The unseen role of microbiota for your gut health!

The human gastrointestinal tract is one of the largest surfaces in the human body, covering up to 400 m².¹ This is the equivalent to the size of two tennis courts! What’s more, covering this huge surface is the largest collection of microorganisms found anywhere in the human body!¹

This is approximately 10 times more microbial cells than human cells!¹

Bacteria make up the largest proportion of microorganisms (there are more than 1000 bacterial species found in the gut microbiota population, with ~60 predominant species)^2,3, however there are also viruses and fungi.⁴

This collection of microorganisms is called microbiota.²

 

A healthy gut is influenced by its microbiota

The microbiota live in a mutually beneficial relationship with the gut.¹ These helpful microbes can be found all along the gastrointestinal tract, but most are found within the large intestine.⁵ Very few are found within the stomach due to stomach acid, bile and secretions from the pancreas.⁵

This diverse collection of microorganisms helps with the normal functioning of the gut through various mechanisms, and there are different microorganisms that contribute to different health functions.¹

Gut microbiota functions

1. Contribute to energy and nutrient production including :
   • Fermentation of carbohydrates/sugars to produce substances that are used by the gut cells as an energy source⁶ ;
   • Digestion of proteins⁶ ;
   • Synthesis of vitamins such as Vitamin K and Vitamin B⁶ ;

Plus, there are even microbiota that ferment carbohydrates to provide an energy source for other beneficial microbiota in the gut!⁶

 

2. Influence gut cell growth and renewal⁷ ;
3. Help maintain a barrier which protects against pathogens⁷;
4. Stimulate the immune system.

Furthermore, the gut mucus layer provides a place for the microbiota to grow, and in turn, the microbiota provide a physical barrier to keep harmful microbes from accessing the gut cells.⁷

 

A relationship starting at birth that leads to a unique, personal collection of microorganisms, called microbiota

The microbiota are introduced to the gut at birth, from exposure to the mother’s microbiota.⁸ The microbiota composition of an infant is also influenced by factors including mode of birth (C-section vs. vaginal delivery), gestational age (whether they were born full-term), breast-fed vs. bottle-fed, illness and exposure to medications.⁸ The microbiota composition fluctuates during these early years but reaches stability around 3 years of age.⁸

In adults the gut microbiota composition is well-established and relatively stable.^1,9 In fact, each person’s microbiota is a very distinct and personal collection, and although it has been shown that there are predominant species common to all individuals, the composition and diversity can be influenced by a multitude of external factors throughout a person’s life.⁹

Diet is probably the biggest external factor that can influence microbiota composition.¹ For example it has been found that people who have plant-based diets have more microbes that are involved in the fermentation of plant fibres compared with people who eat meat (who have greater numbers of microbes that degrade proteins).¹⁰ Where a person lives can also determine the dominant species of a person’s microbiota.¹¹ This is because diets and lifestyles differ between cultures, which have a strong influence on the microbiota composition.¹¹

While the world around us can have a positive influence on our microbiota, it can also have a negative impact.⁴ For example poor diet, illness and exposure to medications such as antibiotics can skew the microbiota population^12,4. These drastic changes in microbiota can lead to reduced diversity and composition, which can have negative health consequences.¹³ This imbalance in diversity and composition is called intestinal dysbiosis.¹³  And for some factors such as antibiotics, the changes can persist for a long-time.¹³

Some probiotics has been demonstrated to restore balance to the microbiota when there is a disturbance.^5,14 Taking probiotics is recommended by many gastroenterology societies to help maintain gut health and microbiota balance.^5,15–18

 

Internal code : 20.40