Effect of Five Dietary Emulsifiers on Inflammation, Permeability, and the Gut Microbiome: A Placebo-controlled Randomized Trial.

Abstract

Background & aims: Dietary emulsifier consumption might promote intestinal inflammation, eventually leading to inflammatory bowel diseases. However, human data are scarce and involve a limited number of emulsifiers. We studied the effects of an emulsifier-free diet (EFD) and specific emulsifier supplementation.

Methods: Sixty healthy participants followed an EFD for 2 weeks. Then, using a randomized placebo-controlled trial design, participants continued an EFD for 4 weeks with the addition of either carboxymethyl cellulose, polysorbate-80, carrageenan, soy lecithin, native rice starch, or no additives administered through brownies. Effects on cardiometabolic markers, gut microbiota, intestinal inflammation, and permeability were explored.

Results: After 2 weeks of an EFD, cholesterol levels decreased (P = .00006). Under emulsifier supplementation, alpha diversity remained stable, yet microbial composition was affected by treatment and visit. Compared with placebo, concentrations of all short chain fatty acids were lower in those consuming carboxymethyl cellulose, which was mirrored by other emulsifiers, although not all reached significance. No differences in fecal calprotectin, C-reactive protein, serum lipopolysaccharide-binding protein, cholesterol levels, or other metabolic markers were observed between placebo and emulsifiers at the end of the intervention. Serum inflammatory and cardiometabolic proteins remained unchanged. In individuals consuming carrageenan, transcellular intestinal permeability increased (P = .04) compared with baseline.

Conclusion: In this double-blind placebo-controlled exploratory trial, emulsifier supplementation lowered short chain fatty acid concentration compared with placebo. Emulsifier supplementation did not impact intestinal or systemic inflammation or metabolic endpoints. Cholesterol levels decreased after 2 weeks of an EFD. These results point towards potential intestinal benefits of limiting dietary emulsifiers in the diet, requiring further investigation.

Clinicaltrials: gov, Number: NCT06552156.