It is surprising and staggering to learn that we are more bacteria than body. There are around 100 trillion microbes in our gut alone – way more than all the cells in our body – making our gut central to our health and happiness.
We picked up most of our microbes initially from our mother’s birth canal as we came into the world, or from the skin and the surrounding environment if we were born by caesarean. Once we are out in the open, multiple factors such as diet, antibiotics, genetics and stress all influence our microbiome, our own vital community of microbes that lives on and in us.
It turns out that the old wisdom, “follow your gut”, is upheld by recent studies and research. The full effects of those trillions of microbes living in our gut is beginning to be understood by science; in fact, the brain-gut connection seems to be a lot stronger than we thought. The gut microbiome has been linked to a range of behaviours such as, mood swings, stress, depression, anxiety and even neurodevelopment disorders, possibly including autism and hyperactivity. (see articles below)
We now know that the brain and gut are connected by the vagus nerve which links most of the organs within the body and plays an important role in activating the nervous system. Around 90% of the signals that pass along the vagus nerve come from the enteric nervous system, a huge complex of neurons which inhabits and controls the entire gut. Our enteric nervous system independently and automatically takes care of our nutrition and elimination, a huge job in anyone’s book. The brain then receives most of the information about the state of our body through the gut.
Stress and the gut
When we are stressed, our sympathetic nervous system is activated and the hormone ghrelin is released from our stomach. Ghrelin is also known as the hunger hormone because it stimulates appetite. This explains why some of us feel we need to eat when we are stressed. Ghrelin also leads to digestive issues and increased anxiety and depression over time. Increased anxiety then leads to more ghrelin production and this can start a damaging cycle.
IBS – Brain and gut disharmony
Stress leads to many medical problems, one of those being irritable bowel syndrome (IBS), a digestive disorder that affects 10-15% of the world’s population. IBS occurs when the gut, brain and microbiome aren’t working in conjunction with each other. This usually starts in childhood. As it matures, a child’s gut ideally develops a diverse culture of microbes that, in turn, creates a strong immune system. But many factors including diet, antibiotics, trauma and stress, damage the microbiome. And a damaged microbiome can lead to hyperactivity and medical problems such as food allergies. These symptoms often continue into adulthood where they are diagnosed as IBS.
Behavioural disorders and the gut
It appears that a disharmony within our physical microbiome can play a part in the development of neurological disorders like autism and ADHD. Factors such as antibiotics, environment and stress can fuel an already hyperactive system causing children (and adults!) to become impulsive and in a state of persistent hyper-arousal. If they also eat an unbalanced diet of processed foods and refined sugars this behaviour and symptoms will continue to get worse. A combination of unhealthy food choices and stress will create a flow of negative effects between the gut microbiome and the brain.
Rebalancing our gut microbiome and restoring harmony between our gut and our brain can be a key to overcoming many medical issues. To find out more, here is a list of articles about the gut-brain connection. Some outline steps you can take to correct your gut microbiome and have a positive effect on your overall health, short and long term.