How human are you?

The human body is a complex organism which contains 21,000 genes.

But, inside all of us also reside 100 trillion bacteria, forming what is known as ‘The Microbiome’. Put together, the microbes within our microbiome will contain in the region of 4.4 million genes – meaning that the gene count of this ecosystem within us vastly outnumbers our own!

We are not unique in this either, microbes inhabit every animal body.


The idea of trillions of bacteria making themselves at home in the human body may make many people feel uncomfortable, but many of the microbes within the microbiome are not just beneficial to health – they are absolutely vital.

Bacteria get a lot of bad press, as we are encouraged to use anti-bacterial solutions and regard all bacteria as ‘germs’, and therefore the enemy. But, whilst there are bad guys out there, we now know beyond any doubt that there are also many different good guys. And we need them if we want to be healthy.


Up to 80% of the immune system in is the gut, (1) and research has shown us that gut flora plays a pivotal role in immune function. They are also important in the prevention of allergic reactions and inflammation.(2)

Looking after our good bacteria, then, is key to supporting healthy immune function.


Other research has indicated that taking antibiotics can cause such damage to our gut microbiome that, even one year after finishing a course of antibiotics, the gut flora will not fully recover. (3)

When we fit these two pieces of information together, it becomes easy to see how people can sometimes get stuck in a nasty cycle of almost constant infections. For this reason, many nutritionists will suggest that anyone who has used antibiotics in the previous 12 months should use a good, broad-spectrum, ‘probiotic’ supplement. This should provide at least 30 billion good bacteria per capsule.

We would also suggest that anyone taking antibiotics use a good, high strength good bacteria supplement alongside and for at least a month afterwards.


Every week we learn more about the different roles played by different bacteria.

If you are wanting to support your immunity and build up the number of good bacteria in your biome, look out for the following good guys:

  • Lactobacillus acidophilus – One of the primary functions of this bacteria is the production of lactic acid. (4) An increase of lactic acid within the gut will encourage the growth of other, beneficial bacteria. Lactobacillus acidophilus has also been shown to have a supportive action of the health of the immune response. (5)
  • Lactobacillus casei – Another bacteria which has been extensively studied for its immune boosting benefits, L. casei may also decrease inflammation. (6) It works well in combination with L. acidophilus, as it also works to increase lactic acid production within the gut.
  • Bifidobacteria lactis – B. lactis has been shown to work alongside L. acidophilus in supporting the immune system. (5) Some research has also indicated that this bacterium could reduce the damage done to the gut by conditions such as coeliac disease. (7)

Look out for next week’s blog, where I’ll be discussing how gut flora may impact our behaviour.

Written by Jenny Logan DNMed. (Jenny is a Nutritional Therapist who has worked with clients in health foods stores and private clinics for over 20 years)


(1) G Vighi et al; Allergy and the gastrointestinal system; Clin Exp Immunol. 2008 Sep; 153

(2) Purchiaroni F1 et al; The role of intestinal microbiota and the immune system; Eur Rev Med Pharmacol Sci. 2013 Feb;17(3)

(3) A. E. Perez-Cobas et al; Gut microbiota disturbance during antibiotic therapy: a multi-omic approach. Gut, 2012

(4) Gill HS et al; Enhancement of natural and acquired immunity; Br J Nutr. 2000 Feb

(5) W. Kneifel; Acidophilus Milk; Encyclopedia of Food Sciences and Nutrition (Second Edition); 2003

(6) Galdeano CM1; The probiotic bacterium Lactobacillus casei induces activation of the gut mucosal immune system through innate immunity; Clin Vaccine Immunol. 2006 Feb

(7) K Lindfors; Live probiotic Bifidobacterium lactis bacteria inhibit the toxic effects induced by wheat gliadin in epithelial cell culture; Clin Exp Immunol. 2008 Jun

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