10/02/2026
🦠 Can probiotics help with viral infections — or is it hype?
Probiotics are often marketed as immune boosters, especially during cold and flu season. But that framing oversimplifies what’s really happening.
Probiotics don’t boost immunity in a generic way. Instead, they influence immune responses at key entry points, particularly along the oral–lung–gut axis 🫁🦷🌱
The immune system isn’t organised into individual organs, but into interconnected networks. Signals from gut microbes influence immune activity in the lungs, while the oral microbiome plays a frontline role in respiratory defence.
Viral respiratory infections are commonly associated with:
• Disrupted gut and oral microbiota 🦠
• Reduced microbial diversity 🌈
• Impaired mucosal barrier function
• Exaggerated inflammatory responses 🔥
When these systems are out of balance, immune responses can become either sluggish or excessive, worsening illness and delaying recovery.
Rather than directly attacking viruses, probiotics help stabilise these microbial ecosystems and support more balanced immune responses ⚖️
How probiotics support viral defence:
• Support mucosal immunity at the point of entry (mouth, throat, nose) 👄
• Regulate inflammation rather than overstimulating the immune system
• Support barrier integrity in the gut and oral tissues
• Produce beneficial metabolites (postbiotics) that signal immune cells, including in the lungs 🧬
Human studies show that specific probiotic strains can:
• Reduce the frequency of common viral respiratory infections (BLISK12 is patented for its effect against COVID)
• Shorten symptom duration ⏳
• Reduce secondary infections, particularly in children, older adults and immunocompromised populations
Where Zestt fits in 🌿
At Zestt, our approach to immune resilience is multi-layered. We don’t view probiotics as a standalone solution; we combine probiotics, prebiotics and plant bioactives to support immune regulation and pro-resolving pathways, including those associated with M2 macrophage activity (as seen in Zestt Breathe+).
The bottom line:
Probiotics won’t prevent every infection or eliminate viruses. But evidence suggests they can help shape the microbial and immune environments that influence how often you get sick, how severe symptoms become and how quickly you recover 💪