The study, published in Nature’s Scientific Reports, examined the gut microbiome of a large cohort of middle-aged and elderly women by comparing the diversity and abundance of ‘good’ bacteria against their intake of omega-3 fatty acids and their blood serum levels of omega-3 fatty acids.
Led by Dr Ana Valdes from the University of Nottingham, the team found that women who had a higher intake of omega-3 and a higher omega-3 index had more diverse gut microbiome – which is associated with a number of health benefits, including lower risk of diabetes, obesity and inflammatory gut diseases like colitis or Crohn’s.
“Our study is the largest to date to examine the relationship between omega-3 fatty acids and the composition of the gut microbiome,” said Valdes.
The team used data from a cohort of 876 volunteer women that 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.”
As a result, the team concluded that measures of omega-3 index and intake are significantly associated with microbiome composition independent of dietary fibre intake.
“These data suggest the potential use of omega-3 supplementation to improve the microbiome composition,” the authors said.
Microbiome data
The UK-based researchers analysed data from 876 twins with 16S microbiome data and DHA, total omega-3, and other circulating fatty acids.
They used food frequency questionnaire data to estimate dietary intake of omega-3 fatty acids.
Analysis showed that both total omega-3 and DHA serum levels were significantly correlated with microbiome alpha diversity after adjusting for confounders including dietary fibre intake and intake of probiotics.
“We found even stronger associations between DHA and 38 operational taxonomic units (OTUs), the strongest ones being with OTUs from the Lachnospiraceae family,” said the team.
Study co-author Dr Cristina Menni, from King’s College London, added that this family of bacteria that have been linked to lower inflammation and lower risk of obesity.
“We further explored how this related to compounds in faeces 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,” said Menni. “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,” she said.
Source: Scientific Reports
Published Online, Open Access, doi: 10.1038/s41598-017-10382-2
“Omega-3 fatty acids correlate with gut microbiome diversity and production of N-carbamylglutamate in middle aged and elderly women”
Authors: Cristina Menni, et al