Eating for trillions: How feeding our microbiome is a deliberate act of self-care

Author: Ellen Twomey, PhD Student, APC Microbiome Ireland, University College Cork
Self-care is key to capturing happiness. How do you undertake selfcare? Exercising, drinking water, or taking a rest day maybe? When defining “self”, I am curious if you include the trillions of microorganisms that call us home? Despite their overwhelming presence, they are easily forgotten. Your microbiome is an extension of yourself, a clandestine organ invisible to the naked eye that needs to be cared for just like the more substantial elements of our bodies. These bacteria directly affect our physical wellbeing as well as our mental health. There is a stack of evidence demonstrating that if we mind our microbes, they will mind us in return, and it turns out one of the easiest ways to pamper them is by choosing what we put on our plates.

The Impact of Diet on Our Microbiome: A Closer Look

It is widely understood that our diets and lifestyles impact our health. But are you aware that they can also radically shape our internal bacterial landscape? After a weekend fuelled by takeaways high in sugar, salt and low in fibre, you can feel bloated and sluggish. Deeply interconnected with our own cells, the bacteria composing our microbiome would be suffering a similar fate. Over time, deprived of their preferred nutrients, many species die out and are permanently eradicated from their respective niches. While a bit dramatic, declining microbial diversity is a widely reported phenomenon and is predominantly observed in cultures subsisting on a Western diet i.e. high in processed foods. Research comparing the bacteria isolated from the faeces of those living off a typical industrialised diet vs those from individuals consuming minimally processed, fresh ingredients, has shown that our poor dietary choices are driving bacteria out of our bodies.
The significance of this loss in diversity is not always apparent at first, but gradually grows to reveal the true extent of the issue. The bacteria within us are not idle bystanders as we carry them through life. Our microbiome is actively contributing to the upkeep and maintenance of its home: aiding digestion, providing micronutrients, and suppressing inflammation. Of particular interest to my line of work is how these organisms act as an additional component of our immune system and work to fight off colonisation and infections caused by invading bacteria. You don’t need to look far to find examples of the protective role of our microbiome in everyday life. Following a course of antibiotics, it is not uncommon for patients to develop a secondary infection. This is due to good bacteria getting caught in the crossfire and accidentally getting killed off alongside the offending pathogen. You may have a heard of “C. diff” (short for Clostridium difficile), a nasty gastrointestinal dwelling organism that rears its head whenever the healthy flora is disrupted. To reduce the likelihood of suffering the effects of a C. diff infection, probiotic foods are sometimes recommended as they can help build up the healthy gut flora affected by antibiotic consumption.
In some cases, however, the bacterial composition of the gut can become so dysregulated that C. diff infections are abnormally recurrent despite antibiotic intervention requiring a more drastic measure to be taken. Faecal transplantation is a technique stranger than science fiction, involving samples of poo from a person with a healthy, balanced microbiome being placed into the gut of the individual requiring treatment. Admittedly a pretty gross affair, faecal transplants quickly and effectively restore crucial missing microbes to the intestinal ecosystem and prevent repeat infections better than other treatment routes. It is clear evidence on our reliance on the protection provided by our microflora and spells out the consequences of their absence.

Nourishing Your Microbiome: A Vital Task

Taking the time to cultivate and support your microbiome is as important as brushing your teeth. We can use food as a tool to build ourselves up at a microscopic level. From day one, our bodies are prepared to facilitate colonisation by the good bacteria that will (hopefully!) accompany and support us through the rest of our lives. Breast milk feeds both the growing newborn and the bacteria spreading in its gut. However, dinner time gets more complicated when we eventually need to make dietary choices for ourselves, as it can be a struggle to not get lost in a sea of calorie dense, nutrient deficient convenience foods.
Amidst the chaos of twenty-first-century food shopping are many wonderful microbiome supporting options if you know where to look. Fermented products such as kimchi, sauerkraut, and kombucha have been studied for decades due to their connection with gut health. They are naturally a rich source of probiotic bacteria hard at work increasing the bioavailability of vitamins and producing substances which exhibit antioxidant, anti-inflammatory effects, and anti-diabetic properties. These by-products support our cells and can nourish our microflora at the same time. Sauerkraut and kombucha may not be to everyone’s taste but consider eating live culture yogurt and other probiotic dairy products for a similar effect. Lactic Acid Bacteria (LAB) are the microbes responsible for these dietary perks. They can be found all throughout our bodies – from the oral cavity to the end of the GI tract. When consumed, LAB can survive passage through the acidic environment of the stomach and settle in our gut where they can continue providing us with their benefits long after the meal is done. Women in particular benefit as LAB play an enormous role in vaginal health, preventing bacterial vaginosis which can have serious implications on fertility and has been tied to premature birth.
But food can also provide our microbiome with the building blocks required for important nutrients that we are unable to produce ourselves. Fibre is an indigestible carbohydrate present in cereals, fruits and vegetables. Upon reaching the gut, fibre rich foods are greedily broken down by our trillions of tiny companions and converted to Short Chain Fatty Acids (SCFAs). SCFAs are an important energy source to the intestinal epithelial cells and have been found to improve the gut barrier function. An important mediator in the gut – brain axis, SCFAs also tie in with brain health. There is new data suggesting SCFAs protect the blood-brain-barrier which may impact the development of neurovegetative disorders like Alzheimer’s disease, though this is still a developing area of research. Despite the fact serotonin is active within the brain, it has been found that the over 90% is produced in the gut. Fibre feeds these serotonin-producers, positively impacting mental wellbeing. If enough good things haven’t been stated already, diets rich in fibre and the presence of healthy bacteria in the gut are linked to a reduced likelihood of colon cancer. So maybe an extra helping of veg isn’t such a bad thing?

Food: A Deliberate Act of Self-Care for Our Microbiome

Food is used as a means of socialising, celebrating different cultures, and it can even be an expression of love. As time goes on, we are learning more and more on how food can be used as a tool to manipulate our microbiomes and draw out the potential of the bacteria within us. For the low price of providing dinner and a place to stay, we receive a wealth of health benefits that can help us live happier, healthier, more microbially diverse lives. Feeding our bacteria is an easy task but it must be conscious one, a deliberate act of self-love. Fermented foods, probiotic dairy products and fibre are easily identifiable targets when it comes to supporting our microflora and this can be built upon over time. Drinking more water, reducing salt intake, and exchanging convenience foods for fresher ingredients – these little changes can yield huge returns. Even though they are small, and sometimes a bit smelly, a full and robust microbiome is something we can’t take for granted, it is a symbiotic relationship after all – a bit of give and take is required. Maybe the next time you decide to treat yourself, think of treating your whole self, and all the little passengers being carried along with it!