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.

BackgroundThe present study was conducted to investigate the possible association between gut microbes and immunity among healthy middle-aged and elderly individuals in southwest China. A total of 148 healthy adults aged ≥ 50 years were divided into two age groups: middle-aged group (50–59 years; n = 67, 54.13 ± 3.32) and elderly group (≥ 60 years; n = 81, 64.70 ± 3.93). Blood samples were collected to measure serum immune and biochemical indices. Gut microbiota compositions of the groups were characterized on the basis of faecal DNA using 16S rRNA gene sequencing.ResultsAmong the detected gut microbes, the presence of Alistipes was negatively correlated with age in both groups. In the middle-aged group, age was negatively correlated with the presence of Desulfovibrio and Faecalibacterium. In the elderly group, Coprococcus was present at significantly higher levels; age was negatively correlated with the presence of Lachnobacterium, Oxalobacter and the Chao index, whereas positively correlated with the presence of Sutterella. In the middle-aged group, the presence of Bacteroidetes was positively correlated with serum immunoglobulin G (IgG) levels and the percent of CD8+ T cells and negatively correlated with the CD4+/CD8+ ratio; the presence of Firmicutes was negatively correlated with IgM levels; Bacteroidetes/Firmicutes ratio was positively correlated with IgG and IgM levels and Simpson index was negatively correlated with the percent of CD8+ T cells and positively correlated with CD4+/CD8+ ratio. In the elderly group, the presence of Verrucomicrobia (identified as genus Akkermansia) was positively correlated with IgA levels and the percent of CD8+ T cells and negatively correlated with the percent of CD4+ T cells and CD4+/CD8+ ratio; the Chao index and observed species were positively correlated with IgA levels.ConclusionsThese results indicated that ageing could significantly correlate with the composition of gut microbiota in terms of quantity and quality. Changes in gut microbiota caused by ageing, characterized by decreased Bacteroidetes levels, might be associated with immunosenescence among healthy middle-aged and elderly people in southwest China.Electronic supplementary materialThe online version of this article (10.1186/s13099-018-0231-3) contains supplementary material, which is available to authorized users.

ChiCTR-OOC-16010271.

Recent studies have demonstrated that antibiotics/or probiotics administration in early life play key roles on modulating intestinal microbiota and the alterations might cause long-lasting consequences both physiologically and immunologically. We investigated the effects of early life ceftriaxone, vancomycin and Bifidobacterium bifidum TMC3115 (TMC3115) treatment on intestinal microbiota and immunity both in neonates and adults even after termination of antibiotics exposure. We found that ceftriaxone and vancomycin, but not TMC3115, significantly altered the intestinal microbiota, serum total IgE level, and the morphology and function of the intestinal epithelium in the neonatal mice. In the adult stages, the diversity and composition of the intestinal microbiota were significantly different in the antibiotic-treated mice, and ceftriaxone-treated mice exhibited significantly higher serum total IgE and OVA-specific IgE levels. TMC3115 significantly mitigated the alteration of intestinal microbiota caused by ceftriaxone not vancomycin. Antibiotics and TMC3115 can differently modulate intestinal microbiota and SCFAs metabolism, affecting the development and function of the immunity and intestinal epithelium to different degrees in neonatal mice. Neonatal ceftriaxone-induced abnormal intestinal microbiota, immunity and epithelium could last to adulthood partly, which might be associated with the enhancement of host susceptibility to IgE-mediated allergies and related immune responses, TMC3115 may protect against the side effects of antibiotic treatment, at least partly.

This study aimed to demonstrate whether exposure to bifidobacteria during early life influences immunity and alleviates the risk of immunoglobulin E (IgE)-mediated allergies in adulthood. BALB/c neonatal mice (n=54) were administered with a lyophilised cell preparation of Bifidobacterium bifidum TMC3115 (TMC3115) for 3 weeks. Following the intervention, the mice were immunised with intraperitoneal ovalbumin (OVA). The morphology and function of the intestinal epithelium were determined using histopathological examinations. Intestinal microbiota was detected using quantitative PCR and characterised using next-generation sequencing of 16S rRNA genes from faecal DNA. Caecal short-chain fatty acids (SCFAs) were measured using gas chromatography-mass spectrometry. Serum levels of tumour necrosis factor (TNF)-α, interleukin (IL)-6, IL-10, and immunoglobulin E (IgE) and the percentage of splenic CD4+ T cells were examined using enzyme-linked immunosorbent assay and flow cytometry, respectively. TMC3115 did not significantly affect body weight, and cause any severe systemic inflammation or other clinical symptoms among the neonatal or adult mice, although the crypt depths and Muc2-positive cells in some intestinal segments of neonatal mice were significantly lower than control. Oral TMC3115 administration significantly increased faecal microbial diversity, relative abundance of Bacteroidetes and caecal SCFAs production in neonatal mice. Following the intervention, neonatal mice treated with TMC3115 exhibited less increase in serum IgE levels induced by OVA in adults and significantly higher TNF-α and IL-10 levels than in control. Our findings indicate that the oral administration of bifidobacteria, particularly certain strains, such as TMC3115, during early life could alleviate the risk of IgE-mediated allergies in adult host animals. Modifications of intestinal microbiota, SCFAs metabolism and anti-inflammatory cytokine IL-10 production by bifidobacteria may at least in part be a key mechanism underlying the effect of bifidobacteria on the IgE-mediated immune sensitivity of hosts to attacks by allergens at both neonatal and adult stages.

Full paper Effect of heat-inactivated Lactobacillus paracasei N1115 on microbiota and gut-brain axis related molecules

Our data are complementary to public data sources, and the CNV map may facilitate in the identification of pathogenic CNVs and further biomedical research studies involving the Han Chinese population.

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