Rankings / Immune & Inflammation

Lactobacillus acidophilus

Immune & Inflammation · Probiotic strain (lactic acid bacterium)

Tier B

microbiomeotc
6.8 / 10
Tier B
Ev 6 Bn 3.5 Sf 9

Bottom line

Read Off Label grades Lactobacillus acidophilus as B (6.8/10) based on moderate evidence, low-moderate benefit magnitude, and a low-risk safety profile.

Single-strain L.

Typical use: 1-10 billion CFU/day; strain specificity matters — NCFM, La-5, DDS-1 are the better-characterized strains — OTC.

What this is

Single-strain L. acidophilus is the historical 'yogurt' strain. Modern probiotic data is mostly strain-specific — LGG (rhamnosus) and Saccharomyces boulardii outperform acidophilus for AAD/C. difficile. Still reasonable as a baseline daily probiotic. Vaginal health data (often with crispatus or rhamnosus alongside) is the cleanest indication. See also: Probiotics (multi-strain).

Mechanism

Homofermentative Lactobacillus; produces lactic acid and hydrogen peroxide that suppress pathogenic overgrowth; adheres to intestinal epithelium; modulates Th1/Th17/Treg balance; bile-salt-hydrolase activity contributes to modest cholesterol reduction

Dose & route

1-10 billion CFU/day; strain specificity matters — NCFM, La-5, DDS-1 are the better-characterized strains

Citations

Links go to the source. If a link is dead or you want something re-checked, let me know.

Common questions

Does Lactobacillus acidophilus work?
Read Off Label rates the evidence for Lactobacillus acidophilus as Moderate and the benefit magnitude as low-moderate, producing an overall grade of B (6.8/10). Single-strain L.
Is Lactobacillus acidophilus safe?
Lactobacillus acidophilus has a low risk profile in published human data. Legal status: OTC. This is not medical advice — see the disclaimer.
What is the typical dose for Lactobacillus acidophilus?
1-10 billion CFU/day; strain specificity matters — NCFM, La-5, DDS-1 are the better-characterized strains
How does Lactobacillus acidophilus work?
Homofermentative Lactobacillus; produces lactic acid and hydrogen peroxide that suppress pathogenic overgrowth; adheres to intestinal epithelium; modulates Th1/Th17/Treg balance; bile-salt-hydrolase activity contributes to modest cholesterol reduction

This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.