A growing body of research indicates that
oral administration of bacteria (such as probiotics) can exhibit a protective effect against
influenza A (H1N1)
viral infection in mice. In the present study, we used a mouse model to examine whether
oral administration of
Immulina(®), a commercial extract from the cyanobacteria Arthrospira (Spirulina) platensis, can reduce the severity of illness resulting from
influenza A (H1N1)
viral infection. The main active compounds within
Immulina(®) are bacterial Braun-type
lipoproteins that activate innate immune cells through a
toll-like receptor (TLR) 2-dependent pathway. Mice that were fed
Immulina(®) for 30 days before and 21 days after
infection with
influenza A (H1N1) virus exhibited a statistically significant reduction in the severity of
infection. Compared to the control group,
Immulina(®)-fed mice exhibited less
weight loss, increased appetite, decreased clinical signs of disease, and lower lung histopathology scores. The results from the present study adds to the increasing evidence that
oral administration of bacterial components that activate innate immune cells, whether derived from a bacterial preparation (probiotics or cyanobacteria) or from plant material containing endophytic bacteria, can exhibit a protective effect against
influenza A (H1N1)
viral infection.