The Neuroprotective Effects of Spray-Dried Porcine Plasma Supplementation Involve the Microbiota-Gut-Brain Axis.

Dietary supplementation with spray-dried porcine plasma (SDP) reduces the Alzheimer's disease (AD) hallmarks in SAMP8 mice. Since gut microbiota can play a critical role in the AD progression, we have studied if the neuroprotective effects of SDP involve the microbiota−gut−brain axis. Experiments were performed on two-month-old SAMP8 mice fed a standard diet and on six-month-old SAMP8 mice fed a control diet or an 8% SDP supplemented diet for four months. Senescence impaired short- and long-term memory, reduced cortical brain-derived neurotrophic factor (BDNF) abundance, increased interleukin (Il)-1ß, Il-6, and Toll-like receptor 2 (Tlr2) expression, and reduced transforming growth factor ß (Tgf-ß) expression and IL-10 concentration (all p < 0.05) and these effects were mitigated by SDP (all p < 0.05). Aging also increased pro-inflammatory cytokines in serum and colon (all p < 0.05). SDP attenuated both colonic and systemic inflammation in aged mice (all p < 0.05). SDP induced the proliferation of health-promoting bacteria, such as Lactobacillus and Pediococcus, while reducing the abundance of inflammation-associated bacteria, such as Johnsonella and Erysipelothrix (both q < 0.1). In conclusion, SDP has mucosal and systemic anti-inflammatory effects as well as neuroprotective properties in senescent mice; these effects are well correlated with SDP promotion of the abundance of probiotic species, which indicates that the gut−brain axis could be involved in the peripheral effects of SDP supplementation.

Dietary Spray-Dried Porcine Plasma Reduces Neuropathological Alzheimer's Disease Hallmarks in SAMP8 Mice.

Alzheimer's disease (AD) is characterized by the aberrant processing of amyloid precursor protein (APP) and the accumulation of hyperphosphorylated tau, both of which are accompanied by neuroinflammation. Dietary supplementation with spray-dried porcine plasma (SDP) has anti-inflammatory effects in inflammation models. We investigated whether dietary supplementation with SDP prevents the neuropathological features of AD. The experiments were performed in 2- and 6-month-old SAMP8 mice fed a control diet, or a diet supplemented with 8% SDP, for 4 months. AD brain molecular markers were determined by Western blot and real-time PCR. Senescent mice showed reduced levels of p-GSK3ß (Ser9) and an increase in p-CDK5, p-tau (Ser396), sAPPß, and the concentration of Aß40, (all p < 0.05). SDP prevented these effects of aging and reduced Bace1 levels (all p < 0.05). Senescence increased the expression of Mme1 and Ide1 and pro-inflammatory cytokines (Il-17 and Il-18; all p < 0.05); these changes were prevented by SDP supplementation. Moreover, SDP increased Tgf-ß expression (p < 0.05). Furthermore, in aged mice, the gene expression levels of the microglial activation markers Trem2, Ym1, and Arg1 were increased, and SDP prevented these increases (all p < 0.05). Thus, dietary SDP might delay AD onset by reducing its hallmarks in senescent mice.

Dietary Supplementation with Spray-Dried Porcine Plasma Attenuates Colon Inflammation in a Genetic Mouse Model of Inflammatory Bowel Disease.

Dietary supplementation with spray-dried porcine plasma (SDP) can modulate the immune response of gut-associated lymphoid tissue. SDP supplementation reduces acute mucosal inflammation, as well as chronic inflammation associated with aging. The aim of this study was to analyze if SDP supplementation could ameliorate colitis in a genetic mouse model of inflammatory bowel disease (IBD). Wild-type mice and Mdr1a knockout (KO) mice were administered a control diet or an SDP-supplemented diet from day 21 (weaning) until day 56. The histopathological index, epithelial barrier, and intestinal immune system were analyzed in the colonic mucosa. KO mice had higher epithelial permeability, increased Muc1 and Muc4 expression, and lower abundance of E-cadherin and Muc2 (all p < 0.001). SDP prevented these effects (all p < 0.05) and decreased the colonic inflammation observed in KO mice, reducing neutrophil and monocyte infiltration and activation and the percentage of activated T helper lymphocytes in the colonic mucosa (all p < 0.05). SDP also diminished proinflammatory cytokine expression and increased the anti-inflammatory IL-10 concentration in the colonic mucosa (all p < 0.05). In conclusion, dietary supplementation with SDP enhances colon barrier function and reduces mucosal inflammation in a mouse model of IBD.