Diet & Gut microbiota

The influence of diet on gut microbiota

The food we eat plays an essential role in maintaining the diversity and proper functioning of our gut microbiota.
When talking about gut microbiota, it could be said that “we are what we eat", as what we consume also feeds off the hundreds of trillions of bacteria living in our digestive system. For this reason, a varied and balanced diet is essential.

The food we eat plays an essential role in maintaining the diversity and proper functioning of our gut microbiota.

Prebiotics and probiotics are two of the most widely studied elements in the field of gut microbiota. Both have effects that are considered beneficial for the gut microbiota which impacts various functions of the body such as the digestive condition, for this reason, specialists highlight the importance of including both of them in our diet, in order to promote a healthy microbiota.

Prebiotics

The concept of the prebiotics, sometimes called fermentable fibre, was initially introduced in 1995 by Gibson and Roberfroid. It is defined as the indigestible ingredients in food that selectively promote the growth and activity of a limited number of autochthonous bacterial species, and thus conferring a benefit for the host1. Prebiotics can be found naturally in food or added to them (functional products).

Prebiotics are naturally present in vegetables and fruit such as garlic, onions, leeks, asparagus, artichokes, tomatoes, bananas, plums and apples; in grains and cereals like bran, and in nuts like almonds. For this reason, vegetables, fruits and cereals should be part of a balanced and healthy diet.

As in many other fields, balance and variety are essential when eating prebiotic foods. Although a fibre-rich diet benefits gut bacteria, excess fibre may lead to discomfort or abdominal bloating in some people.

For further information on prebiotics, why not check out this information sheet from the International Scientific Association for Probiotics and Prebiotics – ISAPP.

Probiotics

The World Health Organization defines2 probiotics as live microorganisms which, when administered in adequate amounts, confer a health benefit on the host.

These microorganisms partially resist to the digestion process, alongside to the progression in the digestive system3. They provide a range of benefits for the body, including the maintenance of digestive comfort and the regulation of the immune system . Probiotics can also help balance the gut microbiota when it has been affected by poor diet, infections, some antibiotics treatments or other external factors such as stress4.
Many probiotics come from bacteria traditionally used for fermenting food. At the present time, a large number of relevant (well-designed) clinical trials with probiotics have been performed and the most common probiotics studied belong to two genera, Lactobacillus and Bifidobacterium, but other microorganisms including Enterococcus and Streptococcus, among others, have been also studied.

Studies have shown that probiotics help maintain digestive health (through different mechanisms), and that is why experts5 agree that they can be considered as probiotics6. Some of these bacterial species can also be found in a range of foods (such as yogurts and fermented milks) or supplements.
For further information on probiotics, why not check out this information sheet from the International Scientific Association for Probiotics and Prebiotics – ISAPP or the World Gastroenterology Organisation Global Guidelines on Probiotics and Prebiotics.


1 Gibson GR, Roberfroid MB. Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics. J Nutr. 1995 Jun;125(6):1401-12. PMID


2 Health and Nutritional Properties of Probiotics in Food including Powder Milk with Live Lactic Acid Bacteria, Report of a Joint FAO/WHO Expert Consultation on Evaluation of Health and Nutritional Properties of Probiotics in Food including Powder Milk with Live Lactic Acid Bacteria, Cordoba, Argentina, October 1-4,200


3 http://www.loveyourtummy.org/


4 Moheb Costandi, Microbes on Your Mind, Scientific American Mind 23, 32 (2012).


5 http://espcg.eu/wp-content/uploads/2013/09/ENGLISH-LEAFLET-ESPCG-2013-Consensus-Guidelines-on-Probiotics.pdf


6 http://www.gutmicrobiotaforhealth.com/definition-probiotics-twelve-years-later-6455