Dietary amino acids, macronutrients, vaginal birth, and breastfeeding are associated with the vaginal microbiome in early pregnancy.

Unlabelled: The vaginal microbiome is a key player in the etiology of spontaneous preterm birth. This study aimed to illustrate maternal environmental factors associated with vaginal microbiota composition and function in pregnancy. Women in healthy pregnancy had vaginal microbial sampling from the posterior vaginal fornix performed at 16 weeks gestation.

Profiling of vaginal isolated from preterm and full-term pregnancies reveals strain-specific factors relating to host interaction.

Each year, 15 million infants are born preterm (<37 weeks gestation), representing the leading cause of mortality for children under the age of five. Whilst there is no single cause, factors such as maternal genetics, environmental interactions, and the vaginal microbiome have been associated with an increased risk of preterm birth. Previous studies show that a vaginal microbiota dominated by is, in contrast to communities containing a mixture of genera, associated with full-term birth.

Detailed mapping of Bifidobacterium strain transmission from mother to infant via a dual culture-based and metagenomic approach.

A significant proportion of the infant gut microbiome is considered to be acquired from the mother during and after birth. Thus begins a lifelong and dynamic relationship with microbes that has an enduring impact on host health. Based on a cohort of 135 mother-infant (F = 72, M = 63) dyads (MicrobeMom: ISRCTN53023014), we investigated the phenomenon of microbial strain transfer, with a particular emphasis on the use of a combined metagenomic-culture-based approach to determine the frequency of strain transfer involving members of the genus Bifidobacterium, including species/strains present at low relative abundance.

Ability of Bifidobacterium breve 702258 to transfer from mother to infant: the MicrobeMom randomized controlled trial.

Background: The composition of the infant microbiome can have a variety of short- and long-term implications for health. It is unclear if maternal probiotic supplementation in pregnancy can affect the infant gut microbiome.

Objective: This study aimed to investigate if maternal supplementation of a formulation of Bifidobacterium breve 702258 from early pregnancy until 3 months postpartum could transfer to the infant gut.

Effect of a bacteriocin-producing on the pathogen in a model of the human distal colon.

The gut microbiome is a vast reservoir of microbes, some of which produce antimicrobial peptides called bacteriocins that may inhibit specific bacteria associated with disease. is an emerging human bacterial pathogen associated with gastrointestinal diseases including colorectal cancer (CRC). In this study, fecal samples of healthy donors were screened for potential bacteriocin-producing probiotics with antimicrobial activity against .

In Vitro and In Silico Based Approaches to Identify Potential Novel Bacteriocins from the Athlete Gut Microbiome of an Elite Athlete Cohort.

Exercise reduces inflammation, fatigue, and aids overall health. Additionally, physical fitness has been associated with desirable changes in the community composition of the athlete gut microbiome, with health-associated taxa being shown to be increased in active individuals. Here, using a combination of in silico and in vitro methods, we investigate the antimicrobial activity of the athlete gut microbiome.

An oxidation resistant pediocin PA-1 derivative and penocin A display effective anti- activity in a model human gut environment.

Pediocin PA-1 is a class IIa bacteriocin that is particularly effective against the foodborne pathogen . The loss of activity of PA-1 pediocin due to methionine oxidation is one of the challenges that limit the wider application of the bacteriocin. In this study, we heterologously expressed an oxidation resistant form of pediocin PA-1, i.

Shotgun sequencing of the vaginal microbiome reveals both a species and functional potential signature of preterm birth.

An association between the vaginal microbiota and preterm birth (PTB) has been reported in several research studies. Population shifts from high proportions of lactobacilli to mixed species communities, as seen with bacterial vaginosis, have been linked to a twofold increased risk of PTB. Despite the increasing number of studies using next-generation sequencing technologies, primarily involving 16S rRNA-based approaches, to investigate the vaginal microbiota during pregnancy, no distinct microbial signature has been associated with PTB.

Whey protein effects on energy balance link the intestinal mechanisms of energy absorption with adiposity and hypothalamic neuropeptide gene expression.

We tested the hypothesis that dietary whey protein isolate (WPI) affects the intestinal mechanisms related to energy absorption and that the resulting energy deficit is compensated by changes in energy balance to support growth. C57BL/6 mice were provided a diet enriched with WPI with varied sucrose content, and the impact on energy balance-related parameters was investigated. As part of a high-sucrose diet, WPI reduced the hypothalamic expression of pro-opiomelanocortin gene expression and increased energy intake.

The bacteriocin bactofencin A subtly modulates gut microbial populations.

The diverse and dynamic microbiota of the gastrointestinal tract represents a vast source of bioactive substances. These include bacteriocins, which are antimicrobial peptides with the potential to modulate gut populations to impact positively on human health. Although several gut-derived bacteriocins have been isolated, there remain only a few exceptional studies in which their influence on microbial populations within the gut has been investigated.

Homologues and bioengineered derivatives of LtnJ vary in ability to form D-alanine in the lantibiotic lacticin 3147.

Ltnα and Ltnβ are individual components of the two-peptide lantibiotic lacticin 3147 and are unusual in that, although ribosomally synthesized, they contain d-amino acids. These result from the dehydration of l-serine to dehydroalanine by LtnM and subsequent stereospecific hydrogenation to d-alanine by LtnJ. Homologues of LtnJ are rare but have been identified in silico in Staphylococcus aureus C55 (SacJ), Pediococcus pentosaceus FBB61 (PenN), and Nostoc punctiforme PCC73102 (NpnJ, previously called NpunJ [P.

Manipulation of charged residues within the two-peptide lantibiotic lacticin 3147.

Lantibiotics are antimicrobial peptides which contain a high percentage of post-translationally modified residues. While most attention has been paid to the role of these critical structural features, evidence continues to emerge that charged amino acids also play a key role in these peptides. Here 16 'charge' mutants of the two-peptide lantibiotic lacticin 3147 [composed of Ltnα (2+, 2-) and Ltnβ (2+)] were constructed which, when supplemented with previously generated peptides, results in a total bank of 23 derivatives altered in one or more charged residues.

Listeriolysin S, a novel peptide haemolysin associated with a subset of lineage I Listeria monocytogenes.

Streptolysin S (SLS) is a bacteriocin-like haemolytic and cytotoxic virulence factor that plays a key role in the virulence of Group A Streptococcus (GAS), the causative agent of pharyngitis, impetigo, necrotizing fasciitis and streptococcal toxic shock syndrome. Although it has long been thought that SLS and related peptides are produced by GAS and related streptococci only, there is evidence to suggest that a number of the most notorious Gram-positive pathogenic bacteria, including Listeria monocytogenes, Clostridium botulinum and Staphylococcus aureus, produce related peptides. The distribution of the L.

Two-peptide lantibiotics: a medical perspective.

Lantibiotics are ribosomally synthesised, post-translationally modified antimicrobial peptides that exhibit activity against a wide-range of Gram positive bacteria. During the last decade a number of two-peptide lantibiotics, i.e.

Insertional mutagenesis to generate lantibiotic resistance in Lactococcus lactis.

While the potential emergence of food spoilage and pathogenic bacteria with resistance to lantibiotics is a concern, the creation of derivatives of starter cultures and adjuncts that can grow in the presence of these antimicrobials may have applications in food fermentations. Here a bank of Lactococcus lactis IL1403 mutants was created and screened, and a number of novel genetic loci involved in lantibiotic resistance were identified.

Identification of a novel two-peptide lantibiotic, haloduracin, produced by the alkaliphile Bacillus halodurans C-125.

Complete genome sequencing of the alkaliphilic bacterium Bacillus halodurans C-125 revealed the presence of several genes homologous to those involved in the production of lantibiotic peptides. Additional bioinformatic analysis identified a total of eleven genes, spanning a 15 kbp region, potentially involved in the production, modification, immunity and transport of a two-peptide lantibiotic. Having established that strain C-125 exhibited antimicrobial activity against a wide range of Gram-positive bacteria, it was demonstrated through peptide purification, MS and site-directed mutagenesis that this activity was indeed attributable to the production of a lantibiotic encoded by these genes.

Complete alanine scanning of the two-component lantibiotic lacticin 3147: generating a blueprint for rational drug design.

Lantibiotics are post-translationally modified antimicrobial peptides which are active at nanomolar concentrations. Some lantibiotics have been shown to function by targeting lipid II, the essential precursor of cell wall biosynthesis. Given that lantibiotics are ribosomally synthesized and amenable to site-directed mutagenesis, they have the potential to serve as biological templates for the production of novel peptides with improved functionalities.

Overproduction of wild-type and bioengineered derivatives of the lantibiotic lacticin 3147.

Lacticin 3147 is a broad-spectrum two-peptide lantibiotic whose genetic determinants are located on two divergent operons on the lactococcal plasmid pMRC01. Here we introduce each of 14 subclones, containing different combinations of lacticin 3147 genes, into MG1363 (pMRC01) and determine that a number of them can facilitate overproduction of the lantibiotic. Based on these studies it is apparent that while the provision of additional copies of genes encoding the biosynthetic/production machinery and the regulator LtnR is a requirement for high-level overproduction, the presence of additional copies of the structural genes (i.

Posttranslational conversion of L-serines to D-alanines is vital for optimal production and activity of the lantibiotic lacticin 3147.

As a general rule, ribosomally synthesized polypeptides contain amino acids only in the L-isoform in an order dictated by the coding DNA/RNA. Two of a total of only four examples of L to D conversions in prokaryotic systems occur in posttranslationally modified antimicrobial peptides called lantibiotics. In both examples (lactocin S and lacticin 3147), ribosomally encoded L-serines are enzymatically converted to D-alanines, giving rise to an apparent mistranslation of serine codons to alanine residues.