Lactobacillus acidophilus NCFM
A heavily characterized acidophilus strain with its best human data in pediatric immune support and combination-formula bloating relief.
Evidence tier
Mixed
Research weight
Citations
10 verified / 10
Classification
Probiotics
❝
What the evidence says. Conflicting results across studies; benefit uncertain.
What is Lactobacillus acidophilus NCFM?
Lactobacillus acidophilus NCFM is a probiotic strain used for reduces incidence and duration of cold/flu-like symptoms (fever, cough, runny nose) in young children, especially combined with b. lactis bi-07. NutriDex grades the human evidence as Mixed. Lactobacillus acidophilus NCFM is one of the most studied probiotic strains, but its clinical evidence is genre-specific and uneven. The strongest signal is from a 6-month pediatric RCT where NCFM (alone, and especially combined with B. lactis Bi-07) significantly cut the incidence and duration of fever, cough, and rhinorrhea and reduced antibiotic use in 3-5 year olds. For gut symptoms, an NCFM + Bi-07 combination reduced bloating severity in functional bowel disorders, but a large 340-patient triple-blind trial of NCFM alone for IBS found symptom improvement no better than placebo. NCFM also has lactase activity that can ease lactose digestion. Overall, benefit is real for specific formulations/indications but not a blanket "IBS cure."
Purported Benefits
✓Reduces incidence and duration of cold/flu-like symptoms (fever, cough, runny nose) in young children, especially combined with B. lactis Bi-07
✓Lowers antibiotic prescriptions and illness-related missed school days in preschoolers (immune support)
✓Reduces bloating severity in functional bowel disorders when combined with B. lactis Bi-07
✓Helps digest lactose / eases lactose-intolerance symptoms via its high lactase activity
✓Upregulates colonic mu-opioid receptor expression, a plausible mechanism for visceral analgesia in functional abdominal pain
✓Generally well tolerated and confirmed to survive GI transit
Evidence by outcome
The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.
| Outcome | Evidence | Effect | Studies |
|---|---|---|---|
| Reduces cold/flu-like symptoms in young children (esp. with B. lactis Bi-07)One 6-month pediatric RCT (n=326); strongest as the NCFM+Bi-07 combination, not NCFM alone. | Preliminary | ↑ benefit · moderate | 1 |
| Lowers antibiotic use / missed school days in preschoolersSecondary outcomes of the single Leyer 2009 RCT; not independently replicated for this strain. | Preliminary | ↑ benefit · moderate | 1 |
| Reduces bloating in functional bowel disorders (with B. lactis Bi-07)One 8-week RCT (n=60) of the combination; NCFM-alone effect not isolated. | Preliminary | ↑ benefit · small | 1 |
| Improves IBS symptom severity (NCFM alone)Large triple-blind RCT (n=340) found NCFM alone no better than placebo on IBS-SSS. | Moderate | — no effect · negligible | 1 |
| Upregulates colonic mu-opioid receptor (visceral analgesia mechanism)Single small RCT (n=20) mechanistic finding; not a clinical pain endpoint. | Preliminary | ↑ benefit | 1 |
Dosing & Compounds
Typical Dose
Trials used roughly 1 x 10^9 to 1 x 10^10 CFU/day for adult gut studies; the pediatric immune trial gave ~1 x 10^10 CFU twice daily for 6 months; the functional bowel/bloating combination trial used 2 x 10^11 CFU/day (1 x 10^11 BID) of NCFM + Bi-07. Taken orally, typically once or twice daily with no strict timing requirement.
Active Compounds
Safety & Cautions
Excellent tolerability across adult and pediatric RCTs with no clinically significant increase in adverse events; mild transient bloating/gas can occur. The strain (and HOWARU Restore blend) carries FDA GRAS and EU QPS-equivalent safety status, lacks transferable antibiotic-resistance and harmful genomic traits. As with all live Lactobacillus probiotics, use caution in critically ill, immunocompromised, or central-venous-catheter patients given rare reports of bacteremia in such populations; not a substitute for standard medical therapy. Educational only — always check with your doctor or pharmacist before combining Lactobacillus acidophilus NCFM with any medicine.
Key Studies ★ 10 studies
Cochrane review
Cochrane plain-language summary 2022
✓ Full text
Full-text Cochrane review reporting on roughly 4,364 participants (2,320 probiotic, 2,044 control) across RCTs, concluding probiotics may be better than placebo for preventing at least one and at least three acute upper respiratory tract infections.
Systematic review
Wang 2016
✓ Full text
Systematic review and meta-analysis of RCTs found probiotics reduced the number of children with respiratory tract infection episodes and lowered antibiotic use compared with placebo.
RCT
Cassís-Nosthas 2026
✓ PubMed
Quantification of Changes in Bifidobacteria and Lactobacilli Colony-forming Units During Rifaximin Treatment and Synbiotic Gel in Healthy Volunteers
RCT
Ringel-Kulka 2017
✓ Full text
Triple-blind RCT in 340 IBS adults: NCFM alone at 10^9 or 10^10 CFU/day for 12 weeks improved IBS-SSS no more than placebo (mean drop 50.8 / 48.3 vs 44.0 placebo), i.e., no benefit over placebo for symptom severity.
RCT
Ringel-Kulka 2011
✓ PubMed
8-week double-blind RCT (n=60, functional bowel disorders): NCFM + B. lactis Bi-07 at 2x10^11 CFU/day improved abdominal bloating vs placebo at 4 weeks (4.10 vs 6.17, P=0.009) and reduced bloating severity at 8 weeks (P<0.01).
RCT
Ringel 2014
✓ Full text
Randomized clinical study (n=20 women, functional abdominal pain): NCFM alone induced ~40-fold increase in colonic mucosal mu-opioid receptor (MOR) mRNA/protein and downstream STAT3 signalling; the NCFM+Bi-07 combination did not.
RCT
Andreasen 2010
✓ PubMed
Randomized, double-blind, placebo-controlled trial (n=45): 4 weeks of NCFM did not significantly alter insulin sensitivity overall, though it preserved insulin sensitivity in a subgroup and attenuated systemic inflammatory response.
RCT
Leyer 2009
✓ PubMed
6-month RCT in 326 children (3-5 yr): vs placebo, NCFM and NCFM+Bi-07 reduced fever incidence by 53.0% and 72.7%, cough by 41.4% and 62.1%, and rhinorrhea by 28% and 59%, with fewer antibiotic prescriptions and missed school days.
safety evaluation
Morovic 2017
✓ PubMed
Safety evaluation of HOWARU Restore (NCFM + Lpc-37 + Bl-04 + Bi-07): no transferable antibiotic-resistance determinants, no virulence genomic risk factors, and no acute oral toxicity.
review
Senok / Sanders review 2001
✓ PubMed
Invited review synthesizing NCFM's probiotic functionality: documents high intrinsic lactase activity, acid/bile tolerance, and human GI survival supporting lactose digestion and colonization claims.