Salivary Secretory Immunoglobulin a secretion increases after 4-weeks ingestion of chlorella-derived multicomponent supplement in humans: a randomized cross over study
- Equal contributors
1 Faculty of Health and Sport Sciences, Ryutsu Keizai University, Ryugasaki, Ibaraki, Japan
2 Sports Research & Development Core, University of Tsukuba, Tsukuba, Ibaraki, Japan
3 Faculty of sport and health science, Ritsumeikan University, Kusatsu, Shiga, Japan
4 University of Tsukuba, Tsukuba, Ibaraki, Japan
Nutrition Journal 2011, 10:91 doi:10.1186/1475-2891-10-91Published: 9 September 2011
Chlorella, a unicellular green alga that grows in fresh water, contains high levels of proteins, vitamins, minerals, and dietary fibers. Some studies have reported favorable immune function-related effects on biological secretions such as blood and breast milk in humans who have ingested a chlorella-derived multicomponent supplement. However, the effects of chlorella-derived supplement on mucosal immune functions remain unclear. The purpose of this study was to investigate whether chlorella ingestion increases the salivary secretory immunoglobulin A (SIgA) secretion in humans using a blind, randomized, crossover study design.
Fifteen men took 30 placebo and 30 chlorella tablets per day for 4 weeks separated by a 12-week washout period. Before and after each trial, saliva samples were collected from a sterile cotton ball that was chewed after overnight fasting. Salivary SIgA concentrations were measured using ELISA.
Compliance rates for placebo and chlorella ingestions were 97.0 ± 1.0% and 95.3 ± 1.6%, respectively. No difference was observed in salivary SIgA concentrations before and after placebo ingestion (P = 0.38). However, salivary SIgA concentrations were significantly elevated after chlorella ingestion compared to baseline (P < 0.01). No trial × period interaction was identified for the saliva flow rates. Although the SIgA secretion rate was not affected by placebo ingestion (P = 0.36), it significantly increased after 4-week chlorella ingestion than before intake (P < 0.01).
These results suggest 4-week ingestion of a chlorella-derived multicomponent supplement increases salivary SIgA secretion and possibly improves mucosal immune function in humans.