Cyanopeptides Restriction and Degradation Co-mediate Microbiota Assembly During a Freshwater Cyanobacterial Harmful Algal Bloom (CyanoHAB)

Cyanobacterial harmful algal blooms (CyanoHABs) are globally intensifying and exacerbated by climate change and eutrophication. However, microbiota assembly mechanisms underlying CyanoHABs remain scenario specific and elusive. Especially, cyanopeptides, as a group of bioactive secondary metabolites of cyanobacteria, could affect microbiota assembly and ecosystem function. Here, the trajectory of cyanopeptides were followed and linked to microbiota during Microcystis-dominated CyanoHABs in lake Taihu, China. The most abundant cyanopeptide classes detected included microginin, spumigin, microcystin, nodularin and cyanopeptolin with total MC-LR-equivalent concentrations between 0.23 and 2051.54 ppb, of which cyanotoxins beyond microcystins (e.g., cyanostatin B and nodularin_R etc.) far exceeded reported organismal IC50 and negatively correlated with microbiota diversity, exerting potential collective eco-toxicities stronger than microcystins alone. The microbial communities were differentiated by size fraction and sampling date throughout CyanoHABs, and surprisingly, their variances were better explained by cyanopeptides (19-38%) than nutrients (0-16%). Cyanopeptides restriction (e.g., inhibition) and degradation are first quantitatively verified as the deterministic drivers governing community assembly, with stochastic processes being mediated by interplay between cyanopeptide dynamics and lake microbiota. This study presents an emerging paradigm in which cyanopeptides restriction and degradation co-mediate lake water microbiota assembly, unveiling new insights about the ecotoxicological significance of CyanoHABs to freshwater ecosystems.

Analysis of Gut Microbiota in Patients with Coronary Artery Disease and Hypertension

Cardiovascular and cerebrovascular diseases are characterized by high rates of morbidity and mortality. Microbiota is closely associated with cardiovascular disease. We aimed to comprehensively analyze the microbiotas of 300 healthy controls, 300 patients with high blood pressure (HBP), and 300 patients with coronary heart disease (CHD). The results indicated no significant difference in microbiota diversity among the three groups ( P > 0.05 ). However, differences in microbiota richness among the three groups were significant ( P < 0.05 ). Bacteroidetes and Bacteroidia were the dominant bacteria in the CHD group, Enterobacteriales and Escherichia-shigella in the HBP group, and Acidaminococcaceae and Phascolarctobacterium in the healthy control group. The prediction results of the random forest model indicated that the population with CHD displayed prominent features with high sensitivity, indicating that microbiota detection might become a novel clinical indicator to predict and monitor the risk of cardiovascular events. The prediction of microbiota function suggested differences in oxygen supply and chronic inflammation between populations with HBP/CHD and healthy populations. Although there is no difference in gut microbiota diversity among the three groups, each group has its dominant microbiota in terms of richness.

Jasmine Tea Attenuates Chronic Unpredictable Mild Stress-Induced Depressive-like Behavior in Rats via the Gut-Brain Axis

The number of depressed people has increased worldwide. Dysfunction of the gut microbiota has been closely related to depression. The mechanism by which jasmine tea ameliorates depression via the brain-gut-microbiome (BGM) axis remains unclear. Here, the effects of jasmine tea on rats with depressive-like symptoms via the gut microbiome were investigated. We first established a chronic unpredictable mild stress (CUMS) rat model to induce depressive symptoms and measured the changes in depression-related indicators. Simultaneously, the changes in gut microbiota were investigated by 16S rRNA sequencing. Jasmine tea treatment improved depressive-like behaviors and neurotransmitters in CUMS rats. Jasmine tea increased the gut microbiota diversity and richness of depressed rats induced by CUMS. Spearman’s analysis showed correlations between the differential microbiota (Patescibacteria, Firmicutes, Bacteroidetes, Spirochaetes, Elusimicrobia, and Proteobacteria) and depressive-related indicators (BDNF, GLP-1, and 5-HT in the hippocampus and cerebral cortex). Combined with the correlation analysis of gut microbiota, the result indicated that jasmine tea could attenuate depression in rats via the brain- gut-microbiome axis.

Effects of Sleep Deprivation on Weight Loss and Gut Microbiota Diversity in Obese Patients on a Calorie Restrict Diet

Objective: This study aimed to investigate the effects of sleep deprivation (SD) on the weight loss and gut microbiota diversity in obese patients on a calorie restrict diet (CRD). Methods: Twenty obese patients who were divided into two groups: sleep deprivation group(SD group,n=10) and non-sleep deprivation group(NSD group ,n=10). All the patients received CRD for twelve weeks. Measurement of anthropometric parameters, biochemical examinations and gut microbiota detection were done at baseline and the end of week 12. MI Bands were used to monitor the sleep and exercise. Body shape parameters were measured by using the JAWON ioi353. The gut microbiota was examined by PCR in the v3-v5 region of 16S rDNA gene, and high-throughput sequencing was carried out on the Illumina Miseq platform. The operational taxonomic units (OTUs) was used for analysis. Results: 1. CRD improved the body weight (BW) , waist circumference(WC), blood pressure (BP),basal metabolic rate (BMR) ,body fat content(BFC),and Insulin resistance index (HOMA-IR) in all obese patients. 2. In the NSD group, the BW, BFC, VFA, BMR and total cholesterol (TC) reduced significantly when compared with the NSD group after CRD intervention (P<0.05). 3. The Alpha diversity of gut microbiota remained unchanged after the intervention in two groups after CRD intervention. 4. There was a negative correlation between Mollicutes and BMR in the NSD group. Conclusion: The effects of CRD may be weaken by SD in weight loss and the metabolism of blood lipid. Mollicutes bacteria may be related to the weight loss after CRD intervention in obese patients.

Life History Traits in Two Drosophila Species Differently Affected by Microbiota Diversity under Lead Exposure

Life history traits determine the persistence and reproduction of each species. Factors that can affect life history traits are numerous and can be of different origin. We investigated the influence of population origin and heavy metal exposure on microbiota diversity and two life history traits, egg-to-adult viability and developmental time, in Drosophila melanogaster and Drosophila subobscura, grown in the laboratory on a lead (II) acetate-saturated substrate. We used 24 samples, 8 larval and 16 adult samples (two species × two substrates × two populations × two sexes). The composition of microbiota was determined by sequencing (NGS) of the V3–V4 variable regions of the 16S rRNA gene. The population origin showed a significant influence on life history traits, though each trait in the two species was affected differentially. Reduced viability in D. melanogaster could be a cost of fast development, decrease in Lactobacillus abundance and the presence of Wolbachia. The heavy metal exposure in D. subobscura caused shifts in developmental time but maintained the egg-to-adult viability at a similar level. Microbiota diversity indicated that the Komagataeibacter could be a valuable member of D. subobscura microbiota in overcoming the environmental stress. Research on the impact of microbiota on the adaptive response to heavy metals and consequently the potential tradeoffs among different life history traits is of great importance in evolutionary research.

Non-pest household arthropods as a reservoir of human opportunistic pathogens

Arthropods are recognised as potential mechanical and biological vectors for infectious diseases in outdoor environments. However, a comprehensive understanding of the indoor arthropod community diversity and of the role that their associated microbiota may have as disease vectors is largely unexplored. Here, we study the arthropod community and the associated microbiota diversity of twenty indoor environments, sampled over a period of twelve months from urban and suburban households by citizen scientists in the West Midlands (UK). We compare the arthropods diversity between environments and over the sampling months. We characterize the exogenous (exoskeleton) and endogenous (gut) bacterial communities associated with all specimens of arthropods actively captured using both a traditional culture-based and an unbiased metabarcoding approach. For the first time, we describe the exogenous and endogenous microbiota composition and diversity of 14 arthropod families found in indoor environments. We find that both the exogenous and the endogenous microbiota are potential carriers of human opportunistic pathogens, with potential implications for public health. We discover that many bacteria families are shared across the exogenous microbiota of arthropods, likely influenced by the bacteria present in the environment. Conversely, the endogenous microbiota composition is unique to the arthropod families, and likely genetically determined. We show that the metabarcoding unbiased approach is a superior tool to characterize the microbiota associated with each arthropod family. This study provides new insights into bacterial carriage in household arthropods as potential reservoirs of infectious disease.

Impact of maternal antibodies and microbiota development on the immunogenicity of oral rotavirus vaccine in African, Indian, and European infants

Identifying risk factors for impaired oral rotavirus vaccine (ORV) efficacy in low-income countries may lead to improvements in vaccine design and delivery. In this prospective cohort study, we measure maternal rotavirus antibodies, environmental enteric dysfunction (EED), and bacterial gut microbiota development among infants receiving two doses of Rotarix in India (n = 307), Malawi (n = 119), and the UK (n = 60), using standardised methods across cohorts. We observe ORV shedding and seroconversion rates to be significantly lower in Malawi and India than the UK. Maternal rotavirus-specific antibodies in serum and breastmilk are negatively correlated with ORV response in India and Malawi, mediated partly by a reduction in ORV shedding. In the UK, ORV shedding is not inhibited despite comparable maternal antibody levels to the other cohorts. In both India and Malawi, increased microbiota diversity is negatively correlated with ORV immunogenicity, suggesting that high early-life microbial exposure may contribute to impaired vaccine efficacy.

Redefining intestinal immunity with single-cell transcriptomics

The intestinal immune system represents the largest collection of immune cells in the body and is continually exposed to antigens from food and the microbiota. Here we discuss the contribution of single-cell transcriptomics in shaping our understanding of this complex system. We consider the impact on resolving early intestine development, engagement with the neighbouring microbiota, diversity of intestinal immune cells, compartmentalisation within the intestines and interactions with non-immune cells. Finally, we offer a perspective on open questions about gut immunity that evolving single-cell technologies are well placed to address.