Sucralose and maltodextrin affect differently the gut microbiota of healthy individuals and IBD patients

Intestinal fibrosis is a long–term complication of inflammatory bowel diseases (IBD). Changes in microbial populations have been linked with the onset of fibrosis and some food additives are known to promote intestinal inflammation facilitating fibrosis induction. Most of these studies have been performed using murine models or healthy donors while the effects of food additives on intestinal microbiota of patients suffering from IBD is less understood. The aim of this work was therefore to determine how food additives affect intestinal microbiota of both healthy and “IBD” donors. Two food additives, sucralose (SUC) and maltodextrin (MDX), were tested in a short–term (72h) in vitro model of the human intestinal microbiota. Three groups of donors were investigated: healthy persons (H), patients in remission of IBD (R) and patients with an active period of IBD (A). Short-chain fatty acid production was assessed using SPME-GC/MS while the evolution of microbial populations positively or negatively correlated with health, inflammation and/or fibrosis was assessed using qPCR. MDX and SUC increased propionate and butyrate production in H and R donors. In addition, MDX increased butyrate in A donors and decreased the butyrate–producer genus Roseburia in H and R donors. Both, SUC and MDX decreased the beneficial bacteria F. prausnitzii in A donors. Moreover, in R and A donors, SUC and MDX decreased A. muciniphila. MDX promoted the growth of Enterococcus in H and R groups and Streptococcus in the three groups of donors, both genus being associated with intestinal inflammation. SUC induced increases of Escherichia/Shigella in H and Enterococcus in H and R groups. Ruminococcus, correlated with higher risk of fibrosis, was increased in the three groups of donors treated with MDX while SUC increased Ruminococcus only in IBD donors. Oscillospira, correlated with reduced risk of fibrosis, was decreased in the three groups of donors with MDX and in H and A donors with SUC. This study demonstrates how strongly the human microbiota can be affected by some food additives. In addition, to our knowledge, this is the first human in vitro study focusing on the impact of food additives on microbiota of IBD patients.