Why Calories Are Not the Same - a Gut Explanation?

Differences in total fecal energy excretion, determined as total kilocalories excreted via feces, between low and high methane producers following intake of the two controlled, isocaloric diets.

Differences in total fecal energy excretion, determined as total kilocalories excreted via feces, between the two isocaloric diets (that differ in fiber, resistant starch, and particle size).

Differences in fecal energy density, determined as fecal energy (kcal) relative to fecal weight, between high- and low-methane producers.

Differences in total fecal weight excreted, determined as dry weight (grams), between high- and low-methane producers.

Differences in breath methane and hydrogen concentration in exhaled breath, measured in parts per million (PPM), between high- and low-methane producers.

Differences in whole-gut transit time, determined by the passage time of muffins with blue dye, between high- and low-methane producers.

Differences in stool consistency, determined by Bristol Stool Scale, between high- and low-methane producers.

Differences in stool frequency, determined by defecation records registered by the participants, between high- and low-methane producers.

Differences in stool moisture, determined as fecal water content relative to fecal weight, between high- and low-methane producers.

Differences in fecal pH between high- and low-methane producers.

Differences in fecal microbial load, determined as total microbial DNA reads in feces, between high- and low-methane producers.

Differences in fecal host DNA concentration, determined as total human DNA reads in feces, between high- and low-methane producers.

Differences in fecal short-chain fatty acid concentrations between high- and low-methane producers.

Differences in gut microbiome composition, determined by 16S amplicon sequencing of fecal DNA, between high- and low-methane producers.

Differences in gut microbiome taxonomic composition and functions, determined by shotgun sequencing of fecal DNA, between high- and low-methane producers.

Differences in gut microbiome-derived metabolites, such as short-chain fatty acids, bile acids, amino acid-derived metabolites, and other metabolites derived from microbial proteolytic and saccharolytic fermentation measured from fecal samples, between high- and low-methane producers.

Differences in gut microbiome-derived metabolites, such as short-chain fatty acids, bile acids, amino acid-derived metabolites, and other metabolites derived from microbial proteolytic and saccharolytic fermentation measured from urine samples, between high- and low-methane producers.

Differences in gut microbiome-derived metabolites, such as short-chain fatty acids, bile acids, amino acid-derived metabolites, and other metabolites derived from microbial proteolytic and saccharolytic fermentation measured from blood samples, between high- and low-methane producers.

Differences in the fecal metabolome, measured by LC-MS/MS untargeted metabolomics, between high- and low-methane producers.

Differences in the urine metabolome, measured by LC-MS/MS untargeted metabolomics, between high- and low-methane producers.

Differences in the blood metabolome, measured by LC-MS/MS untargeted metabolomics, between high- and low-methane producers.

Differences in the gastrointestinal symptoms during the 3-day intervention period, measured using a visual analog scale, between high- and low-methane producers.

Differences in habitual diet records registered by participants, between high- and low-methane producers.

Differences in habitual physical activity records registered by participants, between high- and low-methane producers.

Differences in body weight before intervention, between high- and low-methane producers.

Differences in body fat composition, measured through Dual-Energy X-ray Absorptiometry (DXA scan), between high- and low-methane producers.

Differences in muscle composition, measured through Dual-Energy X-ray Absorptiometry (DXA scan), between high- and low-methane producers.

Differences in bone composition, measured through Dual-Energy X-ray Absorptiometry (DXA scan), between high- and low-methane producers.

Differences in biomarkers of food intake, measured by untargeted metabolomics and food DNA in fecal samples, between high- and low-methane producers.

Differences in biomarkers of food intake, measured by untargeted metabolomics in urine samples, between high- and low-methane producers.

Differences in biomarkers of food intake, measured by untargeted metabolomics in blood samples, between high- and low-methane producers.

Differences in fecal particle size between high- and low-methane producers.

Differences in fecal carbon-to-nitrogen ratio between high- and low-methane producers.

Differences in fecal redox potential, measured in millivolts (mV), between high- and low-methane producers.

Differences in fecal biomarkers of inflammation, determined by fecal calprotectin, between high- and low-methane producers.

Differences in fecal biomarkers of intestinal permeability, determined by fecal zonulin, between high- and low-methane producers.

Differences in blood markers of glucose metabolism, such as glucose, insulin and HbA1C, between high- and low-methane producers.

Differences in blood markers of lipid metabolism, such as total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides, between high- and low-methane producers.

Differences in blood markers of inflammation, such as CRP, IL-6, TNF-α, and other cytokines, between high- and low-methane producers.

Differences in blood markers of appetite, such as glucagon, GLP-1, GLP-2, PYY, leptin, ghrelin, GIP, and CCK, between high- and low-methane producers.

Differences in blood markers of intestinal permeability, such as lipopolysaccharide-binding protein (LBP), between high- and low-methane producers.