DOP86 FOod Additives on the Mucosal barrier study (FOAM): Effect of five emulsifiers on inflammation, intestinal permeability, and the microbiome: preliminary results

Abstract

Abstract Background Common emulsifiers are associated with intestinal inflammation and are therefore excluded in new dietary therapeutic strategies in inflammatory bowel disease. Human data are scarce and involve a limited number of emulsifiers. We aimed to investigate the effect of five different emulsifiers on systemic and intestinal inflammation, intestinal permeability, and the gut microbiome. Methods We recruited 60 healthy volunteers to a 7-week double-blind placebo controlled randomized trial. After 1 week of recording their habitual diet (baseline), participants followed an emulsifier-free diet (EFD) for 6 weeks, starting at baseline. After 2 weeks, participants combined the EFD with 3 daily brownies that contained either 2.75 g carboxymethyl cellulose, 1.350 mg polysorbate-80, 380 mg carrageenan, 3.55 g soy lecithin, or 8.72 g native rice starch, or no additives (placebo) for a period of 4 weeks. Anthropometric measurements and bio samples were taken at baseline, week 2 and week 6. Blood samples were collected for routine tests, LPS-binding ELISAs, and serum proteomics using the Olink Target 96 Inflammation and Cardiometabolic panels. Stool samples were collected for analysis of the microbiota (16S rRNA sequencing), short chain fatty acids (Gas Chromatography – Mass Spectrometry (GC-MS)), and faecal calprotectin (FC) analysis. Urine samples were collected following the 2-hour lactulose mannitol ratio protocol to measure intestinal permeability (using GC-MS). Results Of the 60 healthy volunteers, 2 were excluded due to NSAID use. Median (IQR) age was 25.5 years (23.0-33.0), median BMI was 22.7 kg/m2 (21.2-25.6) and 19.0% were male. There was a median weight loss of 0.1 kg (p=7.6*10-4, paired Wilcoxon, unadjusted p-value). At week 6 and week 2, FC decreased significantly compared to baseline (p= 4.69*10-4, and p=2.81*10-4 respectively, paired Wilcoxon, unadjusted p-value, Table 1 and Figure 1A). No significant increase in FC was noted after consumption of any emulsifier during the trial. In the placebo arm, faecal acetic acid concentration was increased at week 2 (p=0.04). Compared to baseline, there was an increase in both acetic acid and propionic acid concentration (p=0.006 and p=0.04 respectively, paired Wilcoxon, unadjusted p-value, Figure 1B) in the same arm at week 6. Conclusion In this double-blind placebo controlled randomized trial faecal acetic and propionic acid increased in the placebo arm, but did not after consumption of any of the emulsifiers. FC did not increase after consumption of any emulsifier. Pending analysis will shed light on the effect of an EFD and distinct emulsifiers on the serum proteome, intestinal permeability and gut microbial changes.