Probiotic versus placebo

Researchers randomly assigned 231 healthy college students to take a probiotic dietary supplement or a placebo (no probiotic) once daily for 12 weeks. The probiotic provided a minimum daily dose of one billion colony-forming units (CFUs) of two probiotic bacteria: Lactobacillus rhamnosus LGG (LGG) and Bifidobacterium animalis subspecies lactis BB-12. A colony-forming unit is one live, viable bacterium that can reproduce.

Neither the students nor the researchers knew who received the probiotic or the placebo, and 198 students (86%) completed the entire 12-week study. Study participants provided information on whether, and how severely, they experienced symptoms of upper respiratory tract infection, as well as missed days of school and work throughout the research period.

Compared with students taking the placebo, those who received the probiotic supplement:

• experienced a shorter median duration (by two days) of upper respiratory tract infections when they caught a cold,
• had 34% less severe symptoms when they become sick, and
• missed 0.2 fewer school days.

Picking a probiotic, and other ways to nix a cold

This study was small and of short duration, but still, it points to a relatively simple thing that may help college kids bounce back faster when they catch a cold. Our tips on picking a probiotic, along with other cold-quashing ideas can help you keep the people in your life healthier.

• Pick a product. To use a probiotic to bolster defenses against the cold, make sure the product contains the right bacteria, in the right numbers. This study only looked at two specific bacteria. It is not known whether other probiotic strains would provide the same benefit.
• Address bigger issues. A probiotic cannot overcome all of the issues that make college students more susceptible to upper respiratory infections. Addressing these factors—inadequate sleep, stress, close living quarters, lack of exercise, and poor dietary habits—also should be a priority.
• Take simple measures. Though we often can’t change the fact that students live in close quarters, basic hygiene is key to avoiding colds in these situations. Frequent hand washing, use of hand sanitizing products, and reminding young adults not to touch their faces during the day will go a long way toward keeping them healthy.
• Know your illness. Influenza is a systemic illness, and is much more serious than a cold. If you have a fever above 100 degrees, body aches, dizziness, nausea, vomiting, diarrhea, chills, or fatigue, call your doctor for advice on whether you need to come into the office, and what steps you can take to recover from the flu.

(Br J Nutr 2013;109:19992007)