Probiotics for Healthy People

Do probiotics offer any benefits to healthy people? Accumulating research suggests they do.

Healthy people want to stay healthy. Foods that may give people an extra edge against getting sick are a desirable option.

A new study by West et al. 2013 found that Bifidobacterium lactis Bl-04 reduced the risk by 27% of healthy, physically active adults getting an upper respiratory tract infection.

This study was well-done:  a randomized, double-blinded, placebo-controlled 3-arm study of 465 healthy active men and women. The 3 tested interventions were:

  1. B. lactis Bl-04 (2×109/d)
  2. L. acidophilus NCFM + B. lactis Bi-07 (5×109 each/d)
  3. Placebo

The primary outcome of the study (determined before the study was conducted) was the incidence, severity and duration of upper respiratory tract infections. Results:  Bl-04 reduced incidence of URTI, but NCFM+Bi-07 did not. However, both probiotic preparations did reduce the median time for an upper respiratory tract illness episode to occur: 3.2 months in the Bl-04 group; 3.4 months in the NCFM+Bi-07 group; 2.4 months in the placebo group.

The researchers tracked gastrointestinal illness episodes, but the incidence was too low to analyze the data.

The authors’ state:  “Given the economic and productivity losses and personal costs associated with URTI, the significant risk reduction and findings from this study are promising for healthy physically active individuals in relation to URTI.”

The findings of this new study are consistent with the conclusions of a previous meta-analysis on the effect of probiotics on incidence of URTI (Hao et al. 2011). Accumulating evidence among different strains of probiotics and in different healthy populations increases confidence that probiotics may be a useful addition to a healthy person’s diet.

Reducing URTIs is not the only potential benefit of probiotics to healthy people. Other benefits from studies done in healthy people include:

  • Improved tolerance to lactose in lactose maldigesters (de Vrese et al. 2001)
  • Normalized intestinal transit time (Miller and Ouwehand, 2013)
  • Reduced plasma LDL levels  (Jones, et al. 2012; Amar et al. 2013; Guo et al. 2013)
  • Regulation of the immune system  (Chu and Mazmanian. 2013; Brestoff and Artis. 2013)
  • Improved symptoms of irritable bowel syndrome (Hoveyda et al. 2009). Some may argue that people with IBS are not healthy, but IBS is not a disease (it’s a syndrome) and with estimates of IBS in 15-20% of the US population, many active people could benefit from a dietary approach to managing their symptoms.
  • Excessive infant crying time (Sung et al. 2013)

And for people who are generally healthy but are taking antibiotics for minor infections (such as ear infections), probiotics have been shown to:

  • Reduce antibiotic prescriptions (Hao 2012)
  • Reduce incidence of antibiotic-associated diarrhea (Hempel et al. 2012)


Amar J, Lange C, Payros G, et al. Blood microbiota dysbiosis is associated with the onset of cardiovascular events in a large general population: the D.E.S.I.R. study. PLoS One. 2013;8(1):e54461. PubMed PMID: 23372728. Pubmed Central PMCID: 3555817.

Brestoff JR, Artis D. Commensal bacteria at the interface of host metabolism and the immune system. Nat Immunol. 2013 Jul;14(7):676-84. PubMed PMID: 23778795.

Chu H, Mazmanian SK. Innate immune recognition of the microbiota promotes host-microbial symbiosis. Nat Immunol. 2013 Jul;14(7):668-75. PubMed PMID: 23778794.

de Vrese M, Stegelmann A, Richter B, Fenselau S, Laue C, Schrezenmeir J. Probiotics–compensation for lactase insufficiency. Am J Clin Nutr. 2001 Feb;73(2 Suppl):421S-9S. PubMed PMID: 11157352.

Hao Q, Lu Z, Dong BR, Huang CQ, Wu T. Probiotics for preventing acute upper respiratory tract infections. Cochrane database of systematic reviews. 2011 (9):CD006895. PubMed PMID: 21901706.

Hempel S, Newberry SJ, Maher AR, Wang Z, Miles JN, Shanman R, Johnsen B, Shekelle PG. Probiotics for the prevention and treatment of antibiotic-associated diarrhea: a systematic review and meta-analysis. JAMA. 2012 May 9;307(18):1959-69.

Jones ML, Martoni CJ, Parent M, Prakash S. Cholesterol-lowering efficacy of a microencapsulated bile salt hydrolase-active Lactobacillus reuteri NCIMB 30242 yoghurt formulation in hypercholesterolaemic adults. Br J Nutr. 2012 May;107(10):1505-13. PubMed PMID: 22067612.

Miller LE, Ouwehand AC. Probiotic supplementation decreases intestinal transit time: meta-analysis of randomized controlled trials. World J Gastroenterol. 2013 Aug 7;19(29):4718-25. PubMed PMID: 23922468. Pubmed Central PMCID: 3732843.

van Baarlen P, Wells JM, Kleerebezem M. Regulation of intestinal homeostasis and immunity with probiotic lactobacilli. Trends Immunol. 2013 May;34(5):208-15. PubMed PMID: 23485516.

West NP, Horn PL, Pyne DB, Gebski VJ, Lahtinen SJ, Fricker PA, Cripps AW.Probiotic supplementation for respiratory and gastrointestinal illness symptoms in healthy physically active individuals. Clin Nutr. 2013 Oct 10. doi:pii: S0261-5614(13)00261-6. 10.1016/j.clnu.2013.10.002. [Epub ahead of print]