Intermittent Fasting Tops Calorie Restriction for Gut Health

TOPLINE:

Individuals on an intermittent-fasting and protein-pacing (IF-P) diet had fewer gastrointestinal symptoms and increased diversity in gut microbiota than those on a calorie-restricted (CR) Mediterranean-style diet in a small, randomized trial.

METHODOLOGY:

• Researchers compared the effects on gastrointestinal symptoms, the gut microbiome, and circulating cytokines and metabolites of two low-calorie, 8-week dietary interventions: A Mediterranean-style continuous CR diet based on US dietary recommendations and an IF-P diet. The interventions were matched for energy intake.
• Participants included men and women with overweight/obesity who were randomly assigned to one of the two groups: CR diet (n = 20) and IF-P diet (n = 21).
• Researchers used samples and data from an ongoing randomized controlled trial comparing the effects of the CR diet vs the IF-P diet on anthropometric and cardiometabolic outcomes.
• In a subanalysis for the current study, researchers compared outcomes in “high” and “low” responders to the IF-P regimen, based on relative weight loss.

TAKEAWAY:

• The IF-P diet resulted in more substantial reductions in patient-reported symptoms of gastrointestinal problems and more pronounced increases in gut microbiota diversity and in the abundance of microbial families and genera associated with favorable metabolic profiles, such as Christensenellaceae, Rikenellaceae, and Marvinbryantia, than the CR diet.
• The IF-P diet significantly increased cytokines linked to lipolysis, weight loss, inflammation, and the immune response.
• With the CR diet, metabolites associated with a longevity-related metabolic pathway increased.
• The subgroup analysis of high and low responders to the IF-P diet showed an increased abundance of certain bacteria associated with metabolic benefits and anti-inflammatory effects among high responders, whereas low responders showed an increased abundance of butyrate-producing and nutritionally adaptive species such as Eubacterium ventriosum and Roseburia inulinivorans.
• A fecal metabolome analysis revealed that high responders showed enrichment of fecal metabolites involved in lipid metabolism, whereas more prominent pathways in low responders were related to the metabolism of amino acids and peptides, as well as tyrosine metabolism and arginine biosynthesis.

IN PRACTICE:

“These findings shed light on the differential effects of IF regimens, including IF-P, as a promising dietary intervention for obesity management and microbiotic and metabolic health.”

SOURCE:

The study, with corresponding author Paul J. Arciero, PhD, of the Human Nutrition and Metabolism Laboratory at Skidmore College, Saratoga Springs, New York, was published online in Nature Communications.

LIMITATIONS:

The reliance on fecal samples to represent the gut microbiome may have overlooked potential microbial populations in the upper gastrointestinal tract. Other limitations include the short, 8-week duration of the trial and small number of patients.

DISCLOSURES:

The study was primarily funded by an unrestricted grant from Isagenix International LLC to Arciero, with secondary funding provided to a coauthor. Arciero is a consultant for Isagenix International LLC, is an advisory board member of the International Protein Board, and received financial compensation for books and keynote presentations on protein pacing.