Microbiota and depression: the relationship between your diet and your mood

Microbiota and depression: the relationship between your diet and your mood

Humans are complex beings and there are many factors that can affect our state of health. One of them is the “intestinal microbiota” popularly known as ” flora “. In this article I will explain to you what is the relationship between the microbiota and depression . 1

Functions of the microbiota or “flora”

The gut microbiota or “flora” is defined as the microbial ecosystem that colonizes the gastrointestinal tract. It is so important that it is even beginning to be considered as just another organ. The set of these microorganisms that live inside our body supposes up to 2kg of our body mass, a quite remarkable weight for how tiny these beings are, don’t you think?

And of course, being so many, it is logical that they can exert some effects on our health:

  • Synthesis of compounds such as vitamins (Vitamin K, Vitamins of group B).
  • Facilitates the absorption of certain minerals (calcium, iron).
  • Protects from the implantation of external pathogenic bacteria avoiding infections.
  • Strengthens the immune system against different types of infections.

But what if in addition to all this I tell you that it is capable of communicating with your brain affecting your mood , do you believe me? Not? Now you will!


Can the microbiota affect our mood?

The answer is YES, but for this we must first understand how it is possible to communicate with such a physically distant organ.

The microbiota is capable of communicating with the brain through various mechanisms such as: 2

  • Stimulate the immune system.
  • Through the vagus nerve (a nerve that connects the stomach and part of the intestines with the brain).
  • By hormonal responses.
  • Even by certain molecules that certain bacteria produce.


Major depression and its relationship with the bacteria of our microbiota

Now I want us to focus on major depression , what is it exactly?

The Major depression is an emotional disorder that causes a feeling of constant sadness and loss of interest in different activities. It affects 300 million people, causes functional disability and is even associated with approximately 800,000 suicides per year. The depressive disorder greater the psychological disorder more modulated by these little friends.

In a recent review, it was observed that patients with depression had a higher amount of bacteria from the Bacteroidetes, Proteobacteia and Actinobacteria families , while they had lower levels of Firmicutes . While there are patients with greater protection against the disorder who have a greater amount of Lactobacillus and Bifidobacterium . This makes it clear to us that these types of patients already have a different type of inhabitants compared to people without the disorder. 3

Regarding molecular mechanisms, I am not going to delve into more detail, but I leave you two articles on the two most important routes that the microbiota can modulate in case it is of interest:

  • That of Serotonin (the hormone of happiness): O’Mahony, S. (2015) 4 .
  • That of GABA (gamma-amino butyric acid): Mazzioli, R. (2016) 5 .

With these data we can already imagine that it is a very serious thing, and to reassure you, we are going to talk about how what we eat can help us keep our microbiota happy and send beautiful messages to our brain. 6

flora or microbiota

Now, how can nutrition help with the microbiota and depression?

It is logical to think that the microbes that live in our intestines take advantage of the food that passes through there to nourish themselves, now, what are the nutrients or foods that would help (or not) to prevent or treat that depression?

  • Mediterranean Diet: A systematic review (higher scientific quality) that collected data from a total of 1,959,217 people (WOW!) Determined that people who adhered to a high-quality diet (specifying the Mediterranean) had greater protection against depressive symptoms together with a lower inflammatory index attributed to the higher specific consumption of fish and vegetables. 7
  • Ultra-processed foods: A cohort study that evaluated 14,907 Spanish people (it is not so good scientific quality, but it has a significant number of participants) free of any type of depression, determined that the chronic consumption of this type of food is capable of increase the cases of depression, diagnosing 774 cases in the time that the study lasted. 8
  • Omega-3 fatty acids: A randomized and controlled study carried out in 4 European countries showed that the supplementation of> 1g / day of EPA and DHA (omega-3 fatty acids) in patients with the disorder already present, obtained an improvement in the depressive symptoms presented by patients under treatment with antidepressants. 9

On the other hand, there are treatments that are being evaluated to be used in the future such as the use of psychobiotics (supplements with healthy intestinal microbiota for your brain) and fecal transplants (it sounds as bad as it is).


What do I recommend as a Dietitian-Nutritionist?

  1. Take a eating pattern as Mediterranean as possible.
  1. Increase the consumption of seasonal vegetables and fish (and if possible from proximity).
  1. Avoid ultra-processed food as much as possible as it has been shown not to be beneficial for depression or health .
  1. In case you suffer from this state and are under treatment with antidepressants , talk to your doctor and assess the supplementation of> 1g / day of omega-3.
  1. Exercising moderately improves depressive symptoms and should be considered in patients with the disorder. 10

I hope you found the topic that I selected today interesting and that it may be of help to more than one person.


Leave a Reply

Your email address will not be published. Required fields are marked *