Updated 24 April 2018

How do probiotics benefit us?

We take a look at how these microorganisms can boost your health.


Probiotics affect the digestive-tract ecosystem in three ways:

1. Probiotics change the way in which the gut lining reacts to inflammation 

Probiotics help to activate white blood cells called macrophages, which use the process of phagocytosis to engulf foreign particles and digest them. 

Once these particles have been digested, our B cells (another type of white blood cell) produce antibodies against the foreign body, while immunoglobulin A (IgA – a type of antibody) is released into the digestive tract.

IgA is the first line of defence against ingested pathogens. 
The above mechanisms all help to prevent infection of the gut lining.

2. Probiotics interact with other species of bacteria that inhabit the gut 

These species include pathogenic substances and/or harmful bacteria.

Probiotics are able to: 

  • Digest food and compete for nutrients with pathogens. If healthy bacteria predominate in the gut, the pathogens will be left without “fuel” and will be more likely to die. To put it differently, the probiotics create a competitive environment in which the harmful bacteria struggle to survive.
  • Change the pH in the gut to a less favourable pH for pathogens – again making it harder for the harmful bacteria to survive. 
  • Produce a substance called bacteriocin, which stops the growth of similar or closely related bacterial strain(s). In this way, probiotics also inhibit the growth of pathogens. 
  • Change the way in which pathogens produce toxins.
    These benefits all enhance your digestive tract’s ability to fight pathogens and infection of the gut lining.  

3. Probiotics generate short-chain fatty acids (SCFAs)

SCFAs are receiving a lot of attention in gut-related research, as they’ve been shown to exert multiple beneficial effects.

Research shows that they:

  • Are a key energy source for the cells lining your colon. In this way, they keep the colon in good working condition.
  • Have been linked to the prevention of colon cancer.

Reviewed by Kim Hofmann, registered dietitian, BSc Medical (Honours) Nutrition and Dietetics, BSc (Honours) Psychology. April 2018.


Read Health24’s Comments Policy

Comment on this story
1 comment
Comments have been closed for this article.

Live healthier

Mental health & your work »

How open are you about mental illness in the workplace?

Mental health in the workplace – what you can do to help

If you know that one of your colleagues suffers from a mental illness, would you be able to help them at work? Maligay Govender offers some helpful mental health "first aid" tips.

Sleep & You »

Sleep vs. no sleep Diagnosis of insomnia

6 things that are sabotaging your sleep

Kick these shut-eye killers to the kerb and make your whole life better – overnight.