Omega-3 fatty acids may help increase colonic microbiota diversity

Creating a colonic environment that reduces proinflammatory processes has important implications in promoting health and treating certain diseases.

Because the composition of the intestinal microbial community is thought to play an important role in modulating colonic inflammation, a better understanding of the dynamics between diet and intestinal microbiome diversity is important.  Whereas most studies quantify the intestinal microbiota in excreted stool and within the hollow cavity of the colon, bacteria adhering to the colon lining have been shown to differ.  Thus, studies that utilize comprehensive colonic sampling may yield different results in terms of the relation between diet and gut microbiota diversity.

A recent study by Dr. Zora Djuric (University of Michigan) and colleagues (Penn State Health) explored the role of the colonic bacterial microbiome in the anti-inflammatory effects of omega-3 fatty acids supplementation on both colon biopsy samples and colon luminal brushings. A total of forty-seven healthy adults provided colon lining biopsy samples and colon luminal brushings before and after 12-wk of dietary supplementation with personalized amounts of omega-3 fatty acids.  Changes in colonic bacterial diversity were used to predict decreased concentrations of prostaglandin E₂, a proinflammatory hormone-like substance that is linked with increased risk of colon cancer. Colonic lining biopsy samples and a stool brushing sample near the biopsy sites were obtained at baseline and after 12 weeks of omega-3 fatty acid supplementation

The study, published in the July 2019 issue of The Journal of Nutrition, found that dietary supplementation with omega-3 fatty acids increased the dissimilarity between the microbiome in luminal brushings and colon biopsy samples post-supplementation.

Increases in diversity of the bacteria in the luminal brushing samples, but not in the biopsy samples, were significant predictors of lower colonic proinflammatory concentrations.  The researchers concluded that, although dietary supplementation with omega-3 fatty acids had little effect on intestinal bacteria, an increase in diversity in the luminal brushings significantly predicted reductions in colonic prostaglandin E₂ concentrations. Thus, it is possible that the luminal bacteria are more susceptible to dietary changes than bacteria associated with the colon lining.

Reference Djuric A, Bassis CM, Plegue MA, Sen A, Turgeon DK, Herman K, Young VB, Brenner DE, Ruffin M. Increases in Colonic Bacterial Diversity after w-3 Fatty Acid Supplementation Predict Decreased Colonic Prostaglandin E₂ Concentrations in Healthy Adults. The Journal of Nutrition, Volume 149, Issue 7, July 2019, Pages 1170–1179, https://doi.org/10.1093/jn/nxy255

Calder PC. Is Increasing Microbiota Diversity a Novel Anti-Inflammatory Action of Marine n-3 Fatty acids? The Journal of Nutrition, Volume 149, Issue 7, July 2019, Pages 1102–1104, https://doi.org/10.1093/jn/nxz043