Gut microbiome alterations in patients with wheat-dependent exercise-induced anaphylaxis

The intestinal microbiota plays a critical role in food allergy development. However, little is known regarding the structure and composition of the intestinal microbiota in patients with wheat-dependent exercise-induced anaphylaxis (WDEIA). We examined the gut microbiota alterations in patients with WDEIA and the microbiota’s association with WDEIA. Fecal samples were collected from 25 patients with WDEIA and 25 healthy controls. Environmental exposure factors were obtained, serum total IgE, IgE specific to wheat, gluten, and ω-5 gliadin were measured. Fecal samples were profiled using 16S rRNA gene sequencing. The relative abundances of the bacterial genera Blautia (P < 0.05), Erysipelatoclostridium (P < 0.01), Akkermansia (P < 0.05) and Lachnospiraceae_NK4A136_group (P < 0.05) were significantly increased, while those of Lactobacillus (P = 0.001) and Dialister (P < 0.05) were significantly decreased in subjects with WDEIA. The microbial diversity did not differ between WDEIA patients and healthy controls. IgE specific to ω-5 gliadin was positively associated with the Oscillospira (r = 0.48, P < 0.05) and negatively associated with Leuconostoc (r = −0.49, P < 0.05). Total IgE levels were significantly negatively correlated with Bifidobacterium (P < 0.05). The gut microbiome compositions in WDEIA patients differed from those of healthy controls. We identified a potential association between the gut microbiome and WDEIA development. Our findings may suggest new methods for preventing and treating WDEIA.     

Profiling of the microbiota in the remaining sports drink and orange juice in plastic bottles after direct drinking

ObjectivesThe survival of bacteria in the sports drink and orange juice remaining in and at the mouth of bottles after direct drinking was examined after immediately drinking and incubation at 37 °C for 24 h.MethodsNine healthy participants were asked to drink approximately 100 mL of a plastic bottled sports drink or orange juice. The samples were cultured anaerobically at 37 °C for 7 days. Genomic DNA was extracted from the resulting individual colonies, and bacterial species were identified using 16 S rRNA gene sequencing.ResultsThe mean amount of bacteria in the remaining sports drink and orange juice, immediately after drinking, were (1.6 ± 2.3) × 10³ colony-forming units (CFU)/mL and (2.9 ± 3.3) × 10³ CFU/mL, respectively. Additionally, bacteria recovered from the mouths of the sports drink and orange juice bottles were (2.5 ± 5.5) × 10⁴ CFU/mL and (5.8 ± 2.4) × 10³ CFU/mL, respectively. Oral bacteria, such as Streptococcus, Actinomyces, Neisseria, and Rothia were found to be transferred in the sports drink and orange juice, and the bacteria were scarcely detected after incubation at 37 °C for 24 h.ConclusionsThe bacterial levels differed significantly from the previously reported levels in bottled tea 24 h after drinking, suggesting that remaining drinks with low pH levels can be preserved for a longer period.     

Inflammatory pathways in Alzheimer’s disease mediated by gut microbiota

In the past decade, numerous studies have demonstrated the close relationship between gut microbiota and the occurrence and development of Alzheimer’s disease (AD). However, the specific mechanism is still unclear. Both the neuroinflammation and systemic inflammation serve as the key hubs to accelerate the process of AD by promoting pathology and damaging neuron. What's more, the gut microbiota is also crucial for the regulation of inflammation. Therefore, this review focused on the role of gut microbiota in AD through inflammatory pathways. Firstly, this review summarized the relationship and interaction among gut microbiota, inflammation, and AD. Secondly, the direct and indirect regulatory effects of gut microbiota on AD through inflammatory pathways were described. These effects were mainly mediated by the component of the gut microbiota (lipopolysaccharides (LPS) and amyloid peptides), the metabolites of bacteria (short-chain fatty acids, branched amino acids, and neurotransmitters) and functional by-products (bile acids). In addition, potential treatments (fecal microbiota transplantation, antibiotics, probiotics, prebiotics, and dietary interventions) for AD were also discussed through these mechanisms. Finally, according to the current research status, the key problems to be solved in the future studies were proposed.     

The fecal microbiome and rotavirus vaccine immunogenicity in rural Zimbabwean infants

BackgroundOral rotavirus vaccine (RVV) immunogenicity is considerably lower in low- versus high-income populations; however, the mechanisms underlying this remain unclear. Previous evidence suggests that the gut microbiota may contribute to differences in oral vaccine efficacy.MethodsWe performed whole metagenome shotgun sequencing on stool samples and measured anti-rotavirus immunoglobulin A in plasma samples from a subset of infants enrolled in a cluster randomized 2 × 2 factorial trial of improved water, sanitation and hygiene and infant feeding in rural Zimbabwe (SHINE trial: NCT01824940). We examined taxonomic microbiome composition and functional metagenome features using random forest models, differential abundance testing and regression analyses to explored associations with RVV immunogenicity.ResultsAmong 158 infants with stool samples and anti-rotavirus IgA titres, 34 were RVV seroconverters. The median age at stool collection was 43 days (IQR: 35–68), corresponding to a median of 4 days before the first RVV dose. The infant microbiome was dominated by Bifidobacterium longum. The gut microbiome differed significantly between early (≤42 days) and later samples (>42 days) however, we observed no meaningful differences in alpha diversity, beta diversity, species composition or functional metagenomic features by RVV seroconversion status. Bacteroides thetaiotaomicron was the only species associated with anti-rotavirus IgA titre. Random forest models poorly classified seroconversion status by both composition and functional microbiome variables.ConclusionsRVV immunogenicity is low in this rural Zimbabwean setting, however it was not associated with the composition or function of the early-life gut microbiome in this study. Further research is warranted to examine the mechanisms of poor oral RVV efficacy in low-income countries.     

Gut microbiota composition in patients with newly diagnosed bipolar disorder and their unaffected first-degree relatives

ObjectiveAn aberrant gut microbiota may be associated with a broad spectrum of diseases including mental illness. The gut microbiota is scarcely studied in bipolar disorder (BD). We examined the gut microbiota composition in patients with newly diagnosed BD, their unaffected first-degree relatives and healthy individuals.MethodsStool samples were collected from 113 patients with BD, 39 unaffected first-degree relatives and 77 healthy individuals and the microbiota was profiled using 16S rRNA gene amplicon sequencing.ResultsThe gut microbiota community membership of patients with BD differed from that of healthy individuals (R² = 1.0%, P = 0.008), whereas the community membership of unaffected first-degree relatives did not. Flavonifractor was present in 61% of patients with BD, 42% of their unaffected relatives and 39% of healthy individuals. Presence of Flavonifractor was associated with an odds ratio of 2.9 (95%CI: 1.6–5.2, P = 5.8 × 10⁻⁴, Q = 0.036) for having BD. When excluding smokers, presence of Flavonifractor was associated with an odds ratio of 2.3 (95%CI: 1.1–5.3, P = 0.019) for having BD. However, when considering the subsample of non-smokers only, BD and presence of Flavonifractor were no longer associated when adjusted for all possible tests at genus level (Q = 0.6). Presence of Flavonifractor in patients with BD was associated with smoking and female sex, but not with age, waist circumference, exercise level, high-sensitive C-reactive protein, current affective state, subtype of BD, illness duration or psychotropic medication, respectively.ConclusionFlavonifractor, a bacterial genus that may induce oxidative stress and inflammation in its host, was associated with BD. Higher prevalence of smoking among patients with BD contributed to our findings, and it cannot be excluded that findings are influenced by residual confounding.     

Alopecia y microbioma: ¿futura diana terapéutica?

The human microbiome includes viruses, bacteria, and fungi. There is evidence that in addition to microbiome variation in different areas of the body or according to ethnicity and sex, the microbiome specific to the scalp is conditioned by such factors as humidity, protection from UV light, and pH. Although little information has yet been published about the microbiome of hair follicles and its role in the pathogenesis of diseases, interest in this area of research is emerging. Studies have shown that components of the follicular microbiome influence such disorders as androgenetic alopecia and alopecia areata. A current hypothesis is that interventions that target the microbiome may lead to innovative therapies for many diseases.     

铁、宿主和肠道菌群相互作用的研究进展

目的 研究铁、宿主和肠道菌群之间的相互关系及其对肠道健康的影响。方法 检索中国知网、PubMed、EMBASE、Web of Science等数据库，查找铁和肠道菌群的相关文献，并进行整理归纳与总结。结果 铁对于维持宿主健康和肠道微生物生长定植具有重要作用，同时肠道微生物也影响着宿主铁的吸收利用。在一些病理条件下，肠道内未被吸收的铁可与微生物及其代谢物相互作用对宿主形成一种致病关系。结论 避免缺铁和铁过量引起的肠道菌群失调及其可能导致的宿主健康损害和疾病风险，并制订特殊生理状态和疾病状态下补充铁的策略，是目前医务工作者需要重新思考的问题。     

Le transfert de microbiote fécal : quel potentiel thérapeutique dans le traitement des maladies métaboliques ?

An imbalance of the gut microbiota composition or functions is frequently observed during obesity and metabolic diseases. Studies on rodents showed that the modulation of microbiota dysbiosis by various methods is associated with an improvement in metabolic parameters. In humans, dietary interventions or bariatric surgery are accompanied by changes in the composition of the microbiota. Fecal microbiota transfer is a promising therapeutic approach to change the composition of the gut microbiota, however, it is currently only officially indicated in the treatment of recurrent Clostridioides difficile colitis. Literature documenting the effect of faecal microbiota transplantation in metabolic diseases is much less abundant. Nevertheless, FMT from healthy donors to obese patients with metabolic syndrome significantly improves the insulin sensitivity of the recipients despite the large response variability. This variability seems to be mainly related to the difference in richness between the donor's microbiota and the recipient's microbiota. To date, the impact of the donor's choice, the protocol of preparation, storage and administration of the inoculum, as well as the possible preparation of the recipient are to be explored.