Do you have the guts to be happy?

Some mood issues go beyond seasonal changes. There are many potential contributing factors, but one you may never have considered is the question of digestion. Could a damaged digestive system have an effect on your mood?

The answer is yes. Insights into the gut-brain connection have revealed a complex communication system that ensures the proper maintenance of gastrointestinal homeostasis and is also likely to have multiple effects on cognitive functions like mood. The complexity of these interactions is via the pathway of the “gut-brain axis” 1

The Digestive System – like a ‘second brain ’

Scientists have discovered that the digestive system acts like a ‘second brain’ producing neurotransmitters such as serotonin – a contributor to feelings of well-being and happiness. In fact, scientists estimate that 90% of serotonin is produced in the gut 2. If the gut is damaged in any way, this pathway will be disturbed.

How does gut damage happen?

If the gut has suffered a degree of damage – perhaps through the regular use of alcohol or painkillers, or through bloating, gut infection or antibiotics – you are more likely to react against the food you eat. The average person in Britain takes over 300 painkillers a year and the common ones, such as aspirin and ibuprofen, are the gut’s worst enemies, because they damage it, making you more prone to allergy.

Food allergies and intolerances have been proven to cause a diverse range of symptoms, including nervousness, anxiety and depression. Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders, having a prevalence of 12%-30% in the general population. Most patients with IBS attribute their symptoms to adverse food reactions. 3 Cytokines, activated by gut reactions, can make you feel depressed and have direct effects on the mood-boosting neurotransmitter serotonin.

Gut damage and ‘leaky gut’

A damaged gut can lead to intestinal permeability otherwise known as ‘Leaky gut’. There is evidence showing that intestinal mucosal dysfunction characterized by an increased translocation of gram-negative bacteria (leaky gut) plays a role in the inflammatory pathophysiology of depression 4. Allowing your gut time to recover is an important part of keeping it healthy and promoting good digestive and mental health.

How does glutamine fit in?

Where does glutamine fit into the equation? The simple amino acid glutamine, feeds the gut mucosa and helps to heal a damaged gut. Almost any food containing protein will contain some glutamine, but amounts vary. Animal foods are good sources due to their protein contents. Getting enough protein in your diet can ensure you are getting enough, but if your need is higher you may need to supplement. If the body’s need for glutamine is greater than its ability to produce it, your body may break down protein stores, such as muscle, to release more of this amino acid.

A randomised placebo-controlled trial carried out by Prof QI Qi Zhou and colleagues from Tulane University School of Medicine, concluded that the group that had been given 5g glutamine against the placebo group showed ‘intestinal hyperpermeability’ was normalised in the glutamine but not the control group 5.

How to improve gut integrity

So, if you think your gut is in need of repair, you will need to improve your gut integrity. The easiest and fastest way to do this is by taking two teaspoons of L-glutamine powder, one teaspoon at night, in water, just before you go to bed, and one teaspoon on rising, waiting an hour before you eat. Do this for one week.

You could also try a combination formula like my Digestpro, which provides probiotics both Lactobacillus acidophilus, bifidobacteria with glutamine and digestive enzymes for at least a month to give your digestive system a tune-up.

I’d also recommend identifying and eliminating any foods you may be intolerant to with York Test’s FoodScan home test.


1. Marilia Carabotti et al, The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems, Ann Gastroenterol. 2015 Apr-Jun; 28(2): 203–209

2. Catherine Paddock et al,  Gut microbes important for serotonin production

3.  Pasquale Mansuetto et al, Food allergy in irritable bowel syndrome: The case of non-celiac wheat sensitivity, World J Gastroenterol. 2015 Jun 21; 21(23): 7089–7109.

4. Maes M et al, The gut-brain barrier in major depression: intestinal mucosal dysfunction with an increased translocation of LPS from gram negative enterobacteria (leaky gut) plays a role in the inflammatory pathophysiology of depression, Neuro Endocrinol Lett. 2008 Feb;29(1):117-24.

5. Qui Qui Zhou et al, Randomised placebo-controlled trial of dietary glutamine supplements for postinfectious irritable bowel syndrome, Neurogastroenterology