Synbiotic intervention with Bifidobacterium bifidum and prebiotics reduces enterohemorrhagic Escherichia coli colonization.

2026-02
Letters in applied microbiology 79(2)

PubMed: 41636800
DOI: 10.1093/lambio/ovag019

Study Design

Population: murine infection model
Methods: integrated strategy of in vitro screening followed by in vivo validation; ten prebiotics screened for promoting B. bifidum proliferation and acetate production, with murine infection model testing B. bifidum alone, inulin alone, and the combination of IMO and B. bifidum against EHEC

This study evaluated the protective effect of combining Bifidobacterium bifidum with the prebiotics inulin and isomalto-oligosaccharides against enterohemorrhagic Escherichia coli infection and investigated the underlying mechanisms, using an integrated strategy of in vitro screening followed by in vivo validation. Among ten prebiotics screened, IMO and inulin were identified as optimal for promoting B. bifidum proliferation and acetate production (>2.5-fold), with IMO further enhancing bacterial adhesion to Caco-2 cells (four-fold). In a murine infection model, B. bifidum alone reduced total intestinal EHEC colonization, whereas inulin alone was ineffective. The combination of IMO and B. bifidum markedly suppressed EHEC colonization, particularly in the colon (five-fold reduction), while inulin provided no added benefit. Although fecal acetate levels were elevated in synbiotic groups, no linear correlation with EHEC clearance was observed, suggesting that protection may rely on mechanisms other than bulk acetate production-such as localized metabolite delivery or microbial ecological interactions. These findings demonstrate that an IMO-based synbiotic can effectively limit EHEC colonization through multifactorial modulation of the gut ecosystem. The presented strategy offers a rational framework for designing synbiotics to prevent foodborne infections.

Research Insights

Supplement	Dose	Health Outcome	Effect Type	Effect Size	Source
Bifidobacterium bifidum	—	Reduced Enterohemorrhagic Escherichia coli Colonization	Beneficial	Moderate	View source In a murine infection model, B. bifidum alone reduced total intestinal EHEC colonization, whereas inulin alone was ineffective. The combination of IMO and B. bifidum markedly suppressed EHEC colonization, particularly in the colon (five-fold reduction)