Bacillus subtilis (spore probiotic)

Tier 2 — promising · Probiotic · Gut · Immune

A spore-forming soil probiotic with excellent gastric survival (spores resist stomach acid and heat) and a distinct mechanism from lactobacilli. B. subtilis DE111, HU58, and R0179 strains have RCT evidence for improved bowel regularity, reduced bloating, and immune modulation. Spore probiotics transiently colonise — they don't establish permanent residency but produce bioactive metabolites (bacteriocins, nattokinase-like enzymes) and crowd out pathogens during transit. Generally well-tolerated; rare bacteraemia concerns in severely immunocompromised patients.

Dose: 1–5 billion CFU (spore-based) daily