Yogurt supplemented with probiotics can protect the healthy elderly from respiratory infections: A randomized controlled open-label trial

Abstract

PurposeTo evaluate whether yogurt supplemented with a probiotic strain could protect middle-aged and elderly people from acute upper respiratory tract infections (URTI) using a randomized, blank-controlled, parallel-group design.Patients and methodsTwo hundred and five volunteers aged ≥45 years were randomly divided into two groups. The subjects in the intervention group were orally administered 300 mL/d of yogurt supplemented with a probiotic strain, Lactobacillus paracasei N1115 (N1115), 3.6×107 CFU/mL for 12 weeks, while those in the control group retained their normal diet without any probiotic supplementation. The primary outcome was the incidence of URTI, and changes in serum protein, immunoglobulins, and the profiles of the T-lymphocyte subsets (total T-cells [CD3+], T-helper cells [CD4+], and T-cytotoxic-suppressor cells [CD8+]) during the intervention were the secondary outcomes.ResultsCompared to the control group, the number of persons diagnosed with an acute URTI and the number of URTI events significantly decreased in the intervention group (P=0.038, P=0.030, respectively). The risk of URTI in the intervention group was evaluated as 55% of that in the control group (relative risk =0.55, 95% CI: 0.307–0.969). The change in the percentage of CD3+ cells in the intervention group was significantly higher than in the control group (P=0.038). However, no significant differences were observed in the total protein, albumin, globulin, and prealbumin levels in both groups (P>0.05).ConclusionThe study suggested that yogurt with selected probiotic strains such as N1115 may reduce the risk of acute upper tract infections in the elderly. The enhancement of the T-cell-mediated natural immune defense might be one of the important underlying mechanisms for probiotics to express their anti-infective effects.

Possible correlation between gut microbiota and immunity among healthy middle-aged and elderly people in southwest China

“…Immune functions were assessed on the basis of lymphocyte subsets detected using flow cytometry (BD FACSCalibur, BD, Inc., USA), including total T cells (CD3 + ), helper T cells (CD4 + ) and cytotoxic T cells (CD8 + ) (CD4-FITC/CD8-PE/CD3-PerCP, BD, Inc., USA), and immunoglobulin (Ig)A, IgG and IgM levels detected using an automatic specific protein analyser (IMMAGE 800, Beckman Coulter, Inc., USA). Nutritional status was reflected by glucose, total cholesterol (TC), triglycerides (TG), high-density lipoproteins (HDL), low-density lipoproteins (LDL), Uric acid and Blood urea nitrogen detected using automatic biochemical analyser [ 17 ]. All analyses were conducted using standard procedures approved by the West China Medical Detection Institute, Sichuan University (Chengdu, China).…”

Initial success in the identification and management of the coronavirus disease 2019 (COVID-19) indicates human-to-human transmission in Wuhan, China

“…A TMPRSS2 inhibitor blocked entry and might constitute a treatment option. Other studies have also shown that yogurt and probiotics can help prevent lung infections in the elderly [79]. Since the outbreak of SARS in 2003, China's scientific research capacity in the field of preventive medicine has been dramatically improved.…”

Antibacterial Activity of Lactobacillus Strains Isolated from Mongolian Yogurt against Gardnerella vaginalis

“…Zhu et al [21] showed that bioyogurt and the probiotics that it contains were capable of inhibiting specific periodontal pathogens. Yogurt with selected probiotic strains such as N1115 may reduce the risk of acute upper tract infections in the elderly [22].…”