Gut microbiota and omega-3 fatty acids


The term microbiota refers to the entire population of microorganisms that colonizes a particular location, and includes bacteria, viruses, fungi and other microorganisms. Gut microbiota (formerly called gut flora) is the name of the microbe population living in our intestine. Our gut microbiota contains tens of trillions of microorganisms (more than stars in the Milky Way), including at least 1000 different species of known bacteria, and it can, in total, weigh up to 2 kg. A healthy and balanced gut microbiota is key to ensuring a good health condition; it helps the body to digest certain foods that the stomach and small intestine have not been able to digest, to product some vitamins, and to combat aggressions from other microorganisms. Besides, it plays an important role in the immune system, performing a barrier function. To understand the importance of the microbiota, it is sufficient to know that the sum of the genes of this microorganisms (which have many different functions in our organism) outnumber the genes in our genome by about 100 to 1. The set of all our microbes’ genes receives the name of microbiome.

One third of our gut microbiota is common to most people, while two thirds are specific to each one of us. Its development starts at birth, and its composition evolves throughout our entire life, as a result of the influence of different factors, including age, diet, antibiotics, and environmental exposure to microorganisms.

There is a strong correlation between omega-3 fatty acids and microbiota composition (high circulating levels of omega-3 are associated with higher diversity) and there are some data suggesting that the effect of omega-3 on the gut microbiota may also play an important role in the effects of these acids on health.

Supplementation with omega-3 may be considered, along with prebiotic (which serve as “food” for beneficial bacteria) and probiotic (which help gut microbiota keep its balance, integrity and diversity) supplementation, as a good strategy aimed at improving the microbiome composition and diversity.


Menni C, Zierer J, Pallister T, et al. Omega-3 fatty acids correlate with gut microbiome diversity and production of N-carbamylglutamate in middle aged and elderly women. Sci Rep. 2017;11;7(1):11079.

Jandhyala SM, Talukdar R, Subramanyam C, et al. Role of the normal gut microbiota. World J Gastroenterol. 2015;21(29):8787-803.

Gut microbiota for health_ Gut Microbiota and Health Section of the European Society for Neurogastroenterology & Motility. Gut microbiota info. Disponible en:


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