While exerting their metabolic activities in the gastrointestinal milieu, probiotics impact the host well-being by boosting immunity, treating metabolic disorders, and modulating microbiota and metabolome. Due to the high incidence of gluten-based disorders, the present work aims to deeply explore the metabolism of two selected microbial consortia (MCs) during gluten digestion under simulated gastrointestinal conditions. Featured by high protease and peptidase activity, both MCs accounted for different lactic acid bacteria and Bacillus strains that were combined with two commercial protease enzymes. Gluten substrates were used as purified extracts, white and whole wheat breads. Control samples, instead, relied onto the microbial enzyme lack. Twenty-four hours of simulated digestion were sufficient to completely hydrolyze gluten in one of the two MC-containing experimental sets, and the relative 48 h-digested extract did not alter the cytokine expression in duodenal biopsies from celiac disease (CeD) patients. When digested samples were assayed for antioxidant and phytase activities, microbial enzymes demonstrated to significantly improve both ABTS and DPPH values and to decrease the phytic acid concentration. The inspection of the free amino acid profiles allowed for distinguishing the two MCs, whereas the detection of a heterogeneous panel of volatile organic compounds supported the presence/activity of microbial enzymes without statistically significant differences between MCs. As functional contribution, digested extracts with MCs also proved to reduce the inflammatory cytokine concentrations in cell lines exposed to lipopolysaccharide trigger. Therefore, in line with studies exploring novel adjuvant therapies, the present innovative probiotic consortium featured by high gluten-hydrolyzing metabolism also showed the capability to improve various parameters usually found to be altered in patients affected by gluten-based disorders or CeD.

Nowadays, IBD-patient therapies are mainly based on corticosteroid, thiopurine, and immunomodulator treatments. Patients with active disease, that do not respond to corticosteroid and/or thiopurine treatment, can switch to the usage of the chimeric monoclonal antibody infliximab (IFX). However, to date, no treatment appeared to be conclusive in lowering the incidence of IBD relapses. With the aim to increase the effectiveness of IFX treatment, we combined it with an adjuvant purple corn supplementation enriched in anthocyanins. IBD-patients were enrolled before they underwent to the IFX-infusion, and they were allocated in two different study arms. Patients in the intervention-arm followed a dietary supplementation with purple corn water-soluble extract, whereas control patients had a daily consumption of red fruit tea. 16S rDNA gene-sequencing and high-resolution mass-spectrometry metabo-lipidomics analyses were conducted on stool and sera samples, respectively.

As a result, the experimental intervention mainly affected the serum metabolome of IBD-patients by decreasing the concentration of specific lipids. Focusing on IBD patient annotated taxa, a significant decrease in Lactobacillus and Bifidobacterium relative abundances was found.

As far as it concerns the ulcerative colitis patient subset, the experimental intervention led to a decrease in Alistipes and Erysipelotrichaceae UCG-003 genus abundances and a concomitant Parabacteroides increase. On the contrary, after treatment, Crohn’s disease patients did not exhibit metataxonomics differences at the genus level.

At the end of the treatment that led to a reshaped microbiota community, the gathered data paves the way for the usage of a specifically designed probiotic supplementation as a valuable strategy for IBD-patients under IFX infusion.