# The impact of probiotic administration on experimental in vitro and in vivo infection by Trypanosoma cruzi

## TL;DR

This study explores how probiotics affect Trypanosoma cruzi infection in mice and cells, showing some reduction in parasite levels but no protection against death.

## Contribution

The study demonstrates that specific probiotics can reduce T. cruzi infection in vitro and in vivo when used alone or with benznidazole.

## Key findings

- LR and PB8 probiotics reduced parasitaemia in mice by 44-87% and 23-16%, respectively.
- PB8 increased benznidazole's effectiveness by 40% in reducing parasitism in macrophages.
- Probiotics showed no protective effect against mortality in infected mice.

## Abstract

Chagas disease (CD) caused by Trypanosoma cruzi has limited therapy. Probiotics sustain healthy microbiota, playing roles in biological events.

Our aim was to determine the impact of probiotics on T. cruzi infection in vitro and in mouse acute experimental models.

The multi strain - PB8 and the Lactobacillus rhamnosus (LR) were orally administered [106-109 colony-forming units (CFU)] for seven days prior to mice infection followed for 14 daily administrations. Peritoneal mouse macrophages (PMM) were obtained from mice treated with 109 probiotics one day before collection and infected in vitro with or not benznidazole (BZ).

LR and PB8 reduced by 44-87% and 23-16% the parasitaemia peak in male and female mice, respectively, but did not protect against mortality. Histopathology showed mild reduction in cardiac nests due to probiotics’ administration. PB8 and LR suppressed the parasite infection of PMM by 24 and 26%, reaching 65 and 42% of declines, respectively when 3% thioglycolate was performed. PB8 increased BZ activity at 1 µM, reaching 40% of parasitism’ declines compared to BZ alone (25%). No gender difference was noticed during probiotic in vivo administration.

The results point to the potential of a combined therapeutic approach for CD, using probiotics and BZ.