The human microbiome; your gut has never been sexier, and here’s why.
Gut health is so hot right now. Are you into it? You should be.
The gut is our second brain. There are millions of nerves and chemicals constantly communicating between the gut and brain. This might explain why some of us are always thinking about our next meal.
You know how when you’re about to give an important presentation at work, or go on a tinder date, you get ‘butterflies’ or feel nauseous? That's your brain talking to your gut through your enteric nervous system.
Similarly, your gut can communicate with your brain. When you’ve been eating poorly, your gut will send a message to your brain, causing to you to feeling anxious or unhappy.
Improving your gut health has the potential to improve your mental health, keep you at a healthy weight and prevent nearly every disease you can think of. Unfortunately, everybody wants to say their bit on this topic and there’s some questionable advice floating around.
Let’s start with the basics. A microbiome is basically a teeny tiny world of microbes; mainly bacteria but also viruses and fungi. Are you picturing a city of microbes with their miniature sky scrapers, electric powered cars and squeaky voices? Perfect, this is exactly what it looks like.
Most of us know about the existence of our gut bacteria. But do you know that we also have separate microbiomes on our skin, and inside our mouths, lungs and genitals? Each of these worlds look completely different but are equally important for our health. The ‘good bacteria’ in each of these worlds thrive under very particular conditions.
Keep in mind, excess alcohol, stress, harsh skin products and genital washes can disrupt the pH in these worlds. This can cause the nasty microbes to thrive, leading to infections and disease. Ain’t nobody got time for that.
Side note: I’ve noticed that a few skin care brands have started including gut probiotics in their skin products. The primary strains of bacteria in the gut are completely different to the skin, so these products would be completely ineffective. I’m sure this will be an exciting area once we know more about the skin microbiome, it’s just not worth wasting your money on these products just yet.
When did you develop your microbiome?
Sorry to bring up this graphic image, but when you passed through your mother’s vaginal canal (I’m sure you remember it vividly), this was your first introduction to some friendly microbes. Did you know that babies born by caesarean section are more likely to develop allergies, asthma and diabetes? This is because they didn’t have this initial opportunity to establish their microbiome.
From this point on, your microbiome continued to flourish through interaction with your environment. Breastfeeding was extremely important to establish a diverse range of gut microbes.
Congratulations, you’re now an adult with an established microbiome. To be a responsible host, here are five facts you should know about your gut:
1. The more, the merrier.
Having a diverse range of gut bacteria is a good thing. As different bacteria thrive from different nutrients, eating a diverse range of foods will help to encourage this.
2. Gut microbes aren’t fond of antibiotics.
Studies have found that while most individuals’ microbiomes were restored approximately one week following antibiotic completion, some did not fully recover for four years and permanently lost certain types of bacteria.
3. You have the power.
Stress, weight gain and poor diet can influence our gut bacteria profile but these negative changes can begin to be reversed very quickly after adjusting our lifestyle.
4. Your gut is unique and special, just like you.
Certain bacteria in your gut can digest different foods for you. Your personal bacteria profile will influence how well you tolerate certain foods and how well you digest them. This is one of the reasons why I don’t believe that there is one perfect diet that works for everyone.
5. Playing with poo has interesting outcomes.
When a fecal transplant of the gut microbes from obese mice were put into the gut of sterile mice, the sterile mice were found to harvest more energy from the food and gain weight – even though consuming exactly the same food as the control mice. In other studies, the transplant has resulted in increased hunger levels.
How do I improve my gut health?
The good news is that we can change our microbiome within just one week of making improvements to our diet. But how do we do this?
As the gut is so complicated, there have been a number of conflicting studies published in this area.
One theory is that eating a fibre-rich diet increases the Bacteroidetes and reduces the Firmicutes. That’s all well and good, but what the hell are Bacteroidetes and Firmicutes? To keep things simple, think of these as categories of bacteria.
More Firmicutes and fewer Bacteroidetes have been associated with a low fibre, typical ‘western diet’, containing plenty of refined sugar, high fat animal products, alcohol and processed foods.
If you have too much of the bad bacteria (Firmicutes), this may result in you getting more calories from your food and being hungrier. This may lead to weight gain and stress, which will promote the bad bacteria even further, in an unhealthy cycle.
The bottom line is: eat lots of fruit, vegetables and wholegrains and avoid processed ‘junk’ food, excess alcohol and too much red meat. This will have positive effects not only on your gut but many aspects of your wellbeing.
What about probiotics and fermented food?
Probiotic supplements have shown to be beneficial for individuals with Irritable Bowel Syndrome (IBS) and for people receiving antibiotic treatment. There has not been any compelling evidence to suggest that taking probiotics can benefit already healthy individuals.
Also, probiotics are obscenely expensive. Save your money and spend it on delicious high fibre foods that will benefit your gut.
Fermented foods such as sauerkraut, kimchi, kombucha, kefir and yoghurt contain a more diverse range of bacteria than probiotic supplements, along with other beneficial nutrients, so I would recommend eating fermented foods over taking probiotics.
You would be surprised, given how obsessed everyone is with sauerkraut and kombucha, how little evidence there really is to suggest that fermented foods have any benefit at all in humans.
However, only a small handful of studies have looked at the effect of fermented foods on human health. So, it’s entirely possible that the science is yet to catch up on this health trend.
Personally, I’m addicted to kombucha. I won’t judge you if you don’t judge me.
Pay attention to your body and mind, and do what feels good for you when it comes to your gut health.
Castaner, O., Goday, A., Park, Y. M., Lee, S. H., Magkos, F., Shiow, S. A. T. E., & Schröder, H. (2018). The Gut Microbiome Profile in Obesity: A Systematic Review. International journal of endocrinology, 2018.
de Moraes, A. C., Fernandes, G. R., da Silva, I. T., Almeida-Pititto, B., Gomes, E. P., Pereira, A. D. C., & Ferreira, S. R. (2017). Enterotype may drive the dietary-associated cardiometabolic risk factors. Frontiers in cellular and infection microbiology, 7, 47.
Hehemann, J. H., Correc, G., Barbeyron, T., Helbert, W., Czjzek, M., & Michel, G. (2010). Transfer of carbohydrate-active enzymes from marine bacteria to Japanese gut microbiota. Nature, 464(7290), 908-912. doi:10.1038/nature08937
Ursell, L. K., Metcalf, J. L., Parfrey, L. W., & Knight, R. (2012). Defining the human microbiome. Nutrition reviews, 70 Suppl 1(Suppl 1), S38-44.