Cognitive impairment and CSF proteome modification after oral bacteriotherapy in HIV patients

Objective: To investigate whether a probiotic supplementation to cART patients modifies the cerebrospinal fluid (CSF) proteome and improves neurocognitive impairment. Methods: 26 CSF samples from 13 HIV-positive patients [six patients living with HIV (PLHIV) and seven patients with a history of AIDS (PHAIDS)] were analyzed. All patients underwent to neurocognitive evaluation and blood sampling at baseline and after 6 months of oral bacteriotherapy. Immune phenotyping and activation markers (CD38 and HLA-DR) were evaluated on peripheral blood mononuclear cells (PBMC). Plasma levels of IL-6, sCD14, and MIP-1 beta were detected, by enzyme-linked immunosorbent assay (ELISA). Functional proteomic analysis of CSF sample was conducted by two-dimensional electrophoresis; a multivariate analysis was performed by principal component analysis (PCA) and data were enriched by STRING software. Results: Oral bacteriotherapy leads to an improvement on several cognitive test and neurocognitive performance in both groups of HIV-positive subjects. A reduction in the percentage of CD4(+)CD38(+)HLA-DR+ T cells was also observed at peripheral level after the probiotic intake (p = 0.008). In addition, the probiotic supplementation to cART significantly modifies protein species composition and abundance at the CSF level, especially those related to inflammation (beta 2-microglobulin p = 0.03; haptoglobin p = 0.06; albumin p = 0.003; hemoglobin p = 0.003; immunoglobulin heavy chains constant region p = 0.02, transthyretin p = 0.02) in PLHIV and PHAIDS. Conclusions: Our results suggest that oral bacteriotherapy as a supplement to cART could exert a role in the amelioration of inflammation state at peripheral and CNS level.