The Imbalance between n-6/n-3 Polyunsaturated Fatty Acids and Inflammatory Bowel Disease: A Comprehensive Review and Future Therapeutic Perspectives

Abstract

Eating habits have changed dramatically over the years, leading to an imbalance in the ratio of n-6/n-3 polyunsaturated fatty acids (PUFAs) in favour of n-6 PUFAs, particularly in the Western diet. Meanwhile, the incidence of inflammatory bowel disease (IBD) is increasing worldwide. Recent epidemiological data indicate the potential beneficial effect of n-3 PUFAs in ulcerative colitis (UC) prevention, whereas consumption of a higher ratio of n-6 PUFAs versus n-3 PUFAs has been associated with an increased UC incidence. The long-chain dietary n-3 PUFAs are the major components of n-3 fish oil and have been shown to have anti-inflammatory properties in several chronic inflammatory disorders, being involved in the regulation of immunological and inflammatory responses. Despite experimental evidence implying biological plausibility, clinical data are still controversial, especially in Crohn’s disease. Clinical trials of fish-oil derivatives in IBD have produced mixed results, showing beneficial effects, but failing to demonstrate a clear protective effect in preventing clinical relapse. Such data are insufficient to make a recommendation for the use of n-3 PUFAs in clinical practice. Here, we present the findings of a comprehensive literature search on the role of n-3 PUFAs in IBD development and treatment, and highlight new therapeutic perspectives.

The Influence of Nutrients on Inflammatory Bowel Diseases

“…Numerous studies prove that o-3 fatty acids and their appropriate ratio to o-6 can favourably reduce the inflammatory markers in the large intestine. erefore, many studies also indicate the beneficial effect of o-3 above all in UC [28,29]. However, fats (in total) consumed in excess may increase the risk of both CD and UC [30].…”

A possible link between polyunsaturated fatty acids and uremic toxins from the gut microbiota in hemodialysis patients: A hypothesis

“…Therefore, in contrast to the plasma fatty acids that reflect the recent dietary intake, the fatty acids incorporated into erythrocytes indicate the balance of these biomarkers for at least 3-4 months and, consequently, the habitual diet. 53 Although Sun et al 54 reported that the level of PUFAs from habitual dietary intake has a stronger relationship with the level of fatty acids measured in erythrocyte membranes than with those measured in the plasma, the concordance level between them is good. Therefore, in concordance with Sertoglu et al, 55 who observed that erythrocyte membrane fatty acids were superior to plasma fatty acids as biomarkers in patients with type 2 diabetes mellitus, we demonstrated in this study that erythrocyte fatty acids are associated with the stage of CKD in HD patients, as estimated by uremic toxins.…”

“…CKD is a chronic disease in which the continuous synthesis of uremic toxins and increased plasma uremic toxins directly reflect kidney failure. Therefore, in contrast to the plasma fatty acids that reflect the recent dietary intake, the fatty acids incorporated into erythrocytes indicate the balance of these biomarkers for at least 3–4 months and, consequently, the habitual diet . Although Sun et al reported that the level of PUFAs from habitual dietary intake has a stronger relationship with the level of fatty acids measured in erythrocyte membranes than with those measured in the plasma, the concordance level between them is good.…”

Assessment of Fatty Acid Desaturase (Fads2) Structure-Function Properties in Fish in the Context of Environmental Adaptations and as a Target for Genetic Engineering

“…Numerous global and national health agencies and associations and government bodies have produced many recommendations for EFA intake for a healthy human diet through fish consumption. With the advent of molecular and genetic technologies, there appeared much evidence that a balanced abundance of EFA is a prerequisite for health and disease prevention in humans [19][20][21]. Meeting the dietary demands of a burgeoning human population with a correct dietary balance of EFA and at levels required for normal health and development has become a major challenge.…”