The surge in research about our gut bacteria has hit the roof, so to speak, recently. There is more and more evidence arising about how our gut bacteria not only is hugely influenced by what we eat, but more importantly - that our gut bacteria may be having huge influences on how we feel. Yes, that's right, whether we are happy, sad, anxious, depressed or otherwise 'not quite right'.
"Micro-organisms in our gut secrete a profound number of chemicals, and researchers... have found that among those chemicals are the same substances used by our neurons to communicate and regulate mood, like dopamine, serotonin and gamma-aminobutyric acid (GABA)." (Link)
There is also now a suggestion that the type of bacteria in our gut - can impact our weight - that different bacterias will help process food in different ways affecting the calorie component we eventually receive.
New evidence indicates that gut bacteria alter the way we store fat, how we balance levels of glucose in the blood, and how we respond to hormones that make us feel hungry or full. The wrong mix of microbes, it seems, can help set the stage for obesity and diabetes from the moment of birth. (How Gut Bacteria Help Make Us Fat and Thin)
Our gut (stomach, bowels, intestines) are full of micro-bateria. In fact it is suggested we can hold up to 2kg worth of gut bacteria. It lives in a fine balance of appropriate levels of so called 'good' and 'bad' bacteria. It serves an amazing range of functions: from helping to synthesise and produce some vitamins, helps to digest certain foods and most importantly it helps to support our immune function. Although we are born 'sterile' - we begin accumulating micro-bateria the moment we are born - and if we are lucky - and born vaginally - this initial coating of vaginal micro-biota can impact our health for many years to come.
I personally think the impact of our gut bacteria is best explained in the video by Scrubs - "Everything comes down to poo...." (Go and take a look now - it's worth a watch). And it seems that science is backing this little ditty up more and more.
The weirdest thing that has evolved from the discovery of the importance of the our microbiome is faecal implants (yep, you guessed correctly - transferring poop from one being to another). It not only helps treat all sorts of gut complaints, in animal studies, it also can change the behaviour in mice or monkeys. Ie the formally anxious mouse, becomes less anxious when implanted with a chilled out mouses gut bacteria (from it's poop). Faecal transplants have been used in humans also - mostly to treat symptoms of chronic diarrhoea (such as the bacteria clostridium diff.) and other bowel disorders (such as irritable bowel syndrome and colitis) but some transplants have been shown to improve the behaviour of autistic children with good results. (An example of that here.) There are more studies needed on autism as the results are mixed, but some research suggests autism may be related to disordered gut bacteria.
Antibiotics are one of the most damaging things to both the 'good' as well as the 'bad' bacteria in the gut and should be avoided unless absolutely necessary. In some individuals it can take up to one year for the gut bacteria to return to its normal state.
Unfortunately we are not yet up to the point of being able to 'prescribe' a certain type of bacteria for treating mood symptoms, but there have been some promising studies (once again - mostly on animals) in treating some behaviours (such as anxiety) with specific microbacteria.
There is something we can do to ensure that our gut bacteria is up to scratch so to speak... and that has to do with what we eat.
Firstly: To improve our gut bacteria - we need to consume 'pre-biotic' foods. These are the food that probiotics love to feed on. This includes high fibre fruits and vegetables, such an onions, leeks, kale, celery, artichoke, aparagus, broccoli (often the more fiberous the better eg the salks of the broccoli), and other foods such as garlic, oats and bananas (which contain some anti-inflammatory properties) and blueberries (seem to do wonders for our gut and out immune system).
Secondly: Add in the probiotic containing foods. This includes yoghurt, naturally fermented vegetables such as the Korean kimchi, sauerkraut, and picked vegetables.
Food advice: Get back to the basics. The tried and true advice which we all know but sometimes choose to ignore: Avoid processed foods and simple carbohydrates. Eat mainly fruits and vegetables, not too over-cooked, some raw and eat all the colours of the rainbow.
Other advice? Get a pet - they carry a range of bacteria which increase our own (the more we have - the better). Get rid of the hand sanitiser (in fact all anti-bacterial soaps and sprays - they kill all bacteria - good and bad). Play in the dirt - soil is full of bacteria shown to have positive effects on our health. The more diverse your gut bacteria - the better for your health.
It only takes a few days of a change in diet to change the micro-bacteria in our gut - a few days for example of high sugar, low fibre eating can produce major changes in our gut microbes (for the worse).
Go well. Go feed your gut! Your brain and body will love you for it :-)
(For some fascinating research on this topic, check out the Human Food Project. The lengths people go to!)
Gut Check: Exploring Your Microbiome (Coursera MOOC)