We’re wising up to gut health. There’s growing recognition of the amazing impact the gut has on overall health, and the role diet and other environmental factors can have in influencing digestive health. In short: it pays to be nice to your gut.

Gut health 101

And there’s good reason to do so. 100 trillion reasons, in fact. That’s the approximate number of microorganisms in the gastrointestinal tract of a human, divided up into several hundred species, with thousands of varieties possible between individuals. These microbial populations need to be kept in balance, as any upset can influence broader wellbeing.

These gut microbes produce compounds that have multiple benefits for our health. Some of these compounds are called “short chain fatty acids” (not the name of the latest indie band), which are produced by fermentation of dietary fibre in the large intestine.

The short chain fatty acids provide energy for the intestinal cells and good gut bacteria. It’s important to have a healthy intestinal lining, as this helps prevent harmful bacteria from entering the tissues and blood stream. Gut bacteria can also produce important vitamins, such as vitamin B12, vitamin K and thiamine.

Eating for good gut health

And this is where the benefits of a healthy diet come in, like including fibre as this helps to feed the gut bacteria, so it can produce the short chain fatty acids. The large intestine specifically needs “prebiotic fibre”, which can be found in certain foods such as:

• Fermented foods – kefir, sauerkraut, kimchi, miso, tempe, kombucha
• Oats, barley, rye
• Vegetables- asparagus, leek, onions, garlic, sweet corn
• Fruit- apples (pectin), unripe bananas, nectarines, watermelon, dried fruit
• Legumes, lentils
• Cashew, pistachio nuts
• Cooked and then left to cool potatoes/rice/pasta. Cooking and cooling of the food changes the composition of the starch causing it to become resistant to digestion. It then passes to the large intestine where gut bacteria can ferment it^[1,2,3].
• Conversely, having too many processed foods high in sugar and poor-quality fats and alcohol may have negative effects on gut bacteria^[3,4].

Stress and the gut brain axis

There are other lifestyle factors, such as stress, that can influence our gut microbiome. We know the gut and the brain talk to each other via the gut brain axis (aka the vagal nerve). This includes signals between the central nervous system (brain and spinal cord nerves) and the enteric nervous system (nerves of the digestive system).

Stress can alter the composition of bacteria in your gut^[3,5] so, consider incorporating practices, such as mindfulness and mediation, into your lifestyle to help manage stress.

Exercise and gut health

Exercise can have a positive impact on gut health^[3,5] and is also beneficial for mental health. This is highlighted by a recent study1that showed an increase in the diversity of gut bacteria in professional athletes, in response to exercise and a healthy diet. It’s recommended that you do at least 30 minutes of moderate exercise every day, if you can^[3].

The impact of smoking on gut health

Smoking can have adverse effects on gut bacteria^[6], which is just another good reason to stay away from the sticks.

While we’re still gaining an understanding of the full extent of the gut’s capabilities, we do know that leading a healthy lifestyle through keeping active, managing stress, looking after our mental health and following a healthy diet can go a long way to looking after our gut bacteria, and consequently our general health.

References:

1. https://www.csiro.au/en/Research/BF/Areas/Nutrition-and-health/Nutrition-and-gut-health/Resistant-starch
2. Tanja V. Maier , Marianna Lucio , Lang Ho Lee , Nathan C. VerBerkmoes , Colin J. Brislawn , Jörg Bernhardt , Regina Lamendella , Jason E. McDermott , Nathalie Bergeron , Silke S. Heinzmann , James T. Morton , Antonio González , Gail Ackermann , Rob Knight , Katharina Riedel , Ronald M. Krauss , Philippe Schmitt-Kopplin , and Janet K. Jansson, Impact of Dietary Resistant Starch on the Human Gut Microbiome, Metaproteome, and Metabolome, 2017, doi:10.1128/mBio.01343-17, https://journals.asm.org/doi/abs/10.1128/mBio.01343-17
3. Conlon MA, Bird AR. The impact of diet and lifestyle on gut microbiota and human health. Nutrients. 2014;7(1):17-44. Published 2014 Dec 24. doi:10.3390/nu7010017
4. Engen PA, Green SJ, Voigt RM, Forsyth CB, Keshavarzian A. The Gastrointestinal Microbiome: Alcohol Effects on the Composition of Intestinal Microbiota. Alcohol Res. 2015;37(2):223-236.
5. Clarke SF, Murphy EF, O'Sullivan O, et al, Exercise and associated dietary extremes impact on gut microbial diversity, Gut 2014;63:1913-1920.
6. Conlon MA, Bird AR. The impact of diet and lifestyle on gut microbiota and human health. Nutrients. 2014;7(1):17-44. Published 2014 Dec 24. doi:10.3390/nu7010017 (Section 3.2)