In a recent study published in the journal Nature Communications, researchers compare the effects of intermittent fasting with protein pacing (IF-P) with heart-healthy calorie restriction (CR) on gut microbiota remodeling and metabolomic profiles.
Nutrition and the Microbiome: Key Insights
The gut microbiome plays a crucial role in weight management and gastrointestinal health. Nutritional choices can influence both gut bacteria and body weight, offering potential treatments for metabolic disorders.
Study Overview
A study conducted in Saratoga Springs, New York, involved overweight or obese adults aged 30 to 65. Participants were either inactive or minimally active and were randomly assigned to follow either an intermittent fasting with protein pacing (IF-P) or calorie restriction (CR) diet for eight weeks. The study included 21 individuals in the IF-P group and 20 in the CR group.
Participants’ calorie intake and expenditure were matched. Those using antibiotics, antifungals, or probiotics in the past two months were excluded. The study assessed changes in food intake, body weight, cardiometabolic outcomes, hunger ratings, and gut flora. Participants completed the gastrointestinal symptom rating scale (GSRS) at the start and at weeks four and eight.
Methodology
Researchers collected fecal samples for DNA extraction and qPCR analysis to determine bacterial biomass and composition. Blood samples were taken for body composition evaluations and biochemical analysis, including serum metabolomic analysis using liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-MS for short-chain fatty acid (SCFA) analysis.
16S rRNA sequencing and linear-mixed effects modeling were used to study the impact of IF-P on gut bacteria and stool parameters. Multi-omics factor analysis identified patterns between the microbiome and circulating metabolites.
IF-P involved four meals per day, each containing 25-50 grams of protein, with a diet comprising 35% carbohydrates, 30% fat, and 35% protein for five to six days each week. The CR diet included 41% carbohydrates, 38% fat, and 21% protein, aligning with U.S. dietary guidelines. Participants received supplements and snacks on IF days, while protein pacing days involved four to five meals daily.
Study Findings
IF-P significantly influenced gastrointestinal symptoms, gut microbial diversity, and circulating metabolites more than CR. It increased counts of Marvinbryantia, Christensenellaceae, and Rikenellaceae and raised levels of cytokines and amino acid metabolites promoting fatty acid oxidation.
IF-P enhanced cytokines involved in lipolysis, inflammation, weight loss, and immune response, such as interleukin-4 (IL-4), IL-6, IL-8, and IL-13. In contrast, CR increased metabolites linked to longevity.
Gut microbiota and metabolomic factors affected weight loss maintenance and body composition. IF-P had a more significant impact on gut microbiota dynamics than CR. Participants on IF-P reduced their total fat, carbohydrate, salt, sugar, and calorie intake by 40% and increased protein consumption more than those on CR. The IF-P group lost more body weight, total fat, abdominal fat, and visceral fat, with a 33% reduction in visceral fat.
Conclusions
IF-P improved gastrointestinal symptoms and increased levels of Christensenella, a gut bacterium linked to a lean phenotype. It also raised circulating cytokines that regulate body weight and fat reduction. The findings highlight the importance of personalized dietary approaches for optimal weight control and metabolic health.
Further research is needed to understand the mechanisms behind these observations and to develop personalized obesity control strategies. These results may guide future gut microbiome-focused dietary recommendations with larger sample sizes and longer study durations.
