Editorial: Nutritional modulation of central nervous system development, maintenance, plasticity, and recovery

No abstrac

Gut microbiome–micronutrient interaction: The key to controlling the bioavailability of minerals and vitamins?

Micronutrients, namely, vitamins and minerals, are necessary for the proper functioning of the human body, and their deficiencies can have dramatic short- and long-term health consequences. Among the underlying causes, certainly a reduced dietary intake and/or poor absorption in the gastrointestinal tract play a key role in decreasing their bioavailability. Recent evidence from clinical and in vivo studies suggests an increasingly important contribution from the gut microbiome. Commensal microorganisms can in fact regulate the levels of micronutrients, both by intervening in the biosynthetic processes and by modulating their absorption. This short narrative review addresses the pivotal role of the gut microbiome in influencing the bioavailability of vitamins (such as A, B, C, D, E, and K) and minerals (calcium, iron, zinc, magnesium, and phosphorous), as well as the impact of these micronutrients on microbiome composition and functionality. Personalized microbiome-based intervention strategies could therefore constitute an innovative tool to counteract micronutrient deficiencies by modulating the gut microbiome toward an eubiotic configuration capable of satisfying the needs of our organism, while promoting general health

The human microbiomes in pancreatic cancer: Towards evidence-based manipulation strategies?

Recent pieces of evidence have emerged on the relevance of microorganisms in modulating responses to anticancer treatments and reshaping the tumor-immune microenvironment. On the one hand, many studies have addressed the role of the gut microbiota, providing interesting correlative findings with respect to etiopathogenesis and treatment responses. On the other hand, intra-tumoral bacteria are being recognized as intrinsic and essential components of the cancer microenvironment, able to promote a plethora of tumor-related aspects from cancer growth to resistance to chemotherapy. These elements will be probably more and more valuable in the coming years in early diagnosis and risk stratification. Furthermore, microbial-targeted intervention strategies may be used as adjuvants to current therapies to improve therapeutic responses and overall survival. This review focuses on new insights and therapeutic approaches that are dawning against pancreatic cancer: a neoplasm that arises in a central metabolic “hub” interfaced between the gut and the host

Envisioning emerging frontiers on human gut microbiota and its applications

The human gut microbiota is involved in multiple health-influencing host interactions during the host’s entire life span. Microbes colonize the infant gut instantaneously after birth and subsequently the founding and interactive progress of this early gut microbiota is considered to be driven and modulated by different host- and microbe-associated forces. A rising number of studies propose that the composition of the human gut microbiota in the early stages of life impact on the human health conditions at later stages of life. This notion has powered research aimed at detailed investigations of the infant gut microbiota composition. Nevertheless, the molecular mechanisms supporting the gut microbiome functionality and the interaction of the early gut microbes with the human host remain largely unknown

Microbiota and Cancer: The Emerging Beneficial Role of Bifidobacteria in Cancer Immunotherapy

Many intestinal bacteria are believed to be involved in various inflammatory and immune processes that influence tumor etiology because of their metabolic properties and their ability to alter the microbiota homeostasis. Although many functions of the microbiota are still unclear, there is compelling experimental evidence showing that the intestinal microbiota is able to modulate carcinogenesis and the response to anticancer therapies, both in the intestinal tract and other body sites. Among the wide variety of gut-colonizing microorganisms, various species belonging to the Bifidobacterium genus are believed to elicit beneficial effects on human physiology and on the host-immune system. Recent findings, based on preclinical mouse models and on human clinical trials, have demonstrated the impact of gut commensals including bifidobacteria on the efficacy of tumor-targeting immunotherapy. Although the underlying molecular mechanisms remain obscure, bifidobacteria and other microorganisms have become a promising aid to immunotherapeutic procedures that are currently applied to treat cancer. The present review focuses on strategies to recruit the microbiome in order to enhance anticancer responses and develop therapies aimed at fighting the onset and progression of malignancies

Special issue ‘bifidobacteria: Insights from ecology to genomics of a key microbial group of the mammalian gut microbiota’

In recent years, substantial efforts have been made to dissect the composition of microbial communities that are present in the human gut, and to investigate their interactions with their host [...]

Exploring the ecology of bifidobacteria and their genetic adaptation to the mammalian gut

The mammalian gut is densely inhabited by microorganisms that have coevolved with their host. Amongst these latter microorganisms, bifidobacteria represent a key model to study host–microbe interaction within the mammalian gut. Remarkably, bifidobacteria naturally occur in a range of ecological niches that are either directly or indirectly connected to the animal gastrointestinal tract. They constitute one of the dominant bacterial members of the intestinal microbiota and are among the first colonizers of the mammalian gut. Notably, the presence of bifidobacteria in the gut has been associated with several health-promoting activities. In this review, we aim to provide an overview of current knowledge on the genetic diversity and ecology of bifidobacteria. Furthermore, we will discuss how this important group of gut bacteria is able to colonize and survive in the mammalian gut, so as to facilitate host interactions

Assessing the Genomic Variability of Gardnerella vaginalis through Comparative Genomic Analyses: Evolutionary and Ecological Implications

Gardnerella vaginalis is described as a common anaerobic vaginal bacterium whose presence may correlate with vaginal dysbiotic conditions. In the current study, we performed phylogenomic analyses of 72 G. vaginalis genome sequences, revealing noteworthy genome differences underlying a polyphyletic organization of this taxon. Particularly, the genomic survey revealed that this species may actually include nine distinct genotypes (GGtype1 to GGtype9). Furthermore, the observed link between sialidase and phylogenomic grouping provided clues of a connection between virulence potential and the evolutionary history of this microbial taxon. Specifically, based on the outcomes of these in silico analyses, GGtype3, GGtype7, GGtype8, and GGtype9 appear to have virulence potential since they exhibited the sialidase gene in their genomes. Notably, the analysis of 34 publicly available vaginal metagenomic samples allowed us to trace the distribution of the nine G. vaginalis genotypes identified in this study among the human population, highlighting how differences in genetic makeup could be related to specific ecological properties. Furthermore, comparative genomic analyses provided details about the G. vaginalis pan- and core genome contents, including putative genetic elements involved in the adaptation to the ecological niche as well as many putative virulence factors. Among these putative virulence factors, particularly noteworthy genes identified were the gene encoding cholesterol dependent cytolysin (CDC) toxin vaginolysin and genes related to microbial biofilm formation, iron uptake, adhesion to the vaginal epithelium, as well as macrolide antibiotic resistance. IMPORTANCE The identification of nine different genotypes among members of G. vaginalis allowed us to distinguish an uneven distribution of virulence-associated genetic traits within this taxon and thus suggest the potential occurrence of putative pathogen and commensal G. vaginalis strains. These findings, coupled with metagenomics microbial profiling of human vaginal microbiota, permitted us to get insights into the distribution of the genotypes among the human population, highlighting the presence of different structural communities in terms of G. vaginalis genotypes

Gut Microbiota Dysbiosis in Childhood Vasculitis: A Perspective Comparative Pilot Study

Kawasaki disease (KD) and Henoch–Schönlein purpura (HSP) are the most frequent vasculitis in childhood. For both, a multifactorial mechanism has been hypothesised, with an abnormal immune response in genetically predisposed children. Gut microbiota (GM) alterations might trigger the hyperimmune reaction. Our aim was to explore the GM in KD and compare it with the GM of HSP and febrile children. Children diagnosed with KD, HSP and non-KD febrile illness (F) were enrolled. GM was profiled by 16S rRNA gene sequencing and compared with the profiles of healthy children from previous studies. We enrolled 13 KD, 10 HSP and 12 F children. Their GM significantly differed from controls, with an overall reduction in the relative abundance of beneficial taxa belonging to the Ruminococcaceae and Lachnospiraceae families. Potential KD and HSP signatures were identified, including smaller amounts of Dialister in the former, and Clostridium and Akkermansia in the latter. Notably, the GM structures of KD, HSP and F patients stratified by abdominal involvement, with more severe dysbiosis in those suffering from intestinal symptoms. This is the first study analysing GM in a mostly Caucasian cohort of KD and HSP children. Our data could open up new opportunities for childhood vasculitis treatment

Multi-population cohort meta-analysis of human intestinal microbiota in early life reveals the existence of infant community state types (ICSTs)

Appropriate development of the intestinal microbiota during infancy is known to be important for human health. In fact, aberrant alterations of the microbial composition during childhood may cause short- and/or long-term negative health effects. Many factors influence the initial assembly and subsequent progression of the gut microbiota of a neonate, such as feeding type, delivery mode, gestational age, maternal metabolic status and antibiotic exposure. In the current study, the composition of the infant gut core-microbiota was explored, revealing particular variations of this core-microbiota during the first three years as influenced by delivery mode and feeding type. A multi-population cohort meta-analysis was performed by selecting 15 publicly available datasets pertaining to taxonomic profiles of 1035 fecal samples of healthy infants, as obtained by means of a 16S rRNA gene-based profiling approach. Interestingly, this multi-population cohort meta-analysis revealed great microbial complexity and specific taxonomic shifts in children older than six months, suggesting a major impact by the introduction of solid foods which prompts progression of infant gut microbiota towards that typical of adults. The taxonomic data sets employed in this multi-population cohort meta-analysis possess the statistical robustness to allow the identification of infant community state types (ICSTs). Our analysis therefore reveals the existence of specific taxonomic patterns that correspond to particular nutritional and developmental stages of early life, and that had previously been obscured by the high variability typical of such infant gut microbiota