The Efficacy of Fecal Transplantation and Bifidobacterium Supplementation in Ameliorating Propionic Acid-Induced Behavioral and Biochemical Autistic Features in Juvenile Male Rats.

Gut microbiota plays a major role in neurological disorders, including autism. Modulation of the gut microbiota through fecal microbiota transplantation (FMT) or probiotic administration, such as Bifidobacteria, is suggested to alleviate autistic symptoms; however, their effects on the brain are not fully examined. We tested both approaches in a propionic acid (PPA) rodent model of autism as treatment strategies. Autism was induced in Sprague-Dawley rats by administering PPA orally (250 mg/kg) for 3 days. Animals were later treated with either saline, FMT, or Bifidobacteria for 22 days. Control animals were treated with saline throughout the study. Social behavior and selected brain biochemical markers related to stress hormones, inflammation, and oxidative stress were assessed. PPA treatment induced social impairments, which was rescued by the treatments. In the brain, Bifidobacteria treatment increased oxytocin relative to control and PPA groups. Moreover, Bifidobacteria treatment rescued the PPA-induced increase in IFN-γ levels. Both treatments increased GST levels, which was diminished by the PPA treatment. These findings indicate the potential of gut microbiota-targeted therapeutics in ameliorating behavioral deficit and underlying neural biochemistry.

Bee pollen and propolis improve neuroinflammation and dysbiosis induced by propionic acid, a short chain fatty acid in a rodent model of autism.

BACKGROUND: Neuroinflammation plays a major role in the pathogenesis of autism because the cytokine levels are typically disturbed in the brain in autistic patients. Prebiotics-rich diet maintains the healthy gut microbiota and hence can regulate the neuroinflammation indirectly. The study aimed to investigate the role of bee pollen and propolis in ameliorating neuroinflammation, including cytokine levels, in an animal model of autism. METHODS: Hamsters were classified as four groups: Group I, control; Group II, autistic model/animals treated with 250 mg propionic acid (PPA)/kg body weight (BW)/day for 3 days; Group III, animals treated with bee pollen at a dose of 250 mg/kg BW/day for 4 weeks; and Group IV, animals treated with propolis at a dose of 250 mg/kg BW/day for 4 weeks. Neuroinflammatory responses were evaluated using the levels of interferon γ (IFN-γ), interleukin 1 alpha (IL-1α), IL-6, IL-10, IL-12 (p70), vascular endothelial growth factor (VEGF), and tumor necrosis factor α (TNFα). RESULTS: Significant decrease of IL-10 (P<0.026), VEGF (P<0.005), and TNFα(P<0.005) levels and increased IL-1α (P<0.032), IL-6(P<0.028), and IFN-γ (P<0.013) levels were observed between the four studied groups. The neurotoxic effects of PPA was clearly presented as much higher IL-6, as pro-inflammatory cytokine (P<0.05), concomitant with much lower IL-10, as anti-inflammatory cytokine(P<0.015) compared to controls. Both bee pollen and propolis were effective in ameliorating the neurotoxic effects of PPA demonstrating non-significant changes of IL-6 and IL-10 when compared to control healthy hamsters. CONCLUSIONS: Our findings indicate that both bee pollen and propolis protect against neuroinflammation in the rodent model of autism. However, further studies are needed to investigate the clinical benefits of prebiotics-rich diet in neurodevelopmental disorders, such as autism.

The Independent and Combined Effects of Omega-3 and Vitamin B12 in Ameliorating Propionic Acid Induced Biochemical Features in Juvenile Rats as Rodent Model of Autism.

Metabolites of proper fatty acids modulate the inflammatory response and are essential for normal brain development; equally, abnormal fatty acid metabolism plays a critical role in the pathology of autism. Currently, dietary supplements are often used to improve the core symptoms of Autism spectrum disorder (ASD). The present study analyzed the effects of orally supplemented omega-3 (ω-3) and vitamin B12 on ameliorating oxidative stress and impaired lipid metabolism in a propionic acid (PPA)-induced rodent model of autism, together with their effect on the gut microbial composition, where great fluctuations in the bacterial number and strains were observed; interestingly, polyunsaturated fatty acids such as omega-3 induced higher growth of the gram-positive bacterium Staphylococcus aureus and decreased the survival rates of Clostridia sp. as well as other enteric bacterial strains. Thirty-five young male western albino rats were divided into five equal groups. The first group served as the control; the second group was given an oral neurotoxic dose of PPA (250 mg/kg body weight/day) for 3 days. The third group received an oral dose of ω-3 (200 mg/kg body weight/day) for 30 days after the 3-day PPA treatment. Group four was given an oral dose of vitamin B12 (16.7 mg/kg/day) for 30 days after PPA treatment. Finally, group five was given a combination of both ω-3 and vitamin B12 at the same dose for the same duration after PPA treatment. Biochemical parameters related to oxidative stress and impaired fatty acid metabolism were investigated in the brain homogenates of each group. The effects of the dietary supplements on the gut microbiota were also observed. The PPA-treated autistic model expressed significantly higher levels of lipid peroxides and 5-lipoxygenase (5-LOX) and significantly less glutathione (GSH), glutathione S-transferase (GST), and cyclooxygenase 2 (COX2) than the control group. However, a remarkable amelioration of most of the impaired markers was observed with oral supplementation with ω-3 and vitamin B12, either alone or in combination. Our results concluded that impairment at various steps of the lipid metabolic pathways may contribute to the development of autism; however, supplementation with ω-3 and vitamin B12 can result in a positive therapeutic effect.