Omega 3 boosts gut microbiome diversity

11 Sep 2017 --- Taking omega 3 as part of a healthy diet with plenty of fiber and probiotic foods can improve the diversity of the gut microbiome. This is according to a new study by researchers at the University of Nottingham and King’s College London.

The group of scientists, which includes experts from the School of Medicine at Nottingham, examined the gut microbiome of a large cohort of middle-aged and elderly women. They tested the diversity and abundance of “good” bacteria against their intake of omega 3 fatty acids – found in fish oil – and their blood serum levels of omega 3 fatty acids.

The study, published in Scientific Reports, found that the women who had a higher dietary intake of omega 3 and higher serum levels had a more diverse gut microbiome. A more diverse microbiome is associated with a number of health benefits, including lower risk of diabetes, obesity and inflammatory gut diseases like colitis or Crohn’s, according to the University of Nottingham press release.

“In general the advice to the public is to eat a healthy balanced diet,” Dr. Ana Valdes, who is affiliated to the NIHR Nottingham Biomedical Research Centre, tells NutritionInsight. “Higher levels of omega 3 [can be attained by] eating fish regularly.”

Largest study to date
The results of the study come at a time when gut health is becoming increasingly prominent. “The human gut is receiving a lot of attention in medical research as it is increasingly linked to a wide variety of health issues,” Valdes says. “Our digestive systems are home to trillions of microbes, most of which are beneficial in that they play a vital role in our digestion, immune system and even regulate our weight.”

“Our study is the largest to date to examine the relationship between omega 3 fatty acids and the composition of the gut microbiome,” Valdes reports. “This cohort of 876 volunteer women had previously been used to investigate the human genetic contribution to the gut microbiome in relation to weight gain and disease. We examined their food intake of omega 3 fatty acids using food frequency questionnaires and found these data, together with their serum levels of omega 3, were strongly associated with the diversity and number of species of healthy bacteria in the gut.”

“We also found that specific bacteria that have been linked to lower inflammation and lower risk of obesity are increased in people who have a higher intake of omega 3 fatty acids,” adds Dr. Cristina Menni from King’s College London. “We further explored how this related to compounds in feces and found that, in addition to fish protein and omega 3, high levels of omega 3 in blood are correlated with high levels of a compound called N-carbamylglutamate (NCG) in the gut. This compound has been shown in animals to reduce oxidative stress in the gut. We believe that some of the good effects of omega 3 in the gut may be due to the fact that omega 3 induces bacteria to produce this substance.”

Growing body of evidence
Previous wider research has observed positive effects on health from omega 3 fatty acids on insulin resistance in diabetes, hypertension (high blood pressure), arthritis, thrombosis (blood clots), some cancers and cognitive decline. This new study has added weight to the growing global body of evidence to suggest that omega 3 also appears to improve the gut microbiome both in its diversity and composition.

“Omega 3 supplements are considered generally safe and doses of up to 1g per day do not increase the risk of bleeding, but still they may not be for everyone and people should not take high doses of any supplement without consulting their doctor,” Valdes says of supplement use to increase gut benefits. “Having said that, omega 3 supplements are used for other indications already, and our data suggest that they could also be considered to improve the composition of the gut microbiome, which in itself may have other benefits. For example, a separate study published a few months ago [showed] that low microbiome diversity correlates with higher long-term weight gain.”

When it comes to further studies into omega 3 and the gut microbiome that would be useful, Valdes gives a specific example: “An interventional study giving a placebo, a lower and a higher dose of omega 3 supplements to individuals with low microbiome diversity (i.e., a not very healthy gut microbiome). Seeing after four weeks how the microbiome has improved and testing other measures of gut inflammation in these people before and after the four weeks of omega 3 supplements.”

By Paul Creasy