The intestinal microbiota has increasingly been shown to have a vital role in various aspects of human health. Indeed, several studies have linked alterations in the gut microbiota with the ...development of different diseases. Among the vast gut bacterial community, Bifidobacterium is a genus which dominates the intestine of healthy breast-fed infants whereas in adulthood the levels are lower but relatively stable. The presence of different species of bifidobacteria changes with age, from childhood to old age. Bifidobacterium longum, B. breve, and B. bifidum are generally dominant in infants, whereas B. catenulatum, B. adolescentis and, as well as B. longum are more prevalent in adults. Increasingly, evidence is accumulating which shows beneficial effects of supplementation with bifidobacteria for the improvement of human health conditions ranging from protection against infection to different extra- and intra-intestinal positive effects. Moreover, bifidobacteria have been associated with the production of a number of potentially health promoting metabolites including short chain fatty acids, conjugated linoleic acid and bacteriocins. The aim of this mini-review is to describe the bifidobacteria compositional changes associated with different stages in life, highlighting their beneficial role, as well as their presence or absence in many disease states.
Solutions are urgently required for the growing number of infections caused by antibiotic-resistant bacteria. Bacteriocins, which are antimicrobial peptides produced by certain bacteria, might ...warrant serious consideration as alternatives to traditional antibiotics. These molecules exhibit significant potency against other bacteria (including antibiotic-resistant strains), are stable and can have narrow or broad activity spectra. Bacteriocins can even be produced in situ in the gut by probiotic bacteria to combat intestinal infections. Although the application of specific bacteriocins might be curtailed by the development of resistance, an understanding of the mechanisms by which such resistance could emerge will enable researchers to develop strategies to minimize this potential problem.
It is well established that the gut microbiota plays an important role in host health and is perturbed by several factors including antibiotics. Antibiotic‐induced changes in microbial composition ...can have a negative impact on host health including reduced microbial diversity, changes in functional attributes of the microbiota, formation, and selection of antibiotic‐resistant strains making hosts more susceptible to infection with pathogens such as Clostridioides difficile. Antibiotic resistance is a global crisis and the increased use of antibiotics over time warrants investigation into its effects on microbiota and health. In this review, we discuss the adverse effects of antibiotics on the gut microbiota and thus host health, and suggest alternative approaches to antibiotic use.
Antibiotics can have several negative impacts on host health; both direct and indirect effects. The gut microbiota plays a crucial role in host health regulation. Effects of antibiotics on the host through the gut microbiome are immense and can affect various functions including immune regulation, metabolic activities, and thus overall health.
Over the last two decades our understanding of the gut microbiota and its contribution to health and disease has been transformed. Among a new 'generation' of potentially beneficial microbes to have ...been recognized are members of the genus Eubacterium, who form a part of the core human gut microbiome. The genus consists of phylogenetically, and quite frequently phenotypically, diverse species, making Eubacterium a taxonomically unique and challenging genus. Several members of the genus produce butyrate, which plays a critical role in energy homeostasis, colonic motility, immunomodulation and suppression of inflammation in the gut. Eubacterium spp. also carry out bile acid and cholesterol transformations in the gut, thereby contributing to their homeostasis. Gut dysbiosis and a consequently modified representation of Eubacterium spp. in the gut, have been linked with various human disease states. This review provides an overview of Eubacterium species from a phylogenetic perspective, describes how they alter with diet and age and summarizes its association with the human gut and various health conditions.
Bacteriocin Production: a Probiotic Trait? DOBSON, Alleson; COTTER, Paul D; ROSS, R. Paul ...
Applied and Environmental Microbiology,
01/2012, Letnik:
78, Številka:
1
Journal Article
Gut microbiota, obesity and diabetes Patterson, Elaine; Ryan, Paul M; Cryan, John F ...
Postgraduate medical journal,
05/2016, Letnik:
92, Številka:
1087
Journal Article
Recenzirano
Odprti dostop
The central role of the intestinal microbiota in the progression and, equally, prevention of metabolic dysfunction is becoming abundantly apparent. The symbiotic relationship between intestinal ...microbiota and host ensures appropriate development of the metabolic system in humans. However, disturbances in composition and, in turn, functionality of the intestinal microbiota can disrupt gut barrier function, a trip switch for metabolic endotoxemia. This low-grade chronic inflammation, brought about by the influx of inflammatory bacterial fragments into circulation through a malfunctioning gut barrier, has considerable knock-on effects for host adiposity and insulin resistance. Conversely, recent evidence suggests that there are certain bacterial species that may interact with host metabolism through metabolite-mediated stimulation of enteric hormones and other systems outside of the gastrointestinal tract, such as the endocannabinoid system. When the abundance of these keystone species begins to decline, we see a collapse of the symbiosis, reflected in a deterioration of host metabolic health. This review will investigate the intricate axis between the microbiota and host metabolism, while also addressing the promising and novel field of probiotics as metabolic therapies.
Purpose
The study aimed to investigate the discrepancy and potential mechanisms of different CLA-producing
B. breve
on dextran sulphate sodium (DSS)-induced colitis.
Methods
Colitis was induced in ...C57BL/6 J mice using DSS. Disease activity index (DAI), histopathological changes, epithelial barrier integrity and epithelial apoptosis were determined. Gut microbiota were gauged to evaluate the systemic effects of CLA-producing
B. breve
.
Results
Oral administration of different
B. breve
showed different effects, in which
B. breve
M1 and
B. breve
M2 alleviated the inflammation induced by DSS as well as significantly increased the concentration of mucin2 (MUC2) and goblet cells, but neither
B. breve
M3 nor
B. breve
M4 had those protective effects. Meanwhile,
B. breve
M1 and
B. breve
M2 treatments significantly up-regulated the tight junction (TJ) proteins and ameliorated the epithelial apoptosis lead by DSS challenge. Moreover, inflammatory cytokines (TNF-α, IL-6) were modulated by
B. breve
M1 and
B. breve
M2, neither
B. breve
M3 nor
B. breve
M4. Furthermore,
B. breve
M1 and
B. breve
M2 reduced the abundance of
Bacteroides
and increased the abundance of
Odoribacter
, then rebalanced the damaged gut microbiota. Colonic CLA concentrations in mice fed with
B. breve
M1,
B. breve
M2,
B. breve
M3 and
B. breve
M4 decreased successively, which showed significant positive correlation with the effectiveness of relieving colitis.
Conclusions
Bifidobacterium breve
M1 and
B. breve
M2 alleviated DSS-induced colitis by producing CLA, inhibiting the inflammatory cytokines, maintaining of the intestinal epithelial barrier and regulating the gut microbiota.
Perinatal factors impact gut microbiota development in early life, however, little is known on the effects of these factors on microbes in later life. Here we sequence DNA from faecal samples of ...children over the first four years and reveal a perpetual evolution of the gut microbiota during this period. The significant impact of gestational age at birth and delivery mode on gut microbiota progression is evident in the first four years of life, while no measurable effects of antibiotics are found in the first year. Microbiota profiles are also characteristic in children dependant on gestational age and maturity. Full term delivery is characterised by Bacteroides (year one), Parabacteroides (year two) and Christensenellaceae (year four). Preterm delivery is characterised by Lactobacillus (year one), Streptococcus (year two) and Carnobacterium (year four). This study reveals that the gut retains distinct microbial profiles of perinatal factors up to four years of age.
Summary Background There are no systemic treatments for patients with hepatocellular carcinoma (HCC) whose disease progresses during sorafenib treatment. We aimed to assess the efficacy and safety of ...regorafenib in patients with HCC who have progressed during sorafenib treatment. Methods In this randomised, double-blind, parallel-group, phase 3 trial done at 152 sites in 21 countries, adults with HCC who tolerated sorafenib (≥400 mg/day for ≥20 of last 28 days of treatment), progressed on sorafenib, and had Child-Pugh A liver function were enrolled. Participants were randomly assigned (2:1) by a computer-generated randomisation list and interactive voice response system and stratified by geographical region, Eastern Cooperative Oncology Group performance status, macrovascular invasion, extrahepatic disease, and α-fetoprotein level to best supportive care plus oral regorafenib 160 mg or placebo once daily during weeks 1–3 of each 4-week cycle. Investigators, patients, and the funder were masked to treatment assignment. The primary endpoint was overall survival (defined as time from randomisation to death due to any cause) and analysed by intention to treat. This trial is registered with ClinicalTrials.gov , number NCT01774344. Findings Between May 14, 2013, and Dec 31, 2015, 843 patients were screened, of whom 573 were enrolled and randomised (379 to regorafenib and 194 to placebo; population for efficacy analyses), and 567 initiated treatment (374 received regorafenib and 193 received placebo; population for safety analyses). Regorafenib improved overall survival with a hazard ratio of 0·63 (95% CI 0·50–0·79; one-sided p<0·0001); median survival was 10·6 months (95% CI 9·1–12·1) for regorafenib versus 7·8 months (6·3–8·8) for placebo. Adverse events were reported in all regorafenib recipients (374 100% of 374) and 179 (93%) of 193 placebo recipients. The most common clinically relevant grade 3 or 4 treatment-emergent events were hypertension (57 patients 15% in the regorafenib group vs nine patients 5% in the placebo group), hand–foot skin reaction (47 patients 13% vs one 1%), fatigue (34 patients 9% vs nine patients 5%), and diarrhoea (12 patients 3% vs no patients). Of the 88 deaths (grade 5 adverse events) reported during the study (50 patients 13% assigned to regorafenib and 38 20% assigned to placebo), seven (2%) were considered by the investigator to be related to study drug in the regorafenib group and two (1%) in the placebo group, including two patients (1%) with hepatic failure in the placebo group. Interpretation Regorafenib is the only systemic treatment shown to provide survival benefit in HCC patients progressing on sorafenib treatment. Future trials should explore combinations of regorafenib with other systemic agents and third-line treatments for patients who fail or who do not tolerate the sequence of sorafenib and regorafenib. Funding Bayer.
The Gut Microbiota of Marine Fish Egerton, Sian; Culloty, Sarah; Whooley, Jason ...
Frontiers in microbiology,
05/2018, Letnik:
9
Journal Article
Recenzirano
Odprti dostop
The body of work relating to the gut microbiota of fish is dwarfed by that on humans and mammals. However, it is a field that has had historical interest and has grown significantly along with the ...expansion of the aquaculture industry and developments in microbiome research. Research is now moving quickly in this field. Much recent focus has been on nutritional manipulation and modification of the gut microbiota to meet the needs of fish farming, while trying to maintain host health and welfare. However, the diversity amongst fish means that baseline data from wild fish and a clear understanding of the role that specific gut microbiota play is still lacking. We review here the factors shaping marine fish gut microbiota and highlight gaps in the research.
PDF
