Gut Microbiome and Metabolome Variations in Self-Identified Muscle Builders Who Report Using Protein Supplements

Area of Science:

• Microbiology
• Nutritional Science
• Metabolomics

Background:

• Muscle builders often use protein supplements, but their impact on gut microbiota is poorly understood.
• Dietary protein intake is a key factor influencing gut microbiome composition and function.

Purpose of the Study:

• To compare the gut microbiome and metabolome of muscle builders with and without protein supplement consumption.
• To investigate the effects of high protein intake on gut microbial metabolism and nitrogen processing.

Main Methods:

• Fecal samples were collected from participants (protein supplement (PS) group vs. No PS group).
• Gut microbiome was analyzed using 16S rRNA gene sequencing.
• Fecal metabolome was analyzed using untargeted metabolomics.
• Dietary intake was assessed via 24-h food recalls (ASA24).

Main Results:

• The PS group consumed significantly more protein (169 ± 18 g) than the No PS group (118 ± 12 g).
• Distinct metabolic profiles were observed, with higher allantoin levels in the PS group.
• The bacteria order Lactobacillales was significantly higher in the PS group (p = 0.007).
• Bacterial genes related to nucleotide metabolism were more highly expressed in the No PS group (p < 0.001).

Conclusions:

• Higher protein intake from supplements impacts nitrogen metabolism in muscle builders.
• Protein supplement consumption alters gut microbiome composition, favoring bacteria involved in purine metabolism.
• Changes in gut microbial nucleotide metabolism pathways are associated with high protein intake.