Enhanced vaccination effect against influenza by prebiotics in elderly patients receiving enteral nutrition

AimWe investigated the effect of prebiotics on the immunological response after influenza vaccination in enterally fed elderly individuals. The intervention group was given an enteral formula containing lactic acid bacteria-fermented milk products. In addition, two different types of other prebiotics, galacto-oligosaccharide and bifidogenic growth stimulator, were also given. The two prebiotics improved intestinal microbiota differently. In a control group, a standard formula without prebiotics was given. MethodsAn enteral formula with (intervention group [F]) or without (control group [C]) prebiotics was given through percutaneous endoscopic gastrostomy to elderly participants for 10 weeks. Influenza vaccine was inoculated at week4. Nutritional and biochemical indices, intestinal micro bacteria and immunological indices were analyzed. ResultsThe Bifidobacterium count in groupsF and C at week0 was 6.41.9 and 6.6 +/- 3.0 (log10 [count/g feces]), respectively. Although the count in groupC decreased at week10, the count in groupF increased. The Bacteroides count in groupF increased from 10.7 +/- 0.9 to 11.4 +/- 0.5, but decreased in groupC from 11.2 +/- 0.2 to 10.7 +/- 0.4. Although the enhanced titers of H1N1, H3N2 and B antigens against the vaccine decreased thereafter in groupC, these enhanced titers in groupF could be maintained. ConclusionOur findings suggest that prebiotics affect the intestinal microbiota and might maintain the antibody titers in elderly individuals. Geriatr Gerontol Int 2016; 16: 205-213.