advice above, as this will protect the microbiome in your gut and your antibiotics will be more effective.
Many medicines that we don’t think of as antibiotics can also harm the microbiome. For example, common anti-reflux medicines, painkillers and even some anti-depressants. Check with your doctor that you are only taking the medicines you really need, and avoid taking any unnecessary medicines.
3. Lifestyle
a. Exercise
What: Exercise has a range of health benefits and one of these is improving the balance of good and bad bacteria in the gut microbiomeix.
Evidence: It’s not clear exactly how exercise boosts gut health but some theories are that it could suppress inflammation, reduce blood flow to the gut (by directing it to the muscles) or speed up the passage of food through the digestive system.
b. Sleep
What: Evidence is emerging that sleep and the microbiome are interlinked, and a good night’s sleep can boost your gut health. Similarly, poor gut health has been associated with disrupted sleep.
Evidence: Research showed the presence of more good bacteria was associated with better sleep efficiency, higher levels of an anti-inflammatory molecule (interleukin-6) and even better abstract thinking! Those with less diverse microbiomes were also found to wake more frequently after getting to sleepx.
c. Smoking
Studies have shown that people who smoke have less diverse gut bacteria, and that smoking-induced changes to the gut are similar to those seen in conditions such as inflammatory bowel disease and obesityxi.
References:
[i] McDonald D, Hyde E, Debelius JW, Morton JT, Gonzalez A, Ackermann G, Aksenov AABehsaz B, Brennan C, Chen Y, DeRight Goldasich L, Dorrestein PCDunn RR, Fahimipour AK, Gaffney J, Gilbert JAGogul G, Green JL, Hugenholtz P, Humphrey G, Huttenhower CJackson MA, Janssen S, Jeste DVJiang L, Kelley ST, Knights DKosciolek T, Ladau J, Leach J, Marotz C, Meleshko D, Melnik AVMetcalf JL, Mohimani H, Montassier ENavas-Molina J, Nguyen TTPeddada S, Pevzner PPollard KS, Rahnavard GRobbins-Pianka A, Sangwan N, Shorenstein J, Smarr LSong SJ, Spector T, Swafford AD, Thackray VG, Thompson LRTripathi A, Vázquez-Baeza Y, Vrbanac A, Wischmeyer PWolfe E, Zhu Q, , Knight R2018.American Gut: an Open Platform for Citizen Science Microbiome Research. mSystems3:10.1128/msystems.00031-18.https://doi.org/10.1128/msystems.00031-18
[ii] Portincasa, P.; Bonfrate, L.; Vacca, M.; De Angelis, M.; Farella, I.; Lanza, E.; Khalil, M.; Wang, D.Q.-H.; Sperandio, M.; Di Ciaula, A. Gut Microbiota and Short Chain Fatty Acids: Implications in Glucose Homeostasis. Int. J. Mol. Sci. 2022, 23, 1105. https://doi.org/10.3390/ijms23031105
[iii] Catalkaya G, Venema K, Lucini L, et al. Interaction of dietary polyphenols and gut microbiota: Microbial metabolism of polyphenols, influence on the gut microbiota and implications on host health. Food Frontiers. 2020; 1: 109–133. https://doi.org/10.1002/fft2.25
[iv] Plamada D, Vodnar DC. Polyphenols-Gut Microbiota Interrelationship: A Transition to a New Generation of Prebiotics. Nutrients. 2021 Dec 28;14(1):137. doi: 10.3390/nu14010137. PMID: 35011012; PMCID: PMC8747136.
[v] Markowiak P, Śliżewska K. Effects of Probiotics, Prebiotics, and Synbiotics on Human Health. Nutrients. 2017 Sep 15;9(9):1021. doi: 10.3390/nu9091021. PMID: 28914794; PMCID: PMC5622781.
[vi] https://www.nhs.uk/conditions/probiotics/
[vii] https://www.bda.uk.com/resource/probiotics.html
[viii] Langdon A, Crook N, Dantas G. The effects of antibiotics on the microbiome throughout development and alternative approaches for therapeutic modulation. Genome Med. 2016 Apr 13;8(1):39. doi: 10.1186/s13073-016-0294-z. PMID: 27074706; PMCID: PMC4831151.
[ix] Mailing, Lucy J.; Allen, Jacob M.; Buford, Thomas W.; Fields, Christopher J.; Woods, Jeffrey A. Exercise and the Gut Microbiome: A Review of the Evidence, Potential Mechanisms, and Implications for Human Health. Exercise and Sport Sciences Reviews 47(2):p 75-85, April 2019. | DOI: 10.1249/JES.0000000000000183
[x] Smith RP, Easson C, Lyle SM, Kapoor R, Donnelly CP, Davidson EJ, Parikh E, Lopez JV, Tartar JL. Gut microbiome diversity is associated with sleep physiology in humans. PLoS One. 2019 Oct 7;14(10):e0222394. doi: 10.1371/journal.pone.0222394. PMID: 31589627; PMCID: PMC6779243.
[xi] Savin Z, Kivity S, Yonath H, Yehuda S. Smoking and the intestinal microbiome. Arch Microbiol. 2018 Jul;200(5):677-684. doi: 10.1007/s00203-018-1506-2. Epub 2018 Apr 6. PMID: 29626219.