Daily Gut Foundation

Soluble fiber is fermented by gut bacteria into short-chain fatty acids (butyrate, propionate, acetate) that feed colonocytes and modulate the gut microbiome. Psyllium has the strongest evidence for constipation, cholesterol reduction, and glycemic control. Partially hydrolyzed guar gum (PHGG) is gentler on sensitive guts and well-tolerated in IBS. Take with plenty of water.^{[1, 2, 3]}

Probiotics work strain-by-strain, not category-wide. The strongest evidence is for prevention of antibiotic-associated diarrhea (Lactobacillus rhamnosus GG, S. boulardii), shortening of acute infectious diarrhea, and modest improvement in IBS symptoms. Choose products that explicitly name their strains. Refrigerated products generally have better viable CFU counts at expiry.^{[4, 5, 6]}

L-glutamine is the primary fuel source for enterocytes (intestinal epithelial cells). Trial evidence shows benefit for intestinal permeability and IBS symptoms, particularly in post-infectious IBS. Effect sizes are modest and the protocol typically runs 4-8 weeks. Not necessary as a daily forever-supplement for most people.^{[7, 8, 9]}

Saccharomyces boulardii is a non-pathogenic yeast (technically a probiotic, but not a bacterium). The trial evidence is targeted: prevention of antibiotic-associated diarrhea, reduction of Clostridium difficile recurrence, and traveler's diarrhea. Not a daily supplement for everyone — use it for specific situations.^{[10, 11, 12]}