Although there have been previous studies on the effect of probiotics on the duration of colds and severity of symptoms, this is the first study to investigate the effect of probiotic strains on HRQL during upper-respiratory infections, taking into account duration, symptom severity and functional impairment—all important factors of HRQL. “HRQL is subjectively assessed by the patient and most simply defined as ‘the component of overall quality of life that is determined primarily by the person’s health and that can be influenced by clinical interventions,’” Smith says.
An article detailing the results of the study, “Effect of Lactobacillus rhamnosus GG (LGG®) and Bifidobacterium animalis ssp lactis (BB-12®) on health-related quality of life in college students with upper respiratory infections,” was published in the October 2012 issue of the British Journal of Nutrition. “We know that certain probiotic strains support immune health and may improve health-related quality of life during upper-respiratory infections,” says Smith. “This double-blind study assessed how probiotic supplementation affects the duration and severity of symptoms, and the impact of symptoms on the daily life of infected students.”
The study found that while all students caught colds at roughly the same rate, the students who took the probiotic supplementation experienced:
- A duration of colds that was two days shorter (four days vs. six days)
- Symptoms that were 34% less severe and
- A higher quality of life that resulted in fewer missed school days (15 vs. 34 missed by students taking the placebo).
What makes probiotics so effective in treating symptoms of upper-respiratory infections? “Cold symptoms like a stuffy nose and sore throat are the body’s inflammatory response toward a virus, not a direct action of the virus itself,” explains Smith. “Probiotic microorganisms may soften your immune system’s reaction by reducing your body’s inflammatory response.”
The Take-Away for the Public:
“If cost is not an issue, then otherwise healthy persons who are especially stressed, sleep-deprived or living in close quarters [such as a college dormitory] could supplement daily during cold season with both LGG and BB12 to improve their quality of life if/when they do get a cold,” says Smith. However she cautions that not all probiotics are created equal. “The study supports the combination of LGG and BB12—two very specific strains of probiotics. These two strains also are in a number of supplement-type products that are available over the counter,” she says, “but consumers need to read the label to be sure that the product contains Lactobacillus rhamnosus GG [LGG] and Bifidobacterium animalis lactis BB12 [BB12]. There also are some yogurts that contain LGG and/or BB12 but check the labels, since companies change the probiotics strains often.”
“People should also recognize that probiotics are not for everyone,” Smith continues. “Those considering probiotic supplementation should consult with their physician first.”
From the University of Medicine and Dentistry of New Jersey- School of Health Related Professions, Newark, N.J.: Tracey J. Smith, PhD, RD, Adjunct Assistant Professor, Department of Nutritional Sciences; Diane Rigassio-Radler, PhD, RD, Associate Professor, Department of Nutritional Sciences; Robert Denmark PhD, Interim Assistant Dean for Research; and Riva Touger-Decker, PhD, RD, Chair, Department of Nutritional Sciences.
From the U.S. Army Research Institute of Environmental Medicine, Natick, Mass.: Timothy Haley, MD, Office of Medical Support and Oversight.
This study was funded by Chr. Hansen A/S, Hoersholm, Denmark.
About the University of Medicine and Dentistry of New Jersey
The University of Medicine and Dentistry of New Jersey (UMDNJ) is New Jersey’s only health sciences university with more than 6,000 students on five campuses attending three medical schools, the State’s only dental school, a graduate school of biomedical sciences, a school of health related professions, a school of nursing and New Jersey’s only school of public health. UMDNJ operates University Hospital, a Level I Trauma Center in Newark, and University Behavioral HealthCare, which provides a continuum of healthcare services with multiple locations throughout the State.