Probiotics Join the Fight Against Flu

Guest BloggerClinical Corner, Microbiome Environment

Like winter, flu season is etched on our calendars.

This year many countries are reporting high flu activity and low success of vaccines against the dominant H3N2 strain, according to the Centers for Disease Control and Prevention (CDC).

Because viruses mutate over time, the formulated vaccines don’t always prevent the flu. Better solutions are needed. The respiratory illness caused and the danger posed to the most fragile among us suggests that anything that bolsters the mucosal and systemic immune systems would be welcomed.

Enter probiotics. We already know their value in stemming respiratory tract infections in children, adults, and elderly individuals. It’s not farfetched to surmise that probiotics may also play in the flu virus sandbox.

Probiotics and influenza

Only a few probiotics have been studied in this regard but with positive results.

  • Lactobacillus casei: a strain conferred protection against influenza A virus infection in one recent study with mice. Even better, the mice showed immunity against future secondary infection.
  • Lactobacillus plantarum: a strain found in kimchi (delicious Korean fermented cabbage) was given to mice beset with lethal flu viruses in a new 2018 study. Treated mice showed reduced viral replication in their lungs as well as better survival rates.
  • Bacillus subtilis: a new microbial peptide called P18 produced by a strain of these bacteria showed protective effects against the influenza virus and even complete inhibition at high concentrations in mice in this 2017 study.

Another way probiotics make sense may be by enhancing the power of the actual vaccine. A recent meta-analysis looked at 9 trials which including a total of 623 participants: those taking probiotics or prebiotics were better protected against several flu types including H1N1, H3N2 and B strains.  The data suggest that synbiotics boost immunity by impacting antibody development in adults given the flu vaccines. The full review is available here in October 2017 issue of Nutrients journal.

With more weeks to go in the flu season, it’s not too late to get vaccinated to lessen the severity of symptoms (and risk of death.)

Follow that up with rest, good hygiene and probiotics. Kimchi is worth a try even if both North and South Korea are reporting flu outbreaks ahead of the Winter Olympics. Go figure.