Condition

General Gut Health

Gut health describes how well your digestive tract and its trillions of microbes work together to digest food, support immunity, and keep a barrier against harmful substances. The evidence is strongest for resistant starch, which raised fecal short-chain fatty acids in trials, and for psyllium, which changed stool weight. Those studies were small, with 136 and 32 people, and which way psyllium moved stool weight was unclear.

Sources: PMID 2831263; PMID 465439

Supplements studied: 12
Medicines and peptides: 2
Graded outcomes: 12
Trials: 21
People studied: 1,855

Evidence by supplement

Strong
Moderate
Limited
Very limited

12 supplements

Psyllium

Psyllium: outcomes studied for General Gut Health
Grade	Outcome	Effect	Size	Studies	People
	Fecal Weight Large Increase	Improves (the measure goes down)	Large effect	3 studies	32 people
Studies that measured fecal weight Comparison of the effects of psyllium and wheat bran on gastrointestinal transit time and stool characteristicsJ Am Diet Assoc · PMID 2831263 The effects of a supplement of dietary fibre on faecal excretion by human subjectsBr J Nutr · PMID 465439 An unfermented gel component of psyllium seed husk promotes laxation as a lubricant in humansAm J Clin Nutr · PMID 10966900
	Flatulence	Changes; see studies		1 study	10 people
Studies that measured flatulence Inhibitory actions of a high fibre diet on intestinal gas transit in healthy volunteersGut · PMID 15479674
	Intestinal Motility	Improves (the measure goes up)			12 people
	Lipid Absorption	Improves (the measure goes up)			4 people

Resistant Starch

Resistant Starch: outcomes studied for General Gut Health
Grade	Outcome	Effect	Size	Studies	People
	Fecal Short Chain Fatty Acids Moderate Improvement	Improves (the measure goes up)	Moderate effect		136 people
	Fecal Weight	Improves (the measure goes down)		1 study	138 people
Studies that measured fecal weight Positive effects of resistant starch supplementation on bowel function in healthy adults: a systematic review and meta-analysis of randomized controlled trials.Int J Food Sci Nutr · PMID 27593182

Senna

Constipation Signs and Symptoms: improves
Intestinal Motility: improves

Senna: outcomes studied for General Gut Health
Grade	Outcome	Effect	Size	Studies	People
	Constipation Signs and Symptoms Large Improvement	Improves (the measure goes down)	Large effect	2 studies	8 people
Studies that measured constipation signs and symptoms Efficacy of senna versus lactulose in terminal cancer patients treated with opioidsJ Pain Symptom Manage · PMID 9436336 Safety and efficacy of a bulk laxative containing senna versus lactulose in the treatment of chronic constipation in geriatric patientsPharmacology · PMID 8234438
	Intestinal Motility	Improves (the measure goes up)		8 studies	665 people
Studies that measured intestinal motility Standardized senna in the management of constipation in the puerperium: A clinical trialS Afr Med J · PMID 6996138 The use of senna with docusate for postoperative constipation after pelvic reconstructive surgery: a randomized, double-blind, placebo-controlled trialAm J Obstet Gynecol · PMID 20207340 A volunteer model for the comparison of laxatives in opioid-related constipationJ Pain Symptom Manage · PMID 8935140 and 5 more on the Senna page

Calcium

Fecal Bile Acids: improves
Fecal Cholesterol: changes; see studies
Fecal Water Genotoxicity: changes; see studies

Calcium: outcomes studied for General Gut Health
Grade	Outcome	Effect	Size	Studies	People
	Fecal Bile Acids Small Increase	Improves (the measure goes up)	Small effect	1 study	35 people
Studies that measured fecal bile acids Faecal steroid excretion in humans is affected by calcium supplementation and shows gender-specific differencesEur J Nutr · PMID 19009227
	Fecal Cholesterol	Changes; see studies			35 people
	Fecal Water Genotoxicity	Changes; see studies			35 people

Melatonin

Gastrin: changes; see studies
Plasma Melatonin: improves
Stomach Ulcers: improves

Melatonin: outcomes studied for General Gut Health
Grade	Outcome	Effect	Size	Studies	People
	Gastrin Moderate Increase	Changes; see studies	Moderate effect		30 people
	Plasma Melatonin	Improves (the measure goes up)		1 study	30 people
Studies that measured plasma melatonin Role of melatonin in mucosal gastroprotection against aspirin-induced gastric lesions in humansJ Pineal Res · PMID 20443220
	Stomach Ulcers	Improves (the measure goes up)			30 people

Vitamin E

Serum T4
Triglycerides: improves
Sexual Function: improves

Vitamin E: outcomes studied for General Gut Health
Grade	Outcome	Effect	Size	Studies	People
	Serum T4 No effect		NoneNo effect	1 study	184 people
Studies that measured serum t4 Effects of elevated d-alpha(RRR)-tocopherol dosage in manJ Nutr Sci Vitaminol · PMID 2732807
	Triglycerides	Improves (the measure goes down)		2 studies	184 people
Studies that measured triglycerides Study on the effect of megavitamin E supplementation in manAm J Clin Nutr · PMID 347918 Megavitamin E supplementation in manAm J Clin Nutr · PMID 803000
	Sexual Function	Improves (the measure goes up)			184 people

Tart Cherry Juice

Blood glucose
Uric Acid: improves
Erythrocyte Sedimentation Rate: improves

Tart Cherry Juice: outcomes studied for General Gut Health
Grade	Outcome	Effect	Size	Studies	People
	Blood glucose No effect		NoneNo effect		58 people
	Uric Acid	Improves (the measure goes down)		2 studies	58 people
Studies that measured uric acid Consumption of 100% Tart Cherry Juice Reduces Serum Urate in Overweight and Obese AdultsCurr Dev Nutr · PMID 31037275 Thirty Days of Montmorency Tart Cherry Supplementation Has No Effect on Gut Microbiome Composition, Inflammation, or Glycemic Control in Healthy AdultsFront Nutr · PMID 34604282
	Erythrocyte Sedimentation Rate	Improves (the measure goes down)			58 people
	Insulin	Changes; see studies			58 people
	Microbiome	Improves (the measure goes up)			58 people
	TNF-Alpha	Improves (the measure goes down)			58 people

Colostrum

Body Temperature
Weight: improves
Oxygen Uptake: improves

Colostrum: outcomes studied for General Gut Health
Grade	Outcome	Effect	Size	Studies	People
	Body Temperature No effect		NoneNo effect		12 people
	Weight	Improves (the measure goes down)		5 studies	30 people
Studies that measured weight The effects of bovine colostrum supplementation on body composition and exercise performance in active men and womenNutrition · PMID 11312068 Effect of bovine colostrum supplementation on the composition of resistance trained and untrained limbs in healthy young menEur J Appl Physiol · PMID 14504943 Effect of bovine colostrum on anaerobic exercise performance and plasma insulin-like growth factor IJ Sports Sci · PMID 12848392 and 2 more on the Colostrum page
	Oxygen Uptake	Improves (the measure goes up)		2 studies	42 people
Studies that measured oxygen uptake The nutriceutical bovine colostrum truncates the increase in gut permeability caused by heavy exercise in athletesAm J Physiol Gastrointest Liver Physiol · PMID 21148400 Bovine colostrum supplementation during running training increases intestinal permeabilityNutrients · PMID 22253980
	Intestinal Permeability	Improves (the measure goes up)		1 study	42 people
Studies that measured intestinal permeability Co-administration of the health food supplement, bovine colostrum, reduces the acute non-steroidal anti-inflammatory drug-induced increase in intestinal permeabilityClin Sci · PMID 11352778
	Fat Oxidation	Improves (the measure goes up)			12 people
	Ghrelin	Improves (the measure goes up)			12 people
	Glucagon-like peptide 1 (GLP-1)	Improves (the measure goes up)			12 people

Cocoa Extract

Triglycerides: improves

Cocoa Extract: outcomes studied for General Gut Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Triglycerides	Improves (the measure goes down)		3 studies	22 people
Studies that measured triglycerides Prebiotic evaluation of cocoa-derived flavanols in healthy humans by using a randomized, controlled, double-blind, crossover intervention studyAm J Clin Nutr · PMID 21068351 Acute effect of oral flavonoid-rich dark chocolate intake on coronary circulation, as compared with non-flavonoid white chocolate, by transthoracic Doppler echocardiography in healthy adultsInt J Cardiol · PMID 18045712 Dark chocolate consumption improves leukocyte adhesion factors and vascular function in overweight menFASEB J · PMID 24302679

Inulin

Bifidobacterium Abundance: improves

Inulin: outcomes studied for General Gut Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Bifidobacterium Abundance	Improves (the measure goes up)		1 study	388 people
Studies that measured bifidobacterium abundance Effect of Fructooligosaccharides Supplementation on the Gut Microbiota in Human: A Systematic Review and Meta-Analysis.Nutrients · PMID 36014803

Peppermint

Gastric Emptying Rate: changes; see studies

Peppermint: outcomes studied for General Gut Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Gastric Emptying Rate	Changes; see studies		1 study	10 people
Studies that measured gastric emptying rate Early effects of peppermint oil on gastric emptying: a crossover study using a continuous real-time 13C breath test (BreathID system)J Gastroenterol · PMID 17653649

Lactobacillus reuteri

Immunoglobulin A: improves

Lactobacillus reuteri: outcomes studied for General Gut Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Immunoglobulin A	Improves (the measure goes up)		1 study	23 people
Studies that measured immunoglobulin a Salivary IgA response to probiotic bacteria and mutans streptococci after the use of chewing gum containing Lactobacillus reuteriPathog Dis · PMID 23737255

Prescription medicines and peptides studied, for context

These are not supplements. Most need a prescription, and some are research compounds with no approved use. They are listed so the supplement evidence above can be read against them.

2 medicines and peptides

KPV

Colitis Severity (Animal): improves
Intestinal Inflammation (Animal): improves

KPV: outcomes studied for General Gut Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Colitis Severity (Animal) Significant reduction in inflammatory infiltrates and MPO activity in DSS and TNBS colitis models	Improves (the measure goes down)	Large effect	69 studies	120 people
	Intestinal Inflammation (Animal) Rescued all animals from death in MC1R-deficient mice during DSS colitis	Improves (the measure goes down)	Large effect	68 studies	150 people

BPC-157

Gastric Ulcer Healing: improves
Intestinal Inflammation: improves

BPC-157: outcomes studied for General Gut Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Gastric Ulcer Healing Notable Improvement (mostly animal data)	Improves (the measure goes up)	Large effect	12 studies	240 people
	Intestinal Inflammation Moderate Decrease (mostly animal data)	Improves (the measure goes down)	Moderate effect	6 studies	150 people

Key findings

Fecal WeightPsylliumImproves (the measure goes down)
Fecal Short Chain Fatty AcidsResistant StarchImproves (the measure goes up)
Constipation Signs and SymptomsSennaImproves (the measure goes down)

The General Gut Health (Digestive Wellness) protocol

2 primary supplements · 5 supporting supplements

Psyllium Husk5–10 g daily with plenty of water
Resistant Starch15–30 g daily (green banana flour, raw potato starch, or cooked-cooled starch)

See the full protocol

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Studies cited

6 studies from PubMed

A low FODMAP diet is associated with changes in the microbiota and reduction in breath hydrogen but not colonic volume in healthy subjectsPLoS One · PMID 30048547
Diets that differ in their FODMAP content alter the colonic luminal microenvironmentGut · PMID 25016597
Effect of a short-term low fermentable oligiosaccharide, disaccharide, monosaccharide and polyol (FODMAP) diet on exercise-related gastrointestinal symptomsJ Int Soc Sports Nutr · PMID 30646926
Effect of administering kefir on the changes in fecal microbiota and symptoms of inflammatory bowel disease: A randomized controlled trialTurk J Gastroenterol · PMID 30662004
Effect of special Hungarian probiotic kefir on faecal microfloraWorld J Gastroenterol · PMID 16534858
No effects of a 4-week post-exercise sauna bathing on targeted gut microbiota and intestinal barrier function, and hsCRP in healthy men: a pilot randomized controlled trial.BMC Sports Sci Med Rehabil · PMID 35710395