Daily supplements of the probiotic Bifidobacterium lactis subsp lactis may reduce the risk of the common cold (upper respiratory tract infections or URTIs), reducing fevers by 72 percent and coughs by 62 percent.

In a earlier study done in China, small children who drank a mixture of probiotics twice a day during the winter and spring had fewer colds, needed fewer antibiotics, and missed fewer days of school than other children who drank plain milk instead. In that study published in the journal Pediatrics, the researchers report that compared to the placebo group, the Lactobacillus group had 53 percent fewer fevers, 41 percent fewer cough episodes, and 28 percent fewer runny noses.
Researchers have shown in some studies that probiotics can benefit those who are already ill with various conditions, and the bacteria are thought to boost the immune system’s response to invaders.

The Lactobacillus/Bifidobacterium group had even larger reductions in symptom rates: 72 percent fewer fevers, 62 percent fewer coughs, and 59 percent fewer runny noses.

In a Chr Hansen-sponsored study that gave 1 billion colony forming units (CFUs) of each strain or placebo to about 200 of US college students at Framingham State University, the study group experienced colds that lasted four days as opposed to six in the placebo group — a 34% reduction.

A recent study in Clinical Nutrition reported data from a randomized double-blind placebo-controlled trial with 465 active adults and indicated that supplements of B. lactis subsp lactis were associated with a 27% reduction in the risk of the common cold, compared to placebo.

“This study adds important new information regarding the effects of probiotic supplementation for respiratory illness,” they wrote in Clinical Nutrition . “The positive effects of probiotic supplementation appear to extend beyond individuals considered to have a higher susceptibility to illness.”

Study Details

Led by Allan Cripps from Griffith University, the researchers randomly assigned 465 healthy people with an average age of 35.5 to one of three groups: The first group received the BI-04 supplement (2 billion cfus); the second group received the combination probiotic of NFCM and Bi-07 (5 billion cfus); and the third group received placebo.

“The choice of the probiotics was made on the basis of previous data showing effects on immune-related outcomes in adults15 and in children,” explained the researchers.

After 150 days of intervention, the researcher found that the Bl-04 group had a 27% reduction in risk of URTIs, compared to placebo. The risk reduction as 19% in the NFCM and Bi-07 group, but this did not reach statistical significance.

In addition, the median time to an illness episode was delayed by 0.7 and 0.9 months in the Bl-04 and NCFM & Bi-07 groups, respectively, compared to placebo.

Another interesting observation made by the researchers was that participants in the NCFM & Bi-07 group reported a lower level of exercise intensity but substantially higher exercise duration. “The reason for the greater amount of physical activity undertaken by those in the NCFM & Bi-07 group may have been through the delayed time to illness,” they explained. “The findings from the current study indicate that NCFM & Bi-07 supplementation may be a useful nutritional adjunct to reduce the negative effects of illness on patterns of physical activity.”

Probiotics are defined as “live microorganisms which when administered in adequate amounts confer a health benefit on the host”. They are bacteria that help maintain the natural balance of organisms (microflora) in the intestines.

Many people use probiotics to prevent diarrhea, gas, and cramping caused by antibiotics. Antibiotics kill “good” (beneficial) bacteria along with the bacteria that cause illness. A decrease in beneficial bacteria leads to digestive problems and compromised immunity. Taking probiotics may help replace the lost beneficial bacteria and restore or even boost the immune system.

The 1.5 kilograms of bacteria that we each carry in our intestines have an enormous impact on our health and well being. The bacteria normally live in a sensitive equilibrium but if this equilibrium is disrupted our health could suffer.

Probiotics help people restore advantageous gut microflora in order to improve many aspects of their health. With balanced gut flora, the body’s immune system dramatically improves and is better able to produce necessary nutrients, in addition to other beneficial substances.

Probiotic strains enhance adhesion, mainly in large intestinal mucus. Treatment of intestinal mucus with probiotics significantly reduces the adhesion of pathogens. The ability to inhibit pathogen adhesion appears to depend on the specific probiotics and which pathogens are on the mucosal sites.

Some probiotics have been used for a very long time throughout history, such as in fermented foods and cultured milk products. These don’t appear to cause illness in any way. But more study is needed on the safety of probiotics in young children, the elderly, and people who have weak immune systems.

Sources:
Clinical Nutrition

Mae Chan holds degrees in both physiology and nutritional sciences. She is also blogger and and technology enthusiast with a passion for disseminating information about health.