Diet-induced extinctions in the gut microbiota compound over generations

Area of Science:

• Microbiology
• Human Biology
• Nutritional Science

Background:

• The gut microbiota plays vital roles in human health, including immune function and metabolism.
• Western populations exhibit reduced gut microbial diversity compared to those with traditional lifestyles.
• Dietary fiber, particularly microbiota-accessible carbohydrates (MACs), is crucial for gut ecosystem health and is reduced in Western diets.

Purpose of the Study:

• To investigate the long-term effects of low microbiota-accessible carbohydrate (MAC) diets on gut microbiota diversity.
• To determine the reversibility of microbiota changes induced by low-MAC diets across generations.
• To identify strategies for restoring gut microbiota diversity.

Main Methods:

• Mice harboring a human microbiota were fed a low-MAC diet.
• Microbiota changes were assessed over several generations.
• Reintroduction of dietary MACs and specific microbial taxa was tested for restoration efficacy.

Main Results:

• Low-MAC diet effects were reversible in the first generation but led to progressive, irreversible diversity loss over subsequent generations.
• Reintroducing dietary MACs alone did not fully restore lost microbial diversity.
• Missing microbial taxa, when administered with MACs, were necessary for microbiota restoration.

Conclusions:

• Prolonged low-MAC diets can lead to generational extinction of crucial gut microbial taxa.
• Microbiota reprogramming for therapeutic purposes may require combining dietary MACs with the reintroduction of specific, missing microbial taxa.
• Strategies targeting the Western microbiota should consider both dietary components and microbial composition.