study: probiotics and the impact of flu

Written by Kristy Coleman

Look, us mere mortals never really get to find out what is going on in the world of science. Well, not unless it’s (sometimes) sensationalised in the press. So, we wanted to bring you a snapshot of the latest science to whet your appetite to find out more if it’s something that piques your interest. Or simply to keep you all in the “gut world” loop. Remember most of the studies are VERY new science, so keep your critical thinking cap on!

Background

As much as we’d love to say probiotics can prevent you from getting sick, it simply isn’t as straightforward as that. Your gut and your immune system are inexplicably linked. 70% of your immune system is found there (read more about your immune system and how it is made, not born).

There have been some interesting developments on the research side of things this year. One study looked at whether administering a probiotic had an effect on the outcomes of flu-like respiratory infections.

Type of study

This study analysed two meta-analysis studies, which produced a cohort of 329,256 individuals. The study was done in the US to assesses the effectiveness of probiotics and respiratory tract infections (RTIs).

Study Findings

Overall, the study found that it did reduce the number of RTI and the number of days with symptoms and the need for antibiotics. The study concluded that if this was applicable on a large population scale, it would have significant cost savings on health care systems and employers. The results indicated that at-risk populations, such as children and those who share an indoor environment, could benefit from a daily probiotic.

Study Limitations

As always, we like to dig a bit deeper into the motives behind all research studies and look for any conflict of interest. You will find that generally, there is some degree of conflict. Whether it’s a researcher acting as an advisor to big corporates or where funding comes from. In this particular study, several of the researchers declared significant conflicts of interest. From working for pharmaceutical corporates to food companies making probiotic foods.

In addition, different probiotic strains (gut more info about probiotic strains), genus, and species have a different effect. This study lumped all probiotics together, to be of real use, you’d want to know the effect of each strain.

While the author’s concluded this could have cost-saving implications. The cost of probiotic supplementation is not accounted for, which undermines the cost-saving claims.

Conclusion

As much as we would love to say that probiotics and the flu are linked. And that supplements and food rich in probiotics can prevent the flu or cure you getting ill, we simply don’t have enough robust evidence to make such a bold claim. As there are so many factors involved in determining whether you are more or less susceptible to picking things up. We must also remember the importance of stress is a key player in how well your immune system works. So you could eat all the probiotic foods but still be super stress and succumb to a cold. Which is OK – your immune system is doing its thing. However, for vulnerable groups, this could be a really interesting development. But more research on specific strains and cost implications is needed before we are prescribing probiotics to prevent specific conditions.

About the Author

Kristy Coleman is a Nutrition Practitioner, registered with the CNHC and a member of BANT (British Association for Nutrition and Lifestyle Medicine). Kristy specialises in gut health and runs a private nutritional therapy clinic in London, provides nutrition workshops, and writes for several health and wellbeing publications.