Reduced Neuroinflammation and Pain with a Functional Sourdough Bread Enriched with Legumes and Ancient Cereals in a Mouse Model of LPS-Induced Inflammation

Nutritional strategies based on sourdough fermented breads with wholemeal ancient grains and legumes are emerging as promising modulators of (neuro)immune processes. This study investigated whether prolonged consumption of a sourdough bread enriched with a mixture of ancient cereals and legumes, commercially available in Italy (Primus^® bread, P^®B), modulates neuroimmune systemic responses to repeated lipopolysaccharide (LPS) challenge in mice. For this study, male C57BL/6J mice were fed for 14 days with either a standard diet (SD) or P^®B. Animals then received intraperitoneal LPS (3 mg/kg/day for 3 days) or vehicle. Body weight and food intake were monitored throughout. Pain-like behaviours were assessed by von Frey, plantar and tail flick tests, and plasma cytokine (32-plex panel), splenocyte and peritoneal macrophage cytokine expression, and expression of pro-inflammatory cytokines in sciatic nerves, dorsal root ganglia (DRG) and the spinal cord were analyzed by Reverse Transcription-quantitative Polymerase Chain Reaction (RT-qPCR). P^®B prevented LPS-induced body weight loss and reduced splenomegaly. Unlike SD mice, which exhibited widespread plasmatic cytokine upregulation, P^®B-fed mice displayed only limited increases Interleukin (IL)-1β, IL-12p40 and Tumor Necrosis Factor (TNF)α. Ex vivo cultures of splenocytes and macrophages confirmed attenuated cytokine overexpression. LPS-induced hypersensitivity to mechanical, thermal and nociceptive stimuli was significantly reduced in P^®B mice. Molecular analyses revealed that the P^®B diet blunted the pro-inflammatory cytokine expression present after LPS challenge in the sciatic nerves and DRG, with partial attenuation in the spinal cord. Our findings highlight the great potential of functional foods as affordable dietary strategies to mitigate systemic immune and neuroimmune dysregulation.