Bugs, or bacteria as the scientists like to call them, are making startling waves across the scientific literature. Most interestingly these waves are in the once place you are unlikely to think of – your colon.
Recent discoveries of bacteria living in the ‘deep and dark’ are starting to influence modern medical literature and the way doctors think about disease. Known as the gut microbiome there are trillions of bacteria found between your mouth and the other end. It is easy to think of the human body as an independent being but we are just starting to realise how much it actually relies on the complex ecosystem of many different microbes.
Research in this area has shown that the bacteria in our gut influence our metabolic function, regulate our immune system, and even play a role in brain development and behaviour. Current literature suggests that there are potential links between our gut bacteria and conditions such as diabetes, obesity anxiety, depression, and maybe even schizophrenia. The idea behind this is that the molecules and proteins secreted by the microbe colonies can interact with our nerves after perfusing into our brains.
Who would’ve thought that what goes on in our gut could influence how our brain works or even how well we can fight disease!
It has long been known that our microbiome can affect our absorption of nutrients but the recent discovery is that it also includes our metabolism – the way our body uses the energy that we absorb. Just browse the ‘fat mouse-thin mouse’ paper from the journal ‘Science’ – not actually called that but I think it is a better name. Transplanting the ‘obese microbe’ into the thin mouse made it fat – it had nothing to do with the caloric input. Now I don’t suggest you try fecal transplants at home, but it does raise important issues. Probably more concerning for humans is the role antibiotics potentially have in this complex interplay. Children who received more antibiotics before the age of 2 years were more likely to be obese than those that didn’t.
Are we killing off the good bacteria and allowing the microbiome to make us fat? And what else can we do to manipulate our microbiome? Here are 3 easy changes you can make to your diet to influence the metabolic and immunological activity of the gut.
THE 3 P'S - PREBIOTICS | PROBIOTICS | POLYPHENOLS
Probiotics are live micro-organisms, the most common are lactobacillus and bifidobacterium. Sources of these include yoghurt and other fermented products such as miso, kefir and sauerkraut. Whilst taking probiotics isn’t a magic bullet and the products you buy on the shelf at the supermarket aren’t standardized in any way – there are suggestions that certain combinations can help. Research has suggested that people who take a probiotic have lower stress levels and improved mood. It has also shown to have a positive effect on the immune system, with one study reporting fewer colds and gastrointestinal infections in the participants who took a probiotic compared to a placebo. Another study demonstrated that certain bacteria in probiotics could significantly lower total cholesterol as well the LDL cholesterol, known as “bad” cholesterol. They also suggested that it may have an underlying effect to reduce fat absorption from the gut. So in short, a daily dose of good bacteria can be linked to:
- Lower stress levels
- Improved mood
- Reduced number of colds
- Reduced number of gastro illnesses
- Reduced LDL cholesterol
- Reduced fat absorption from gut
If that’s not good enough reason to get into creating your own sauerkraut concoctions or kefir yoghurt at home, then I don’t know what will! If you need some ideas or have never heard of fermenting your own foods, The Nourished Kitchen has some great information and recipes to help get you started.
Prebiotics: These are food fibres that aren’t able to be digested by the gut cells and enable good bacteria to stick to the bowel wall helping to stimulate their growth. Prebiotics also discourage the growth of harmful bacteria. Imbalance of bacteria has been linked to inflammatory bowel disease, fatty liver, obesity, and even colon cancer. An easy way to increase your intake of prebiotics is to include more foods that are high in resistant starches and prebiotic compounds such as garlic, onions, asparagus, beetroot, green peas, lentils, beans, nectarines, rye bread, oats and cashews. Monash University has some great information and tips on how to follow a high-prebiotic diet.
Lastly there is Polyphenols. These are substances made by plants and are generally involved in the defense against ultraviolet radiation or disease-causing organisms. Whilst being new on the microbiome scene these compounds are known for their potential health benefits as an antioxidant to help combat cardiovascular disease and cancer. It seems that polyphenols act in a similar way as a prebiotic by increasing the amount of healthy bacteria in the gut. Even though there are many studies done on the range of health-promoting effects of polyphenols, their effect on the modulation of the gut ecology is only vaguely understood.
One link has been made with red wine. No doubt, we have all heard of its benefits, but a 2012 study published in the American Journal of Clinical Nutrition found when participants were given the red wine polyphenol over a 20-day period they had an increased number of beneficial gut bacteria when compared to placebo. Similarly, it lowered blood pressure and cholesterol. Some other sources of gut-loving polyphenols include berries, dark chocolate, and green tea. In fact the weight-lowering properties of these substances could be partly related to their polyphenol content and its direct link on the gut microbiota.
Pretty compelling evidence to show us the power of our gut! Just add the 3 P’s to your diet this year and see how your gut and your health will thank you for it.
 Mayer et al. (2014). Gut microbes and the brain: paradigm shift in neuroscience. The Journal of Neuroscience, 34(46):15490-6.
 Ridaura et al. (2013). Cultured gut microbiota from twins discordant for obesity modulate adiposity and metabolic phenotypes in mice. Science, 341 (6150).
 Baily et al. (2014). Association of antibiotics in infancy with early childhood obesity. The Journal of the American Medical Association Pediatrics, 168(11):1063-9. .
 Steenbergen et al. (2015). A randomized controlled trial to test the effect of multispecies probiotics on cognitive reactivity to sad mood. Brain Behaviour and Immunity, 48, 258–264.
 King et al. (2014). Effectiveness of probiotics on the duration of illness in healthy children and adults who develop common acute respiratory infectious conditions: a systematic review and meta-analysis. British Journal of Nutrition, 112(1): 41–54.
 Jones et al. (2012). Cholesterol lowering and inhibition of sterol absorption by Lactobacillus reuteri: a randomized controlled trial. European Journal of Clinical Nutrition, 66, 1234-1241.
 Carding et al. (2015). Dysbiosis of the gut microbiota in disease. Microbial Ecology in Health & Disease, 26:10.3402.
 Pandey & Rizvi (2009). Plant polyphenols as dietary antioxidants in human health and disease. Oxidative Medicine and Cellular Longevity, 2(5): 270–278.
 Queipo-Ortuno et al. (2012). Influence of red wine polyphenols and ethanol on the gut microbiota ecology and biochemical biomarkers. American Journal of Clinical Nutrition, 95(6), 1323-1334.
 Rastmanesh (2011). High polyphenol, low probiotic diet for weight loss because of intestinal microbiota interaction. Chemico-Biological Interactactions, 189(1– 2), 1–8.