Pear peel polyphenols protect against ulcerative colitis via coordinated modulation of gut microbiota and mucosal immunity.

Pear peel polyphenols markedly suppressed proinflammatory cytokine and enzyme expressions in LPS-stimulated RAW264.7 macrophages in vitro.

• The in vitro model used lipopolysaccharide (LPS) stimulation of RAW264.7 macrophages.
• PPP treatment resulted in marked suppression of proinflammatory cytokine expressions.
• Proinflammatory enzyme expressions were also suppressed by PPP treatment.

PPP significantly mitigated ulcerative colitis symptoms in dextran sulfate sodium (DSS)-induced colitis mice.

• The in vivo model used DSS-induced colitis in mice.
• PPP treatment significantly reduced UC symptoms in the mouse model.
• PPP suppressed serum inflammatory cytokine production in treated mice.
• PPP ameliorated histological damage in colon tissues of colitis mice.

PPP modulated gut microbiota by reshaping microbial diversity, enriching beneficial taxa, and suppressing proinflammatory taxa.

• PPP treatment reshaped overall microbial diversity in DSS-induced colitis mice.
• Beneficial taxa enriched by PPP included Akkermansia.
• Proinflammatory taxa suppressed by PPP included Bacteroides, Enterobacteriaceae, and Parabacteroides.

Proteomic analysis demonstrated that PPP modulated mucosal immunity by suppressing immunoglobulin-related molecules and attenuating antigen presentation pathways.

• PPP suppressed levels of immunoglobulin-related molecules including IgM, IgD, and IgA.
• PPP attenuated antigen presentation pathways involving major histocompatibility complex (MHC) class II molecules.
• PPP attenuated cluster of differentiation (Cd40) signaling as part of mucosal immune modulation.
• These findings were identified through proteomic analysis of colon tissues.

Pear peel is an edible component rich in diverse polyphenols with demonstrated bioactivity that enhances the nutritional and functional value of pears.

• Pear peel is described as often regarded as compromising the fruit's sensory quality despite being edible.
• Pear peel represents a valuable dietary source of health-promoting compounds within a whole food diet.
• The role of pear peel polyphenols in ulcerative colitis was previously underexplored.