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Health and the human microbiome: a quick introduction for beginners

Written by 
Dr Pablo Jeczmien
'Health and the human microbiome: a quick introduction for beginners' blog post.

The human microbiome is an incredibly complex and significant component of one’s health. Understanding its role in our health and contribution to overall wellbeing is integral to holistic approaches to treatment. Interest in this area has grown significantly in recent years, consequently changing the therapeutic landscape and the way in which practitioners address health concerns. Therefore, it seems fitting to delve into this topic to explain why indeed the human microbiome is positively sculpting the medical industry.

What does the term microbiome mean?

Bacteria, fungi, viruses and other microscopic living entities are commonly regarded as microorganisms, abbreviated to microbes. The human body hosts trillions of these microbes, although they are primarily abundant in the intestines and on skin. The majority of the microbes found in the intestines can be located in a ‘pocket’ of the large intestine known as the cecum and have been termed as the gut microbiome (GM). It is becoming largely accepted to regard the GM as its own organ which is crucial to one’s health; without which we would find it very difficult to live.

A brief explanation of the development of the gut microbiome

As you grow older your GM begins to diversify; a higher diversity is considered good for health. The most dramatic changes in its composition occur during infancy and childhood, factors which could affect this include:

  • Mode of delivery (natural or caesarean)
  • Gestational age (premature or full term)
  • Type of feed (breastmilk or bottle)
  • Use of antibiotics

These in addition to other factors are important to consider as they can impose developmental changes to the GM, which inextricably impacts health and key bodily functions later in life.

Why is it important?

There has been an exponential growth to the amount of research undertaken in relation to the microbiota of the human body in the last two decades; although it is fair to say that further research must certainly take place in order to fully comprehend the totality of the microbiome, its functions and effects on the different physical and physiological processes of the body. However, research to date has yielded promising indicators of health and disease when investigating this topic. More excitingly still, this research has started to permeate the boundary of the therapeutic landscape with suggestions that the gut microbiome plays an integral role not just in physical health and disease, but also mental health. Although, as aforementioned, further research is due in this field, some of the microbiome’s key roles have been well established to include:

  • Protection against pathogens
  • Synthesis of vitamins
  • Development of immune system
  • Promotion of fat storage
  • Modulation of the Central Nervous System (CNS)

What are the physical implications of the gut microbiome?

There are thousands of different types of bacteria located in the intestines, most of which are beneficial to our health. There are also different ways in which these bacteria and other entities composing the GM can affect key bodily functions and influence health. As an example, having too many unhealthy ones can increase the presentation of disease. An imbalance of microbes is sometimes known as gut dysbiosis. Ways in which our GM impact us can include:

  • Potential weight gain
  • Gut health and its associated functions
  • Heart health
  • Brain health: certain species can help to produce chemicals in the brain called neurotransmitters, for example serotonin, which is an antidepressant neurotransmitter primarily produced in the gut

It is also relevant to note that lower bacterial diversity has been repeatedly observed in individuals experiencing IBS, Psoriatic Arthritis, types 1 & 2 Diabetes, Atopic Eczema, Coeliac Disease, Obesity and Arterial Stiffness.

What are the physiological implications of the gut microbiome?

Having briefly explored the links between GM and a host’s homeostasis, it is important to subsequently explore its relation to physiological wellbeing. Significant progress has been achieved in the last decade to recognise the ways in which GM relates to brain function. Key findings indicate that stress influences the composition of the GM. Furthermore, a number of studies have shown that people with various psychological disorders have different species of bacteria in the gut compared to the general population.

Understanding the importance of gut health in relation to stress and other psychological issues has begun to instigate an evolution in the therapeutic landscape, particularly in developing the ways in which practitioners are able to treat individuals in a more integrative manner. It has been concluded that dietary and lifestyle choices affect the composition of the microbiome; when considering this, it is no surprise to see studies report that certain probiotics can improve symptoms of depression and other mental health conditions. In fact, a wealth of evidence now indicates that there are indissoluble links between metabolic and immune systems and the GM, which is being increasingly recognised as an important factor connecting genes, environment and immune system.

The microbiota-gut-brain (MGB) axis contains a pathway through which the specific microbiota influence cognition, mood and the CNS. As aforementioned, emerging research has placed the MGB at the epicentre of new approaches to mental health.

Studies have suggested that the GM can influence the precursor pool for serotonin, as well as playing an integral role in the programming of the hypothalamic-pituitary-adrenal (APA) axis in early life and according stress reactivity over the course of a life span. To further articulate this, studies have shown that dietary interventions can have the ability to alter intestinal microbiota which could promote beneficial amendments to cognitive ability.

What are the symptoms of an unbalanced GM?

There can be many symptoms of an unbalanced GM, sometimes it may be difficult to distinguish individual symptoms over a general feeling of ‘unwellness’ or imbalance. If chronic, this is certainly an issue that warrants further investigation with a doctor or specialist. Other distinguishable features can include:

  • Bad breath
  • Upset stomach
  • Nausea
  • Constipation
  • Diarrhoea
  • Difficulty urinating
  • Bloating
  • Chest pain
  • Rash or redness
  • Fatigue
  • Issues with executive functions
  • Difficulties with concentration
  • Anxiety
  • Depression
  • ADHD

How can I improve my gut microbiota?

There are various ways in which a GM can be positively manipulated, these might include:

  • Eating a diverse range of foods
  • Incorporating fermented foods into a balanced diet
  • Eating prebiotic foods
  • Limiting artificial sweeteners
  • Eating wholegrains
  • Consuming polyphenols as part of a balanced diet

Why is this relevant to mental health?

Although more thorough research is certainly due in this field of exploration, current results support the statement that the gut microbiome is integral to physical health, as well as an influence for mental health.

By taking a more integrative approach, one is able to ascertain the importance of addressing all aspects of physical and physiological health in order to achieve optimum wellbeing. The gut microbiome is a complex component to this approach which necessitates further investigation when considering a patients’ needs; a healthy microbiome will certainly contribute to the normal functioning of the body and thus its equilibrium, inclusive of producing some integral hormones and bodily responses which play key roles in the state of one’s mental health.

By working towards creating an inner sense of balance and wellness, the severity of symptoms from mental health conditions could indeed subside.

Final thoughts

This article has begun to outline the associations between GM, physical and mental states of health and balance. Furthermore, it illustrates the importance of maintaining a healthy GM for an optimum level of homeostasis. There are accessible ways in which an individual may be able to rebalance their GM, however if any of the topics raised within this article are relative to the reader, then the presiding advice would be to speak to a specialist in order to comprehensively investigate the issues at hand to regain balance and wellbeing.]

Please do not hesitate to contact me if you would like to seek further information or guidance on this topic, contact here

Further Reading