Probiotics are known to provide benefits related to preventing intestinal infection and inflammation; however, a recent challenge-model study has shown that DuPont Nutrition & Health’s (Madison, WI) proprietary probiotic strain Bifidobacterium lactis BI-04 (in the form of commercially available Howaru Protect Adult) has the potential to help maintain healthy respiratory immune function. The common cold, which is usually caused by rhinovirus infection, is one of the most prevalent diseases across the globe, but there are few studies on the effects of probiotics for respiratory ailments, the company says. In this randomized, double-blind, placebo-controlled study, researchers sought to determine the extent to which BI-04 may reduce the incidence of upper respiratory illness.
The study, published in Beneficial Microbes1 and sponsored by DuPont and the University of Virginia, investigated the effect of BI-04 on 190 healthy, rhinovirus-challenged adults. Participants in the study group were given 2×109 CFU BI-04 plus 1 g of sucrose as a carrier per day, and the control group was given 1 g of sucrose in sachet form as a placebo. The subjects were instructed to consume BI-04 daily for one month, during which time researchers observed innate immune responses and presence of rhinovirus in the nostrils. Using nasal washes, the study authors analyzed virus and immune markers before and after supplementation with either BI-04 or the placebo, and then again for five days after the introduction of the rhinovirus challenge using the Wisconsin Upper Respiratory Symptom Survey WURSS-21 questionnaire. Participants were instructed to continue taking either the supplement or placebo for the five days that researchers collected specimens.
Compared to the placebo, the probiotic supplement had an effect on the presence of the virus in the nostrils. In particular, researchers observed a decreased amount of rhinovirus in nasal washes during infection in the intervention group. Increases in the concentration of the inflammatory cytokine chemokine ligand 8 (CXCL8) in nasal lavage were statistically significant only for the control group, and CXCL8 response to virus infection over the course of five days post-virus challenge was significantly reduced in the study group. The researchers concluded that supplementation with BI-04 has a modest effect on the inflammatory response to rhinovirus infection, and has a noted effect on rhinovirus replication. There was no effect observed on symptoms or incidence of infection assessed by isolation of the virus.
While the results of this study suggest BI-04’s potential positive impact on reducing respiratory illnesses, more studies are needed to build on these findings, the researchers say. Ron Turner, MD, University of Virginia School of Medicine, says: “The effects observed in this short-term, well-controlled study were modest and may only partially explain reduction in illness reported in the natural setting. However, the results do suggest the utility of further investigations of the effect of specific probiotics on innate immune function in the human host.”
According to a press release, the challenge model is a unique approach in that it provides researcher an opportunity to characterize the interaction between the infection and host responses under controlled conditions in human subjects using probiotics. DuPont claims that BI-04 is the first probiotic strain that has shown efficacy in modulating immune response in a well-controlled rhinovirus challenge model.
In addition to Howaru Protect Adult, DuPont’s line of clinically researched probiotics for immune and digestive health includes Howaru Protect EarlyLife, Howaru Protect Kids, Howaru Protect Sport, and Howaru Protect Senior.
- Turner RB et al. “Effect of probiotic on innate inflammatory response and viral shedding in experimental rhinovirus infection—a randomized controlled trial.” Beneficial Microbes, vol. 8, no. 2 (April 2017): 207-215