Microbiota-produced indole metabolites disrupt mitochondrial function and inhibit Cryptosporidium parvum growth

Area of Science:

• Microbiology
• Parasitology
• Metabolomics

Background:

• Cryptosporidiosis is a significant cause of severe diarrhea in young children, particularly in resource-limited areas.
• Understanding the role of gut microbiota in susceptibility to Cryptosporidium infection is crucial for developing effective interventions.

Purpose of the Study:

• To investigate the impact of microbiota-associated metabolites on the growth of Cryptosporidium parvum.
• To identify specific metabolites that can inhibit parasite growth and reduce infection severity.

Main Methods:

• Screening of 85 microbiota-associated metabolites for their in vitro effects on Cryptosporidium parvum.
• Assessing the mechanism of action of inhibitory metabolites, including effects on host and parasite mitochondrial function.
• Evaluating the in vivo efficacy of indole administration and gut microbiota reconstitution in a mouse model of Cryptosporidium infection.

Main Results:

• Eight metabolites, including secondary bile salts/acids, a vitamin B6 precursor, and indoles, demonstrated inhibitory effects on C. parvum growth.
• Indoles were found to impair host mitochondrial function, reduce cellular ATP, and disrupt the parasite's mitosome membrane potential.
• Oral indole administration and reconstitution with indole-producing bacteria in mice reduced parasite life cycle progression and infection severity.

Conclusions:

• Microbiota metabolites, particularly indoles, can inhibit Cryptosporidium parvum growth by targeting mitochondrial function.
• These findings highlight the potential of manipulating gut microbiota metabolites for therapeutic strategies against cryptosporidiosis.
• Microbial metabolites contribute to colonization resistance against Cryptosporidium infection, offering insights into host-parasite interactions.