Benefits
Immune defense during winter training in elite athletes
In 39 elite athletes given 20 billion CFU a day or placebo for 14 winter weeks, cold-like symptom episodes lasted about 7 days versus 11 on placebo (p = 0.047), and fewer symptoms were reported. How often episodes occurred and how severe they were did not differ, and the published summary named no single main outcome. The trial was small and has not been repeated.
Antibody levels in blood and saliva of athletes
In 30 athletes over 14 weeks, total IgA in serum and saliva fell on placebo but not on the probiotic, and some IgA and IgG antibodies to specific bacteria were higher than on placebo. Total IgM rose in both groups. These are lab markers, not proof of fewer illnesses.
Oxidative stress markers in endurance athletes
In 22 male endurance athletes over 14 weeks, two blood markers of oxidative damage, malondialdehyde and oxidized proteins, fell on the probiotic and not on placebo. Total antioxidant status and most other measures did not change. These are blood markers, not a performance or health outcome.
Endurance capacity in recreational runners
In 28 recreational runners, 5 billion CFU a day for 6 weeks did not improve time to exhaustion on a treadmill. Time rose on placebo and not on the probiotic, and the probiotic group trained less often and less hard during the study. Stomach and cold symptoms were few in both groups.
Infant immune development and allergen sensitization
Newborns of allergic mothers took 3 billion CFU a day or placebo for 6 months. Skin allergy rates did not differ at 6 or 12 months or at 2.5 years, and skin test sensitization at 1 year was more common on the probiotic. Fewer stomach infections were reported in the probiotic group at the 2.5 year review.
Gas and overall bowel scores with the NCFM plus LAFTI L10 blend
In 80 adults with IBS, a blend of NCFM and LAFTI L10 at 10 billion CFU a day for 8 weeks did not beat placebo on abdominal pain, the main outcome, but lowered flatus and a composite symptom score. The result belongs to the two-strain blend, not LAFTI L10 alone.
Mechanism of action
Gene activity in the human small intestine lining
In 7 healthy adults in a placebo-controlled crossover study, a single 6 hour dosing of L. acidophilus Lafti L10 changed gene networks that regulate basic processes of the lining in duodenal biopsies, with a pattern different from L. casei and L. rhamnosus. This is a short-term marker study, not a health outcome.
Gut and systemic immune cells in mice (animal work)
Mice fed LAFTI L10 for 14 days had more IgA, IL-10 and interferon-gamma producing cells in the small intestine, more active spleen cells and peritoneal macrophages, and no spread of bacteria to the spleen, liver or blood. These are animal findings only.
Cytokine responses in infants (marker work)
In the infant trial, 6 months of the strain lowered some cytokine responses to a tetanus vaccine antigen and to house dust mite, but did not change allergen-specific Th1 or Th2 responses. The clinical meaning of these marker shifts is unknown.
Clinical trials
Randomized, double-blind, placebo-controlled trial in Serbia; L. helveticus Lafti L10 (Lallemand Health Solutions) at 20 billion CFU a day or placebo for 14 weeks in winter; stated aims were the duration, severity and incidence of upper respiratory tract illness plus immune parameters, with no single primary outcome named in the abstract (the full text could not be read), and the duration result (p = 0.047) would not pass a correction for these three illness outcomes; the group's 2017 antibody and 2018 oxidative stress papers used the same 14 week design and do not say whether their athletes overlap with this sample; no trial registration and no funding statement in the abstract; authors from the University of Belgrade, the Torlak institute and the Sports Medicine Association of Serbia, with no Lallemand employees listed (Michalickova et al. 2016, Appl Physiol Nutr Metab)
39 elite athletes (20 probiotic, 19 placebo).
Episodes were shorter on the probiotic (7.25 versus 10.64 days, p = 0.047) with fewer symptoms (4.92 versus 6.91, p = 0.035). Severity and incidence did not differ. Most blood immune measures did not change; the CD4 to CD8 ratio differed between groups at 14 weeks, and self-rated vigor rose on the probiotic.
Randomized, double-blind, placebo-controlled trial by the same Belgrade group with the same 14 week design (the abstract prints the dose without its exponent; the group's other papers used 20 billion CFU a day); outcomes were total and bacteria-specific antibodies in serum and saliva; the papers do not say whether the athletes overlap with the 39 person trial; no funding statement or registration in the abstract (Michalickova et al. 2017, J Strength Cond Res)
30 athletes (24 men, 6 women), mean age about 24.
Total IgM rose in both groups with no between-group difference, and total IgG did not change. Total IgA fell on placebo in serum (15%) and saliva (35%) but not on the probiotic, and serum IgA to two L. rhamnosus strains and IgG to E. faecalis were lower on placebo than on the probiotic. These are antibody markers only; no illness outcome was reported.
Randomized, double-blind, placebo-controlled parallel trial in Serbia; L. helveticus Lafti L10 at 20 billion CFU a day or maltodextrin placebo for 14 weeks; outcomes were blood markers of oxidative stress and antioxidant defense; 22 athletes finished the study, and the paper does not say whether they overlap with the group's 39 and 30 athlete reports; Lallemand Health Solutions supplied the probiotic and placebo capsules, and funding came from the Serbian science ministry and Charles University; no company authors (Michalickova et al. 2018, J Hum Kinet)
22 male triathletes, cyclists and middle and long distance runners (10 probiotic, 12 placebo).
Malondialdehyde (interaction p = 0.039) and advanced oxidation protein products (interaction p = 0.037) fell in the probiotic group only. Superoxide dismutase fell on the probiotic (interaction p = 0.108), paraoxonase fell in both groups, and total antioxidant status, total oxidant status and the other measures did not change. These are blood markers only.
Randomized, placebo-controlled, double-blind parallel trial at the University of Florida; L. helveticus Lafti L10 at 5 billion CFU in one capsule a day or placebo for 6 weeks; primary outcome time to exhaustion at 85% of VO2max on a treadmill, with daily gastrointestinal and cold or flu symptom diaries; the authors reported no conflicts of interest and the abstract gives no funding source or registration (McDermott et al. 2024, Appl Physiol Nutr Metab)
28 generally healthy recreational runners who completed the study (14 per group), mean age 25.
Time to exhaustion at the final visit was lower on the probiotic than placebo (p = 0.01) because it rose on placebo (1344 to 1565 s) and did not change on the probiotic. The probiotic group completed fewer aerobic sessions a week (p = 0.02) at lower intensity (p = 0.007). Few stomach or cold symptoms were reported, with no difference between groups.
Randomized, placebo-controlled trial in Perth, Australia; newborns took 3 billion CFU of L. acidophilus LAVRI-A1 (Probiomics) or maltodextrin placebo daily for the first 6 months of life; outcomes were atopic dermatitis and other symptoms at 6 and 12 months and skin prick tests at 12 months; the 2.5 year follow-up paper names the strain LAFTI L10/LAVRI-A1; university authors, with no funding source stated in the abstracts read (Taylor et al. 2007, J Allergy Clin Immunol)
231 newborns of women with allergy were randomized; 178 completed supplementation, and 153 were reviewed at 2.5 years.
Skin allergy rates did not differ at 6 months (25.8% versus 22.7%, p = 0.629) or 12 months, and sensitization at 12 months was more common on the probiotic (p = 0.030). At 2.5 years, rates still did not differ (42% versus 34%), while the probiotic group had fewer stomach infections over the preceding 18 months (p = 0.023), a secondary finding.
Randomized, double-blind, placebo-controlled crossover study in the Netherlands; on separate days each volunteer took freeze-dried L. acidophilus Lafti L10, L. casei or L. rhamnosus every 30 minutes for 6 hours (about 52 billion L. acidophilus in total) or placebo, with a 2 week washout, followed by duodenal biopsies; funded by Dutch public genomics and bioinformatics programs, and the authors declared no conflicts (van Baarlen et al. 2011, Proc Natl Acad Sci U S A)
7 healthy nonsmoking adults, mean age 24.
Each strain changed a different set of gene networks that regulate basic processes in the lining of the small intestine compared with placebo. The study measured gene activity only, after a single day of dosing, and reported no health or symptom outcomes.