Innovative Probiotic Strain Shows Enhanced Efficacy Against Common Intestinal Infection

Recent research has unveiled a novel probiotic strain, Lactobacillus johnsonii CNCM I-4884, demonstrating significant effectiveness in combating giardiasis, a prevalent intestinal infection caused by the protozoan Giardia intestinalis. This infection is not only the foremost cause of intestinal parasitic diseases in humans but also affects pets, particularly dogs. Symptoms include diarrhea, abdominal discomfort, nausea, and weight loss, with potential long-term complications such as irritable bowel syndrome (IBS) and chronic fatigue.

As resistance to traditional treatment options, such as nitroimidazoles, becomes increasingly common, researchers have turned their focus to this promising probiotic strain. Patented by INRAE, MNHN, and EnvA in 2015, L. johnsonii has shown substantial anti-Giardia activity, hindering the parasite's growth within the intestinal tract. The objective is to develop a more resilient bacterial strain that can withstand digestive processes, display enhanced effectiveness against the parasite, and be suitable for industrial-scale production.

The study, published in the journal Gut Microbes, outlines the advancements made with L. johnsonii. This bacterium, which is naturally found in the gut microbiota, can convert conjugated bile salts--critical for Giardia's growth--into unconjugated bile salts, which are toxic to the parasite. This transformation is vital not only for digestion but also plays an anti-inflammatory role in the intestine.

To enhance the strain's resistance to bile salts, the research team subjected L. johnsonii CNCM I-4884 to increasing concentrations of bile salts in a laboratory setting. Through this screening process, they identified a derivative strain exhibiting superior bile salt transformation capabilities and prolonged viability during culture.

The effectiveness of the selected strain was tested in a murine model infected with G. intestinalis. Results revealed that the derivative strain achieved a remarkable 64.4% reduction in parasite load compared to the 48.8% reduction observed with the wild-type strain. Consequently, this newly developed strain is 15% more effective against giardiasis.

Currently, a probiotic medication based on L. johnsonii is in the final phases of clinical trials and is expected to be available for canine treatment shortly. The implications of this study pave the way for developing probiotic therapies to address giardiasis in both animals and humans in the near future.

For further insights, refer to the publication: Isolation of derivatives from the food-grade probiotic Lactobacillus johnsonii CNCM I-4884 with enhanced anti-Giardia activity, Gut Microbes, DOI: 10.1080/19490976.2025.2474149.