Figure 4. Cross regulation of the microbiome with neutrophils at the gastrointestinal mucosa.

At the GI tract, microbiota play a key role in the regulation of neutrophil responses. Commensal microbiota generally engages immunoregulatory responses which inhibit excessive neutrophil infiltration. Pathogenic microbiota trigger neutrophil recruitment and activation at the GI tract. Neutrophils recruited by pathogens can exit into the lumen to mediate protection to the host. However, many pathogens have found ways to use neutrophil responses for their growth advantage and thus perpetuate neutrophil infiltration and activation for their benefit.