Abstract
BackgroundImmunoglobulin A (IgA) secretion in saliva decreases with age and may be the cause of increased vulnerability of the elderly to respiratory infections. The effect of oral intake of lactic acid bacteria on salivary secretory IgA (SIgA) in the elderly has not been reported. The objective of this study was to demonstrate the acceleration of salivary SIgA secretion by oral intake of Lactobacillus pentosus strain b240 (b240) in the elderly.ResultsA total of 80 healthy elderly individuals were randomly allocated to either an intervention (i.e., b240) or a control (i.e., placebo) group. The elderly individuals in the b240 group were given a sterile water beverage (125 mL) containing heat-killed b240 (4 × 109 cells), while those in the placebo group were given only a sterile water beverage (125 mL); both groups received their respective beverages once daily for 12 weeks. Saliva was collected before initiation of the study and every 2 weeks thereafter. Saliva flow rate and SIgA concentration were determined, and the SIgA secretion rate was calculated. The mean salivary SIgA secretion rate in the b240 group steadily increased until week 4 (exhibiting a 20% elevation relative to that at week 0), and then remained stable until week 12. Changes in SIgA secretion rate over the intervention period were significantly greater in the b240 group than in the placebo group. The treatment groups exhibited no significant differences in adverse events.ConclusionsOral intake of L. pentosus strain b240 for 12 weeks significantly accelerated salivary SIgA secretion, thereby indicating its potential utility in the improvement of mucosal immunity and resistance against infection in the elderly.
Highlights
Immunoglobulin A (IgA) secretion in saliva decreases with age and may be the cause of increased vulnerability of the elderly to respiratory infections
The salivary secretory IgA (SIgA) secretion rate at week 0 was subject to wide inter-individual variation
The average SIgA concentrations were higher at weeks 2, 4, and 12 (P = 0.010, P = 0.030, and P = 0.037, respectively) and the average SIgA secretion rates were higher at weeks 4 and 12 (P = 0.024 and P = 0.042, respectively)
Summary
Immunoglobulin A (IgA) secretion in saliva decreases with age and may be the cause of increased vulnerability of the elderly to respiratory infections. The effect of oral intake of lactic acid bacteria on salivary secretory IgA (SIgA) in the elderly has not been reported. The mucosal membranes covering the oral cavity, gastrointestinal, respiratory, and genitourinary tracts are continuously exposed to pathogenic microorganisms and they are protected by a large and highly specialized innate and adaptive mucosal immune system [1]. The adaptive humoral immune defense at mucosal surfaces is to a large extent mediated by secretory immunoglobulin A (SIgA), the predominant immunoglobulin class in human external. SIgA secretion in saliva decreases with age [14,15,16,17,18], and may lead to an increased risk of respiratory infections. Improving or slowing the agerelated decline of salivary SIgA may be beneficial for improving the health of the elderly
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
