In ‘Kimchi, Kombucha & Crushin’ – a Guide to Your Guts’ our resident nutritionist, Amanda Watts, delves into new research that explains the importance of the gut microbiome to our health and our ability to crush
Even if you have been dirt-bagging in the Grampians for the last year, it’s likely you’ve heard the phrase ‘gut microbiome’. Gut health–related messages are the latest health craze to hit the media, and for good reason. As gene sequencing has become less expensive and easier to access, our understanding of the gut microbiome has increased. It turns out our gut is a bit like a second brain. Research suggests that the massive colonies of microbes living in our gut may influence everything from our ability to climb hard, to obesity, disease and mental health. It is definitely worth trying to understand what our gut is all about and if we are able to alter it for the better.
Our gastrointestinal (GI tract) starts at our mouth, ends at the obvious exit point of our body and is as busy as an international airport. Trillions of microbiotas (an ecological community of microorganisms) live there and the genes inside all these cells are called the gut microbiome. In the average adult, this colony will weigh up to 2kg. Each person has a unique gut microbiome in the same way as they have unique fingerprints. Our gut bugs digest the food we eat (absorbing and synthesising nutrients), and are also involved in the function of our immune systems, metabolism and brain as well as influencing weight and mood.
There is some ground-breaking research being done, and from this we know that the gut microbiome changes throughout life. The first colony moves in just after we are born and for the first year it is very similar to our mum’s. Between the age of one and three, things like our diets and environment begin to influence how the colony grows and changes. From around the age of three years, our gut microbiome stays reasonably stable, though changes in our diets, injury, stress, fevers, illness and antibiotics are able to alter the blend of microbes in our gut colony.
Imagine if it were possible for your doctor to look at your gut microbiome, assess which microbes were missing, which ones shouldn’t be there and what numbers of each were better and then implant a gut-altering mix to change your weight or get rid of a disease. This is where the search for the magic bullet begins. At the Washington University School of Medicine researchers are looking for ways to treat malnutrition in children living in underdeveloped countries and obesity in the affluent world. They are doing this by transplanting gut microbial colonies (in the form of faecal pellets – yes, poo pills) from human donors into mice who are microbe free. The scientists then look at how these microbes influence the gut biome and body. They are also researching how different foods and diets can affect the gut colony.
Of course, the massive diet industry is desperately hoping the magic bullet will shoot out obesity – one weight-reducing pill of microbes to fix everything. So far what the research is revealing is that the microbes are significant but equally important is what we feed them. A rainforest is a good analogy to understand this concept. A rainforest can’t survive with just the animals and plants that live there. It needs the rain, sun and the nutrients in the soil to make it a thriving ecosystem. Our gut, it seems, works the same way. We need a very diverse colony of microbes plus a very diverse diet of good food to keep it healthy.
It is important to know that scientists are still a long way from understanding conclusively how different microbes influence our bodies and health, what the ‘ideal’ microbial colony is, the impact of implanting microbes into humans and the exact combinations of foods needed to support the ideal microbial colony. The goals are to work out which foods and probiotics (different strains of gut microbes) support and repair the gut microbe colony.
That said, there are some things that we can do right now to make our guts healthier.
- Avoid the things that cause dysbiosis. Dysbiosis is when the gut microbiome gets out of balance. Stress, too many antibiotics, illness, lack of activity, being overweight and eating a crappy diet can affect your gut. Diet is the easiest thing for us to change, which will in turn modify the microbial colony living in our gut. When we eat foods that are low in fibre, high in fat, very processed or if we eat too much meat, we are changing our gut bacteria for the worse, resulting in weakening of the intestinal wall, production of damaging gases and chemicals that we don’t want in our gut and essentially starving some of the good bacteria that we need for our health.
- Aim for 15g to 20g of resistant (RS) a day. It seems that 95% of our gut bacteria live in our large intestine (or large bowel). These bacteria like to feed on resistant starch. When they do this, the fibre is broken down into chemicals (bacterial fermentation), for example, short chain fatty acids, which do things like reduce inflammation and keep our intestinal wall healthy and leak free, help us absorb nutrients, inhibit growth of pathogenic bacteria and help stop us absorbing toxins and carcinogens. If we don’t eat enough resistant starch, we are essentially starving the gut bacteria and they can’t do their job properly. Research by the CSIRO tells us that this can cause the intestinal wall to become weak, potentially allowing undigested food, bacteria and toxins to leak into the bloodstream (which is not a good thing). If we don’t eat enough resistant starch the risk of colon cancer, Alzheimer’s disease, autism and irritable bowel syndrome increase. So where do we find resistant starch? We find it in starchy plant foods:
- beans and legumes (e.g. 2-3.5g RS/100g), whole and partially-milled grains seeds, corn;
- starchy fruits (such as bananas) and vegetables;
- and some types of cooked then cooled foods e.g. potatoes, rice (e.g. 1.2-1.7g RS/100g) and bread.
- Eat lots of fibre (prebiotics). Aim for a diet that is 80% plant based and 20% animal-based foods (except, of course, if you’re vegan). Fibre is all the bits of our plant-based food that get through the stomach and small intestine to the large intestine intact. These are mostly carbohydrates, and resistant starch is one example. By eating a diet high in fibre (lots of variety in fruit, vegetables, grains, pasta, rice, noodles, cereals etc.), we are increasing the diversity of our gut colony, slowing absorption of glucose and helping keep food moving in the direction it’s meant to.
- Eat fermented foods (probiotics). Foods that contain bacteria are called probiotics. Fermented foods like yoghurt, kimchi, sauerkraut and kombucha contain live microorganisms (e.g. yeast or bacteria) that are similar to the microorganisms living in our gut. It’s this bacteria, yeast or fungus that make the fermentation happen. Probiotics support our gut health in two ways: firstly, by helping break down the foods we eat and, secondly, by adding bacteria into our gut. The real thing is much better than taking supplements. When you take a supplement you are literally just adding that bacteria to your gut. If you put a probiotic supplement into an unhealthy gut they can’t survive – probiotic supplements are not a replacement for a healthy diet. When you eat pre- and probiotic foods you are helping keep the variety up in your gut colony, while you add good bacteria to your gut.
A healthy gut is necessary for a disease-free life and to keep us living and climbing the way we want to. Load your plate with lots of different vegetables (aim for >400g/day plus 100g tomato and leafy greens). Find ways to eat more lentils, chickpeas and beans, eat less red meat (aim for 150g max a week), eat some fermented food every day and don’t be scared of unrefined carbohydrates. Watch the gut microbiome space. It’s an awesome area of research into living a healthy life.
Sponsored by Evolv, Black Diamond and Beal, Amanda Watts is an Accredited Practicing Dietitian, Accredited Nutritionist and SDA Sports Dietitian at Thrive.