Your digestive system has many roles more than just processing your food, it is also responsible for your immune system and now researchers have discovered that it can also effect your mood.  

In a study they examined mice that lacked Gut bacteria in a maze that had a closed space and an open space, mice always avoid open spaces to prevent from being seen by predators.  Normal mice spent most time in the closed space but the mice that lacked Gut bacteria spent too much time in the open spaces.  This study then examined the animals brains and found that “these differences in behaviour were accompanied by alterations in the expression levels of several genes in the germ-free mice”, bacteria in the gut influence behaviour by inducing changes in the expression of certain genes”.

Your gut is literally your second brain that can influence your mind, behaviour and mood.  The researchers believe that your gut bacteria could play a role in the communication between your gut and your brain, and that gut bacteria is important immediately in the postnatal period because of the role in the development of the gastrointestinal, immune, neuroendocrine and metabolic systems. They say, “Gut microbiota regulates the set point for hypothalamic-pituitary-adrenal (HPA) axis activity”.  Serotonin is a neurotransmitter that activates this axis and has the greatest concentration in your gut.  Serotonin is involved in mood control, depression and aggression.

Therefore one of the most important things you can do is nourish your gut bacteria to help your psychological health and your mood; it can also influence the development of behaviour.

Another research says that gut bacteria may influence early brain development and behaviour and can permanently alter gene expression.  These bahavioural changes can be reversed as long as the bacteria colonized the gut before adulthood, once adulthood was reached without normal gut bacteria colonizing the gut did not effect their behaviour.  They state “there is a critical period early in life when gut microorganisms affect the brain and change the behaviour in later life”.

The nervous system and your gut are created out of the same type of tissue during fetal development, one into the central nervous system and the other into your enteric nervous system which are connected via the vagus nerve that runs from your brain stem (brain) to your abdomen which explains the saying “getting butterflies in your stomach” when you are nervous.  Therefore your diet is closely linked to your mental health, and good nutrition is important.

Have we also become to sanitized, with foods being processed and pasteurized, have we gone too far in killing all this bacteria and allowing yourself and children to have more natural food that has its own bacteria will actually strengthen up your immune system by helping the gut.

Antibiotics kill any of your good gut bacteria, the over use of antibiotics especially at a young age will in turn affect brain development and immune system. Antibiotics are also found in the water, and food sources such as non-organic meat.

Gut bacteria has approximately 85% ‘good’ and 15% ‘bad’ and helps with:

• Protection against growth of bad bacteria causing disease
• Digestion of food 
• Absorption of nutrients
• Producing vitamins and eliminating toxins
• Preventing allergies

Having excessive unhealthy bacteria is termed Candida and can have the following symptoms:

• Gas and bloating
• Fatigue
• Constipation or diarrhea
• Nausea
• Headaches
• Sugar cravings

What effects healthy gut bacteria?

• Antibiotics
• Chlorinated water
• Processed foods
• Pollution
• Stress

80% of your immune system is located in your gut so it’s important to maintain a healthy gut, you can do this by:

• Fermented foods such as lassi (yoghurt drink), kefir (fermented milk), pickled fermentations of cabbage, turnips, eggplant, cucumbers, onions, squash and carrots and natto (fermented soy), make sure these haven’t been pasteurized as it kills natural probiotics.
• Supplement with a good probiotic.

References: 

1. Neufeld et al, 2011. Reduced anxiety-like behavior and central neurochemical change in germ-free mice. Neurogastroenterology & Motility. Volume 23, Issue 3, pages 255-e119, March 2011.
2. Heijtza et al, 2011. Normal gut microbiota modulates brain development and behavior. PNAS, February 15, 2011, vol. 108, no. 7, 3047–3052.