Specific Dietary Preferences Are Linked to Differing Gut Microbial Metabolic Activity in Response to Dark Chocolate Intake

Systems biology approaches are providing novel insights into the role of nutrition for the management of health and disease. In the present study, we investigated if dietary preference for dark chocolate in healthy subjects may lead to different metabolic response to daily chocolate consumption. Using NMR- and MS-based metabolic profiling of blood plasma and urine, we monitored the metabolic response of 10 participants stratified as chocolate desiring and eating regularly dark chocolate (CD) and 10 participants stratified as chocolate indifferent and eating rarely dark chocolate (CI) to a daily consumption of 50 g of dark chocolate as part of a standardized diet over a one week period. We demonstrated that preference for chocolate leads to different metabolic response to chocolate consumption. Daily intake of dark chocolate significantly increased HDL cholesterol by 6% and decreased polyunsaturated acyl ether phospholipids. Dark chocolate intake could also induce an improvement in the metabolism of long chain fatty acid, as noted by a compositional change in plasma fatty acyl carnitines. Moreover, a relationship between regular long-term dietary exposure to a small amount of dark chocolate, gut microbiota, and phenolics was highlighted, providing novel insights into biological processes associated with cocoa bioactives

Bar plots describing metabolite variations in the study population stratified in four quartiles according to visceral fat adiposity (intraperitoneal fat) at V2.

<p>Statistical significance is reported in Table S3. Key: PC-O, 1-O-alkyl-2- acylglycerophosphocholines. Assignment of PC-O species is made on the assumption that only even numbered carbon chains are present. A potential overlap between PC species containing odd-chain fatty acids and even-chained PC-O species cannot be excluded with low mass resolution.</p

Plot describing metabolite importance and robustness in predicting visceral fat adiposity as assessed by Random forest analysis using metabolic data collected at V0 and V2.

<p>Visceral adiposity was associated with increasing concentrations of amino acids (glutamine, leucine/isoleucine, phenylalanine and tyrosine), lysophosphatidylcholine LPC 24∶0 and diacyl phospholipids (PC 30∶0, PC 34∶4). In addition, visceral adiposity was marked by a depletion in ether lipid species PC<i>-O</i> 36∶3, PC<i>-O</i> 40∶3, PC<i>-O</i> 40∶4, PC<i>-O</i> 40∶6, PC<i>-O</i> 42∶2, PC<i>-O</i> 42∶3, PC<i>-O</i> 42∶4, PC<i>-O</i> 44∶3, PC<i>-O</i> 44∶4, PC<i>-O</i> 44∶6, and two diacyl phosphocholines (PC 42∶0 and PC 42∶2). To reflect the weight of the selected biomarkers in the classification of visceral adiposity, a pooled mean decrease of accuracy for each compound was calculated from 10000 forest generations. Higher variable importance corresponds to higher values of pooled mean decrease in accuracy. Key: IPVF, intraperitoneal fat volume; LPC, Lysophosphatidylcholines; PC, Phosphatidylcholines; PC-O, 1-O-alkyl-2- acylglycerophosphocholines; Ratio1, intraperitoneal/subcutaneous fat ratio; Ratio 2, intraperitoneal/abdominal fat ratio. Assignment of PC-O species is made on the assumption that only even numbered carbon chains are present. A potential overlap between PC species containing odd-chain fatty acids and even-chained PC-O species cannot be excluded with low mass resolution.</p

Metabolite variations across subjects stratified according to intraperitoneal/abdominal fat ratio.

<p>NB: Blood plasma metabolites highlighted by multivariate analyses are reported as mean values ± SD. Key: Qi: data for population quartile i according to intraperitoneal/abdominal fat ratio. 12-HETE, 12-hydroxy-eicosatetraenoic acid; 15-HETE, 12-hydroxy-eicosatetraenoic acid; 9-HODE, 9-Hydroxy-10,12-octadecadienoic acid; AA, arachidonic acid; LPC, Lysophosphatidylcholines; PC, Phosphatidylcholines; PC-O, 1-O-alkyl-2- acylglycerophosphocholines; SM, Sphingomyelines; SM-OH, Hydroxy-Sphingomyelin.</p>*<p>Assignment of PC-O species is made on the assumption that only even numbered carbon chains are present. A potential overlap between PC species containing odd-chain fatty acids and even-chained PC-O species cannot be excluded with low mass resolution.</p

Metabolic Phenotyping of the Crohn's Disease-like IBD Etiopathology in the TNF^ΔARE/WT Mouse Model

The underlying biochemical consequences of inflammatory bowel disease (IBD) on the systemic and gastrointestinal metabolism have not yet been fully elucidated but could help to better understand the disease pathogenesis and to identify tissue-specific markers associated with the different disease stages. Here, we applied a metabonomic approach to monitor metabolic events associated with the gradual development of Crohn's disease (CD)-like ileitis in the TNF^ΔARE/WT mouse model. Metabolic profiles of different intestinal compartments from the age of 4 up to 24 weeks were generated by combining proton nuclear magnetic resonance (¹H NMR) spectroscopy and liquid chromatography–mass spectrometry (LC–MS). From 8 weeks onward, mice developed CD similar to the immune and tissue-related phenotype of human CD with ileal involvement, including ileal histological abnormalities, reduced fat mass and body weight, as well as hallmarks of malabsorption with higher energy wasting. The metabonomic approach highlighted shifts in the intestinal lipid metabolism concomitant to the histological onset of inflammation. Moreover, the advanced disease status was characterized by a significantly altered metabolism of cholesterol, triglycerides, phospholipids, plasmalogens, and sphingomyelins in the inflamed tissue (ileum) and the adjacent intestinal parts (proximal colon). These results describe different biological processes associated with the disease onset, including modifications of the general cell membrane composition, alteration of energy homeostasis, and finally the generation of inflammatory lipid mediators. Taken together, this provides novel insights into IBD-related alterations of specific lipid-dependant processes during inflammatory states

Statistically significant Spearman correlation map between body fat composition parameters and clinical measures (95% confidence interval).

<p>Log₁₀ values of IPVF, VAT/SAT, VAT/total abdominal fat were strongly associated with HOMA-IR (r = 0.39, p = 0.015; r = 0.56, p<0.001; r = 0.55, p<0.001) and fasting insulin (r = 0.35, p = 0.0275; r = 0.49, p = 0.0017; r = 0.48, p = 0.0020). Strong associations were observed with ALAT (r = 0.39, p = 0.0128; r = 0.37, p = 0.0175; r = 0.38, p = 0.0167) and ALAT/ASAT ratio (r = 0.44, p = 0.0044; r = 0.35, p = 0.0268; r = 0.35, p = 0.0302). IPVF and Log₁₀ values of IPVF correlated with waist (r = 0.55, p<0.001; r = 0.35, p = 0.04) and waist/hip ratio (r = 0.69, p<0.001; r = 0.52, p = 0.0017), but not Log₁₀ values of VAT/SAT and VAT/total abdominal fat. NB: Blue denotes negative correlation, orange denotes positive correlation, and black denotes no correlation.</p

Descriptive statistics of subjects stratified according to intraperitoneal/abdominal fat ratio.

<p>Key: Qi: data for population quartile i according to intraperitoneal/abdominal fat ratio. BMI = body mass index, HDL-C =  high density lipoprotein cholesterol, homeostasis model assessment of insulin resistance =  HOMA-IR, LDL-C =  low density lipoprotein cholesterol, TG =  triglycerides, MAP =  mean arterial blood pressure, ALAT =  alanine aminotransferase, ASAT =  aspartate aminotransferase, GGT =  gamma-glutamyl transpeptidase, NEFAs = non esterified fatty acids. Data are reported as mean values ± SD.</p

Insulin and glucose response to oral glucose tolerance test according to intraperitoneal/abdominal fat ratio.

<p>NB: Values are reported as mean values ± SD. Key: Qi: data for population quartile i according to intraperitoneal/abdominal fat ratio.</p