Conjugated linoleic acid (CLA) as a functional food: Is it beneficial or not?

Conjugated Linolenic Acid (CLnA) vs Conjugated Linoleic Acid (CLA): A Comprehensive Review of Potential Advantages in Molecular Characteristics, Health Benefits, and Production Techniques

“…Previous studies have shown that the different isomers of CLnA mainly regulate antioxidant levels, HMG-CoA reductase, and FAS enzyme activity and related pathways primarily involving PPARs and SREBP-1 to maintain a healthy proportion of fatty acids or lipoproteins in the blood and tissues. The regulation of CLA mainly involves: (a) antioxidant effects-mediated repair of cardiovascular oxidative stress damage, (b) related anti-inflammatory regulation to reduce vascular endothelial dysfunction, platelet activation and thrombosis, (c) PPARs, SREBPs, and SCD1-mediated balance and homeostasis regulation of blood lipids and cholesterol, and (d) eicosanoic acid-mediated platelet aggregation and thrombosis regulation. ,, There are differences in the regulatory pathways of CLA isomers, such as t10, c12-CLA mainly regulates key enzymes related to gluconeogenesis, β-oxidation, and ketogenesis pathways, while c9, t11-CLA regulates anti-inflammatory heat shock proteins and proinflammatory macrophage migration inhibitory factor . Obviously, the regulatory mechanism of CLnA on CVD is largely similar to that of CLA, which also indicates that the dominance of their respective roles may depend on the sensitivity of metabolic pathways to isomers.…”

“…For example, c9, t11- isomer (rumenic acid) accounts for 75–95% of the CLA in ruminant meat and milk fat, and about 50% in vegetable oil, while t10, c12-CLA accounts for about 40% in vegetable oil CLA . The specific content and isomer ratio of CLA are closely related to factors such as biological species, age, season, diet, and feed additives. , Surprisingly, although CLnA exists naturally in the form of mixed isomers, the content of a single isomer is extremely abundant in different plant seed oils. For example, pomegranate seed oil contains as much as 80% PA and less than 4% of other CLnA isomers .…”

“…Among them, conjugated linoleic acid (CLA) and conjugated linolenic acid (CLnA), which have two and three conjugated double bonds, respectively, are widely recognized as highly bioactive functional lipid molecules. Although both of them have multiple positional and geometric isomers, only some isomers have been identified to have various physiological effects such as anticancer, anti-inflammatory, lipid reduction, diabetes and cardiovascular disease risk control, and immune regulation. − The current research reports on CLA are very comprehensive and detailed, while information related to CLnA is relatively scarce. Due to the similarity in molecular structure and larger conjugated system, CLnA is considered to have potential advantages over CLA in certain aspects.…”

“…However, as the efficacy and safety of CLnA have not been fully confirmed, it has not yet been approved for listing as a new food ingredient. As a functional food ingredient, the recommended dosage of CLA is 3.4–6 g/day, while the effective dosage of CLnA is generally considered to be 2–3 g/day. , Moreover, there is a possibility of mutual conversion between CLnA and CLA in the organism. , However, although CLA has demonstrated a wide range of physiological benefits, it also comes with some drawbacks or negative effects, such as insignificant clinical health benefits, as well as potential causes of liver steatosis, insulin resistance, reproductive system developmental damage, and increased risk of colorectal cancer . Even though CLnA has been also associated with a few negative aspects, such as high-dose induced oxidative stress and long-term intervention against high-density lipoprotein cholesterol, it is generally safe. , Therefore, it is of huge interest to know the advantageous characteristics of CLnA over CLA, thus discovering its potential application value and opening further research lines in the future.…”

A mutant fitness compendium in Bifidobacteria reveals molecular determinants of colonization and host-microbe interactions

“…While Bb strains generally lack the capability to utilize the same breadth of human milk oligosaccharides (HMOs) as Bifidobacterium infantis strains, they can utilize some HMOs such as lacto-N-tetraose (LNT) and lacto-N-neotetraose (LNnT) 23 and can cross-feed on monosaccharides released by other members of the gut microbiota 24,25 , including fucose. Bb strains produce indole-3-lactic acid 10 and conjugated linoleic acid 13 , both of which have been associated with positive impacts on host health 26,27 . Importantly, previous work demonstrated that Bb strain UCC2003 could be transformed at sufficiently high efficiency to create a transposon-insertion library 28 .…”