One on the newest areas of research is the way the food we eat, and the lives we lead effect the bacteria that sits in out gut. The connection between the gut and the brain is significant with many scientists suggesting it to be the "second brain". No one can disagree that a food intolerance (e.g. lactose or gluten) can cause physical symptoms as well as physiological ones such as feeling generally lethargic and under the weather. There is now evidence to suggest that the enzymes and bacteria in your gut has significant effects on everyone (in-tolerances or not) with some links to conditions such as depression.
The digestive system is home to trillions of micro-organisms that colonise the gut, this is called the gut flora. A healthy adult has about 2 kg of this bacteria in the gut and the beneficial bacteria is considered to be the housekeepers of the gut. They take part in our digestion and the absorption of our food, producing a number of enzymes that break down proteins, carbohydrates, fibre and fats. They produce various substances that transport the vitamins, minerals and other nutrients received from food. So this bacteria is not only essential but is in itself its own ecosystem. Like any ecosystem any change can cause an imbalance and this imbalance between good and bad bacteria is why our gut can influence our health so much.
The gut flora has many functions:
Protects from pathogens - By taking up all the space, making use of all available nutrients, and by secreting compounds that kill or inhibit unwelcome organisms that would compete for nutrients with it. Always worth paying special attention to your gut before heading off on a tropical adventure, could save you the pesky travel tummy.
Development of the immune system - A large proportion of our immune tissue sits in the gut, this is called gut-associated lymphoid tissue (GALT). During our first few years of life, the microbiome of our guts actually trains the human immune system how to perform its job. Disease fighting microbes (the good guys) directly attack the disease-causing microbes (the bad guys), thereby signaling to the human immune system when to launch an attack against the threat. Problems with this training can be linked to auto-immune diseases (immune cells attacking itself), allergies (over active immune response) and immune deficiency.
Metabolism - The human body cannot digested all carbohydrates it consumes, some types of gut bacteria have enzymes that human cells lack allowing these to be broken down. These broken down carbohydrates provide a major source of useful energy and nutrients.
Links between the gut and the central nervous system - Microbes in our gut may influence our mood in ways that scientists are just now beginning to understand. Scientists have proven the brain uses signaling molecules to influence gut bacteria, but there is now evidence that such communication is two-way. Your gut can also direct your brain to tell you what to consume. There is evidence bacteria can synthesize chemical signals to control your behavior, and even manipulate feelings by producing compounds that turn into the neurotransmitters dopamine and serotonin, linking them to depression.
Its important for your gut to be healthy and in balance, however it is considered that 80% of people do not have the optimal balance of bacteria. One problem that is quite common is having too much yeast in the gut, its normal to have a small amount but at times you can have too much. This can be caused by having too much refined carbohydrates, sugars, alcohol as well as high stress levels or a course of antibiotics that have killed off too many friendly bacteria. Signs can be feeling tired and worn down, getting bloated, gaining weight, being irritable and having strong sugar cravings. This may be why we get caught up in a cycle of eating poorly and feeling low.
As you can see gut bacteria is actually quite important, with links being made between bacteria and weight management, depression, food cravings and immune disorders. Luckily there are things we can do to ensure our gut bacteria is in check, the next post can tell you how.