Heat-inactivated Lacticaseibacillus paracasei N1115 alleviates the damage due to brain function caused by long-term antibiotic cocktail exposure in mice.

Critical development period of intestinal microbiota occurs concurrently with brain development, and their interaction is influenced by the microbiota-gut-brain axis. This study examined how antibiotics exposure affected gut microbiota and brain development and analyzed the possible benefits of heat-inactivated Lacticaseibacillus paracasei N1115 (N1115). Thirty neonatal male mice were randomly divided into three groups and treated with sterilized water (control), an antibiotic cocktail (Abx), or antibiotics plus heat-inactivated N1115 (Abx + N1115) for 84 days. We found that while the mRNA levels of GABAAα1, GABAb1, and glucocorticoid receptor (GR) in the hippocampus and brain-derived neurotrophic factor (BDNF), GABAAα1, GABAb1, and nerve growth factor (NGF) in the prefrontal cortex were higher, the mRNA levels of 5-HT1A were lower in the Abx group. The Abx + N1115 group had lower mRNA levels of GABAAα1, GABAb1, and GR in the hippocampus and BDNF, GABAb1, and NGF in the prefrontal cortex than the Abx group. The latency period was longer in the Morris water maze test while longer rest time was seen in tail suspension test in the Abx group than the control and Abx + N1115 groups. In the open field test, the moving time and distance of the Abx group were reduced. Further, the alpha-diversity indexes of the Abx and Abx + N1115 groups were significantly lower than the control. Further, long-term exposure to antibiotics disrupted the intestinal microbiota as evidenced by decreased Bacteroides, Firmicutes, and Lactobacillus, and increased Proteobacteria and Citrobacter. However, N1115 significantly decreased the abundance of Citrobacter when compared with those in the Abx group. These results indicate that antibiotics can substantially damage the intestinal microbiota and cognitive function, causing anxiety and depression, which can be alleviated by heat-inactivated N1115 via modulation of the microbiota-gut-brain axis.

Antibiotic cocktail-induced gut microbiota depletion in different stages could cause host cognitive impairment and emotional disorders in adulthood in different manners.

Gut microbiota depletion may result in cognitive impairment and emotional disorder. This study aimed to determine the possible association between host gut microbiota, cognitive function, and emotion in various life stages and its related underlying mechanisms. Seventy-five neonatal mice were randomly divided into five groups (n = 15 per group). Mice in the vehicle group were administered distilled water from birth to death, and those in the last four groups were administered antibiotic cocktail from birth to death, from birth to postnatal day (PND) 21 (infancy), from PND 21 to 56 (adolescence), and from PND 57 to 84 (adulthood), respectively. Antibiotic exposure consistently altered the gut microbiota composition and decreased the diversity of gut microbiota. Proteobacteria were the predominant bacteria instead of Firmicutes and Bacteroidetes after antibiotic exposure in different life stages. Long-term and infant gut microbiota depletion resulted in anxiety- and depression-like behaviors, memory impairments, and increased expression of γ-aminobutyric acid type A receptor α1 of adult mice. Long-term antibiotic exposure also significantly decreased serum interleukin (IL)-1ß, IL-10, and corticosterone of adult mice. Gut microbiota depletion in adolescence resulted in anxiety-like behaviors, short-term memory decline, decreased serum interferon-γ (IFN-γ), mRNA expression of 5-hydroxytryptamine receptor 1A, and neuropeptide Y receptor Y2 in the prefrontal cortex of adult mice. Antibiotic exposure in adulthood damaged short-term memory and decreased serum IL-10, IFN-γ, and increased γ-aminobutyric acid type B receptor 1 mRNA expression of adult mice. These results suggest that antibiotic-induced gut microbiota depletion in the long term and infancy resulted in the most severe cognitive and emotional disorders followed by depletion in adolescence and adulthood. These results also suggest that gut microbes could influence host cognitive function and emotion in a life stage-dependent manner by affecting the function of the immune system, hypothalamic-pituitary-adrenal axis, and the expression of neurochemicals in the brain.

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

This study was conducted to evaluate the possibility of using heated-inactivated lactobacilli to protect neonates from harmful effects of antibiotics. Thirty neonate mice were randomly divided into three groups of ten and treated with either sterilized water, an antibiotics cocktail, or the same antibiotics plus heat-inactivated Lactobacillus paracasei N1115. The administration of antibiotics significantly increased the serum interleukin-6 (IL-6) levels of the tested mice (p<0.01, p<0.001, respectively) and decreased their serum corticosterone levels (p<0.01, p<0.01, respectively). The colonic crypts were significantly less deep in mice treated with antibiotics and with antibiotics plus N1115 (p<0.05). Antibiotics caused significantly abnormal expression of brain-derived neurotrophic factor (BDNF), γ-aminobutyric acid type A receptor α1 (GABAAα1), γ-aminobutyric acid type B receptor1 (GABAb1), and 5-hydroxytryptamine receptor1A (5-HT1A) in the hippocampus (p<0.05, p<0.01, p<0.01, respectively) and of GABAAα1 in the prefrontal cortex (p<0.01). Heat-inactivated lactobacilli alleviated these abnormal changes. Antibiotics greatly decreased the Shannon index of the fecal microbiota and significantly increased the number of Proteobacteria (p<0.001), with fewer Bacteroidetes and Firmicutes (p<0.05). Antibiotics not only cause microbiota dysbiosis, but also cause abnormal changes in important molecules in the gut-brain axis. All these abnormal changes are alleviated by heat-inactivated L. paracasei N1115. This indicates that heat-inactivated L. paracasei N1115 has a certain improvement effect on changes caused by antibiotics.

Loading ceftriaxone, vancomycin, and Bifidobacteria bifidum TMC3115 to neonatal mice could differently and consequently affect intestinal microbiota and immunity in adulthood.

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.

Bifidobacterium bifidum TMC3115 Can Characteristically Influence Glucose and Lipid Profile and Intestinal Microbiota in the Middle-Aged and Elderly.

Bifidobacterium bifidum TMC3115 strain (TMC3115) was orally administrated to 47 subjects with mild hyperglycaemia and dyslipidaemia aged 45 to 75 years for 3 weeks. Blood samples were collected before and after intervention for profiling plasma total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol and triglyceride concentrations, as well as fasting blood glucose. Before and 3 and 4 weeks after intervention, the faecal samples were collected to analyse faecal microbiota using the sequencing of 16S rRNA genes with a next-generation sequencer. TMC3115 significantly decreased plasma TC and LDL-C levels of the tested subjects after intervention (P < 0.05). The frequencies of defaecation and faecal odour after the intervention and 1 week later were significantly better than at pre-intervention, respectively. TMC3115 administration increased Firmicutes, Bacteroides and Actinobacteria and decreases in Proteobacteria and Fusobacteria. There were significant increases in the proportions of Dorea and Lachnospira after the intervention (P < 0.05). TMC3115 also increased the level of Firmicutes and decreased that of Bacteroidetes 1 week after the intervention (P < 0.05). Serum triglycerides correlated negatively with the proportions of Bacteroidetes (R = - 0.21, P = 0.047) and Bacteroides (R = - 0.23, P = 0.029), while the relative abundance of Dialister of Firmicutes correlated negatively and significantly with the serum LDL-C (R = - 0.24, P = 0.022) and TC levels (R = - 0.22, P = 0.030). These results indicate that TMC3115 might exhibit beneficial effects on the serum cholesterol metabolism of subjects with dyslipidaemia through modulation of their intestinal microbiota. Trial registration: ChiCTR-OOC-16010271.

[Effect of ceftriaxone on the intestinal epithelium and microbiota in neonatal mice].

OBJECTIVE: To investigate the effect of ceftriaxone on the intestinal epithelium and microbiota in mice in the early-life stage, as well as the recovery of the intestinal epithelium and reconstruction of intestinal microbiota in adult mice. METHODS: A total of 36 BALB/C neonatal mice were randomly divided into control group and experimental group, with 18 mice in each group. The mice in the experimental group were given ceftriaxone 100 mg/kg every day by gavage within 21 days after birth. Those in the control group were given an equal volume of normal saline by gavage. Immunohistochemistry was used to measure the expression of Ki67, Muc2, and ZO-1 in the intestinal epithelium. qPCR and next-generation sequencing were used to analyze the overall concentration and composition of fecal bacteria. RESULTS: After 21 days of ceftriaxone intervention, the experimental group had a significant reduction in body weight, a significant reduction in the expression of Ki67 and ZO-1 and a significant increase in the expression of Muc2 in intestinal epithelial cells, a significant reduction in the overall concentration of fecal bacteria, and a significant increase in the diversity of fecal bacteria compared with the control group (P<0.05). Firmicutes was the most common type of fecal bacteria in the experimental group, and there were large amounts of Staphylococcus and Enterococcus. The experimental group had a certain degree of recovery of the intestinal epithelium, but there were still significant differences in body weight and the structure of intestinal microbiota between the two groups at 56 days after birth (P<0.05). CONCLUSIONS: Early ceftriaxone intervention significantly affects the development of the intestinal epithelium and the construction of intestinal microbiota in the early-life stage. The injury of the intestinal microbiota in the early-life stage may continue to the adult stage and affect growth and development and physiological metabolism.

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

BACKGROUND: The 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. RESULTS: Among 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. CONCLUSIONS: These 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.

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

PURPOSE: To 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 METHODS: Two 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. RESULTS: Compared 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). CONCLUSION: The 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.

Assessing genome-wide copy number variation in the Han Chinese population.

BACKGROUND: Copy number variation (CNV) is a valuable source of genetic diversity in the human genome and a well-recognised cause of various genetic diseases. However, CNVs have been considerably under-represented in population-based studies, particularly the Han Chinese which is the largest ethnic group in the world. OBJECTIVES: To build a representative CNV map for the Han Chinese population. METHODS: We conducted a genome-wide CNV study involving 451 male Han Chinese samples from 11 geographical regions encompassing 28 dialect groups, representing a less-biased panel compared with the currently available data. We detected CNVs by using 4.2M NimbleGen comparative genomic hybridisation array and whole-genome deep sequencing of 51 samples to optimise the filtering conditions in CNV discovery. RESULTS: A comprehensive Han Chinese CNV map was built based on a set of high-quality variants (positive predictive value >0.8, with sizes ranging from 369 bp to 4.16 Mb and a median of 5907 bp). The map consists of 4012 CNV regions (CNVRs), and more than half are novel to the 30 East Asian CNV Project and the 1000 Genomes Project Phase 3. We further identified 81 CNVRs specific to regional groups, which was indicative of the subpopulation structure within the Han Chinese population. CONCLUSIONS: 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.