# Impact of Lactobacillus johnsonii CNCM I-4884 on canine giardiasis: a probiotic-based approach

## TL;DR

This study shows that a probiotic strain, Lactobacillus johnsonii CNCM I-4884, can reduce Giardia infection in dogs, offering a potential alternative to traditional antimicrobials.

## Contribution

The study introduces a novel probiotic-based treatment for canine giardiasis using Lactobacillus johnsonii CNCM I-4884.

## Key findings

- Daily administration of L. johnsonii CNCM I-4884 significantly reduced Giardia cyst shedding in dogs after 14 days.
- The probiotic may act as an adjuvant therapy by supporting intestinal homeostasis and host defense mechanisms.
- The strain could serve as a stand-alone treatment or complement existing antiparasitic therapies.

## Abstract

This study reports a new therapeutic approach for canine giardiasis, the most common intestinal protozoan infection caused by Giardia intestinalis. It is based on the use of the probiotic strain Lactobacillus johnsonii CNCM I-4884 and, in particular, its bile salt hydrolase enzymatic activities. Clinical trials in dogs demonstrated that daily administration of L. johnsonii CNCM I-4884 significantly reduced Giardia cyst shedding after 14 days. These results highlight the potential of this probiotic as a promising alternative to antimicrobials, such as nitroimidazoles or benzimidazoles, for the treatment of giardiasis in dogs. Moreover, they provide a novel approach for the veterinary industry to develop innovative products targeting this parasite. In addition to its direct anti-Giardia effect, L. johnsonii CNCM I-4884 may also act as an adjuvant therapy, supporting intestinal homeostasis, enhancing host defense mechanisms, and promoting recovery of gut balance during or after antiparasitic treatments. This dual role suggests that the strain could be considered not only as a complementary therapy but, in specific cases, as a potential stand-alone probiotic treatment for canine giardiasis.

The online version contains supplementary material available at 10.1186/s13071-025-07166-3.