Prevotella histicola suppress olfactory bulb damage caused by LPS-induced rhinitis in mice

In rhinitis patients, nasal inflammation often precipitates olfactory dysfunction and, when prolonged, may reduce olfactory bulb volume and affect memory. To explore a treatment, we orally administered Prevotella histicola(P. histicola), known for its central nervous system anti - inflammatory capacity, to mice with lipopolysaccharide (LPS)-induced rhinitis. LPS nasal drip-induced rhinitis, Caused damage to the function of olfactory bulb neurons and activating microglia with elevated TNF-α levels. After P. histicola intervention, mice showed increased olfactory - related exploratory behavior, indicating improved olfactory function. Biochemically, there was an increase in tyrosine hydroxylase (TH) expression in the olfactory bulb, a rise in the proportion of inhibited spleen regulatory T cells with abundant IL - 10 secretion, a shift from pro - inflammatory M1 type to anti - inflammatory M2 type microglia, and ultimately, inhibition of secondary neuronal damage, demonstrating the potential of P. histicola in treating rhinitis - related olfactory dysfunction. This study provides the first evidence that P. histicola ameliorates olfactory bulb damage induced by LPS-induced rhinitis. Our findings offer novel insights into the therapeutic potential of gut microbiota-based interventions for certain neurological disorders.