Inflammatory bowel disease (IBD) affects the gut microbiome and metabolome. Curcumin, from turmeric, may be of benefit in some patients through action on the gut microbiome. Curcumin produces changes to bile acid secretion, and has a variety of direct effects on bacteria. Faeces release Faecal Volatile Organic Metabolites (VOMs), which partly reflect the gut microbiome. The aim of the study was to investigate the effects of turmeric on the VOMs in healthy individuals.Methods
5 participants were enrolled in a before-during-after pilot study, in which they were asked to take a turmeric-free diet and then to consume 1.6 g of turmeric daily for 5 days. Faecal samples were collected at baseline, after 5 days of turmeric ingestion, and again 5 days after this, and frozen immediately. The samples were analysed by an investigator blinded using gas chromatography mass spectrometry. Analytes were identified using AMDIS software and compared using Metaboanalyst software: ANOVA, PCA, PLSADA, and Heatmap were employed.Results
ANOVA yielded 0 significant features. For most of the VOMs found between the comparison groups, p>0.05. Both PCA and PLSADA failed to show any separation by group. Heatmap analysis did not show any pattern in the abundance of VOMs. VIP scores showed a decrease in the abundance of propanoic acid and methyl propionate in the intervention samples when compared to baseline and post-turmeric consumption. The box plots created from raw data in Figure 1 & 2 demonstrated lower median abundances of intervention samples as compared to comparison groups. The study was underpowered to demonstrate significant change.Conclusions
This pilot study illustrates that two VOMs appears to become less abundant when turmeric is consumed: both appear related to propionibacteria metabolism. Studies in patients with IBD are warranted.