Recombinant MAM from Faecalibacterium duncaniae exhibits a protective effect in DNBS-induced colitis.

Recombinant MAM (R-MAM) was successfully produced and purified under denaturing conditions, but could not be obtained in a non-aggregated form.

• Despite numerous attempts, a non-aggregated R-MAM could not be obtained.
• The authors concluded that 'the R-MAM used here is partly or totally denatured.'
• R-MAM was produced using recombinant expression and purified under denaturing conditions.
• This represents the first time purified MAM has been evaluated directly in vitro or in intestinal inflammation models.

R-MAM induced an anti-inflammatory cytokine profile in human intestinal epithelial cells (HT-29) in vitro.

• In vitro assays were conducted using HT-29 human intestinal epithelial cells.
• R-MAM confirmed 'the ability of MAM to induce an anti-inflammatory cytokine profile.'
• This constitutes the first direct demonstration of purified MAM's anti-inflammatory activity in a cell-based assay.
• Prior studies had relied on bacterial supernatants, synthetic peptides, or DNA delivery systems rather than purified protein.

R-MAM induced an anti-inflammatory cytokine profile in peripheral blood mononuclear cells (PBMCs) in vitro.

• PBMCs were used alongside HT-29 cells to assess anti-inflammatory activity.
• Results confirmed MAM's ability to induce an anti-inflammatory cytokine profile in immune cells.
• These in vitro findings were obtained with a partly or totally denatured form of R-MAM.
• The activity was observed despite the aggregated/denatured state of the protein.

Oral administration of R-MAM significantly prevented weight loss in a DNBS-induced colitis murine model.

• The colitis model used was dinitrobenzene sulfonic acid (DNBS)-induced colitis in mice.
• R-MAM was administered orally to mice in the colitis model.
• Weight loss, a key macroscopic indicator of inflammation, was significantly prevented by R-MAM treatment.
• This represents the first in vivo evaluation of purified MAM protein in an intestinal inflammation model.

Oral administration of R-MAM reduced colon weight and thickness in DNBS-induced colitis mice.

• R-MAM treatment significantly reduced colon weight in the DNBS-induced colitis model.
• R-MAM treatment significantly reduced colon thickness in the DNBS-induced colitis model.
• Colon weight and thickness are described as 'key macroscopic indicators of inflammation.'
• These protective effects were observed following oral administration of the denatured/aggregated R-MAM.

MAM from Faecalibacterium duncaniae A2-165 is identified as a key effector molecule whose depletion is linked to inflammatory bowel disease (IBD).

• MAM is described as 'a key effector of the next-generation probiotic Faecalibacterium duncaniae A2-165.'
• Depletion of F. duncaniae in the gut microbiota is 'strongly linked to inflammatory bowel disease (IBD) and other conditions.'
• Prior to this study, direct anti-inflammatory effects of purified MAM had never been evaluated in vitro or in intestinal inflammation models.
• Previous studies relied on bacterial supernatants, synthetic peptides, or DNA delivery systems, 'each with inherent limitations.'