Gut microbiome responses to dietary intervention with hypocholesterolemic vegetable oils

Abstract

Hypercholesterolemia is becoming a problem with increasing significance. Dietary vegetable oils may help to improve this condition due to presence of phytonutrients with potentially synergistic cholesterol-lowering effects. The objective of this 8-week double-blinded randomized clinical trial was to investigate the effects of consuming 30 g of two different blended cooking oils, rich in omega-3 alpha-linolenic acid and phytonutrients, or refined olive oil on the intestinal microbiota in 126 volunteers with borderline hypercholesterolemia. Multi-factor analysis of relationships between the gut microbiota composition at various taxonomic ranks and the clinical trial parameters revealed the association between beneficial effects of the dietary intervention on the blood lipid profile with abundance of Clostridia class of the gut microbiota. This microbiota feature was upregulated in the course of the dietary intervention and associated with various plasma markers of metabolic health status, such as Triglycerides, Apolipoprotein B and Total Cholesterol to HDL ratio in a beneficial way. The relative abundance of a single species—Clostridium leptum—highly increased during the dietary intervention in all the three study groups. The oil blend with the highest concentration of omega-3 PUFA is associated with faster and more robust responses of the intestinal microbiota, including elevation of alpha-diversity. Butyrate production is being discussed as a plausible process mediating the observed beneficial influence on the plasma lipid profile. Causal mediation analysis suggested that Clostridium genus rather than the higher rank of the phylogeny—Clostridia class—may be involved in the diet-induced improvements of the blood lipid profile.

The hallmarks of dietary intervention-resilient gut microbiome

“…Since the estimate of the AGN from 16S rRNA data might be quite imprecise, we performed additional validation of partial correlation results using “shotgun” metagenomic dataset related to a dietary intervention 53 . The intervention included 126 subjects who consumed blended cooking oils or refined olive oil for 8 weeks (three time points were collected: baseline, 2 weeks and 8 weeks).…”

“…One “shotgun” metagenomic dataset 53 described microbiome changes during the intervention including intake of blended cooking oils or refined olive oil for 8 weeks ( N = 126 subjects, 3 time points); it was used for: validation of response associations with alpha diversity, AGN and B:F; validation of AGN calculation. …”

“…The “shotgun” dataset used for validation of partial correlation analysis results 53 was downloaded from the NCBI Sequence Read Archive (PRJNA728374) ( N = 378 samples). The reads were processed using KneadData ( https://huttenhower.sph.harvard.edu/kneaddata/ ) and MetaPhlAn3 software 67 with “-t rel_ab_w_read_stats” option to obtain the read counts.…”

“…The partial correlation network from five components (including response potential) was constructed in the same way. For this analysis, we performed a validation using a “shotgun” dataset described above 53 .…”

Beneficial Effects of Anti-Inflammatory Diet in Modulating Gut Microbiota and Controlling Obesity

“…Another study on 126 participants with borderline hypercholesterolemia indicated that during the dietary intervention, the relative abundance of a single species, Clostridium leptum , increased dramatically, and along with that, various plasma markers of the metabolic health status improved, including apolipoprotein B, triglyceride, and the ratio of total cholesterol to HDL. In this study, butyrate production was discussed as a possible process for improving blood lipid profile [ 134 ].…”