Over the last 10–15 years, our understanding of the composition and functions of the human gut microbiota has increased exponentially. To a large extent, this has been due to new ‘omic’ technologies ...that have facilitated large-scale analysis of the genetic and metabolic profile of this microbial community, revealing it to be comparable in influence to a new organ in the body and offering the possibility of a new route for therapeutic intervention. Moreover, it might be more accurate to think of it like an immune system: a collection of cells that work in unison with the host and that can promote health but sometimes initiate disease. This review gives an update on the current knowledge in the area of gut disorders, in particular metabolic syndrome and obesity-related disease, liver disease, IBD and colorectal cancer. The potential of manipulating the gut microbiota in these disorders is assessed, with an examination of the latest and most relevant evidence relating to antibiotics, probiotics, prebiotics, polyphenols and faecal microbiota transplantation.
The present report describes the presentations delivered at the 7th International Yakult Symposium, ‘The Intestinal Microbiota and Probiotics: Exploiting Their Influence on Health’, in London on ...22–23 April 2013. The following two themes associated with health risks were covered: (1) the impact of age and diet on the gut microbiota and (2) the gut microbiota's interaction with the host. The strong influence of the maternal gut microbiota on neonatal colonisation was reported, as well as rapid changes in the gut microbiome of older people who move from community living to residential care. The effects of dietary changes on gut metabolism were described and the potential influence of inter-individual microbiota differences was noted, in particular the presence/absence of keystone species involved in butyrate metabolism. Several speakers highlighted the association between certain metabolic disorders and imbalanced or less diverse microbiota. Data from metagenomic analyses and novel techniques (including an ex vivo human mucosa model) provided new insights into the microbiota's influence on coeliac, obesity-related and inflammatory diseases, as well as the potential of probiotics. Akkermansia muciniphila and Faecalibacterium prausnitzii were suggested as targets for intervention. Host–microbiota interactions were explored in the context of gut barrier function, pathogenic bacteria recognition, and the ability of the immune system to induce either tolerogenic or inflammatory responses. There was speculation that the gut microbiota should be considered a separate organ, and whether analysis of an individual's microbiota could be useful in identifying their disease risk and/or therapy; however, more research is needed into specific diseases, different population groups and microbial interventions including probiotics.
Probiotics- the journey continues Thomas, Linda V
International journal of dairy technology,
11/2016, Volume:
69, Issue:
4
Journal Article
Peer reviewed
Papers from the recent Society of Dairy Technology's spring conference on probiotics are reviewed. Legislation relating to probiotic health claims was outlined, with comparison of the EU with other ...countries, including Japan. Research evidence for numerous probiotic benefits was described, with particular focus on obesity‐related disorders, antibiotic‐associated diarrhoea, infections and cancer. The mechanisms of activity underlying these effects were explained. Research on the gut microbiota early and late in life was presented, with examples of new product development. The physicochemical and microbial considerations for probiotic delivery in a cheese matrix were discussed, and the manufacturing process for galacto‐oligosaccharides used in infant formula was outlined.
Infection with hepatitis B virus (HBV) results in disparate degrees of tissue injury: the virus can either replicate without pathological consequences or trigger immune-mediated necroinflammatory ...liver damage. We investigated the potential for myeloid-derived suppressor cells (MDSCs) to suppress T cell-mediated immunopathology in this setting. Granulocytic MDSCs (gMDSCs) expanded transiently in acute resolving HBV, decreasing in frequency prior to peak hepatic injury. In persistent infection, arginase-expressing gMDSCs (and circulating arginase) increased most in disease phases characterized by HBV replication without immunopathology, whilst L-arginine decreased. gMDSCs expressed liver-homing chemokine receptors and accumulated in the liver, their expansion supported by hepatic stellate cells. We provide in vitro and ex vivo evidence that gMDSCs potently inhibited T cells in a partially arginase-dependent manner. L-arginine-deprived T cells upregulated system L amino acid transporters to increase uptake of essential nutrients and attempt metabolic reprogramming. These data demonstrate the capacity of expanded arginase-expressing gMDSCs to regulate liver immunopathology in HBV infection.
This report summarises talks given at the 8th International Yakult Symposium, held on 23–24 April 2015 in Berlin. Two presentations explored different aspects of probiotic intervention: the small ...intestine as a probiotic target and inclusion of probiotics into integrative approaches to gastroenterology. Probiotic recommendations in gastroenterology guidelines and current data on probiotic efficacy in paediatric patients were reviewed. Updates were given on probiotic and gut microbiota research in obesity and obesity-related diseases, the gut–brain axis and development of psychobiotics, and the protective effects of equol-producing strains for prostate cancer. Recent studies were presented on probiotic benefit for antibiotic-associated diarrhoea and people with HIV, as well as protection against the adverse effects of a short-term high-fat diet. Aspects of probiotic mechanisms of activity were discussed, including immunomodulatory mechanisms and metabolite effects, the anti-inflammatory properties of Faecalibacterium prausnitzii, the relationship between periodontitis, microbial production of butyrate in the oral cavity and ageing, and the pathogenic mechanisms of Campylobacter. Finally, an insight was given on a recent expert meeting, which re-examined the probiotic definition, advised on the appropriate use and scope of the term and outlined different probiotic categories and the prevalence of different mechanisms of activity.
PURPOSE: There is growing evidence that probiotics confer health benefits to the host by modulating immune function, especially in older people, where immunosenescence is a feature even of healthy ...ageing. The aim of this study was to investigate the effect of a probiotic drink containing Lactobacillus casei Shirota (LcS) on immune function in a healthy non-immunocompromised older population. METHODS: Thirty healthy old volunteers were recruited into a randomized placebo-controlled, single-blind crossover study. The volunteers were supplemented with the probiotic drink containing 1.3 × 10¹⁰ CFU LcS or skimmed milk per day for 4 weeks, followed by 4 weeks of washout and were crossed over to the other treatment. Peripheral blood and saliva samples were collected at baseline and end of each treatment. RESULTS: Probiotic consumption was associated with a significant increase in natural killer (NK) cell activity relative to baseline and a significant decrease in the mean fluorescence intensity of CD25 expression in the resting T cells compared with placebo. Additionally, there was a trend towards an increased ratio of IL-10 to IL-12 relative to baseline after LcS intake. CONCLUSIONS: Consumption of a probiotic drink containing LcS improved NK cell activity and tended to produce a more anti-inflammatory cytokine profile in an older population.
Human infection with Mycobacterium bovis is reported infrequently in the United Kingdom. Most cases involve previous consumption of unpasteurized milk. We report a rare occurrence of 2 incidents of ...cat-to-human transmission of M. bovis during a cluster of infection in cats.
Correspondence to Dr Richard Hansen, Department of Paediatric Gastroenterology, Hepatology and Nutrition, Royal Hospital for Children, Glasgow G514TF, UK; richard.hansen@glasgow.ac.uk We read with ...interest the editorial by Baralle and Ismail exploring the utility of next-generation sequencing in paediatric clinical genetics.1 The other major use of this technology, which has emerged over the last decade, is in cataloguing complex microbial communities, for instance the different human microbiomes. Briefly, two main approaches are used to identify and describe bacterial communities using next-generation sequencing: amplicon sequencing (metataxonomics) and metagenomics.2 Amplicon sequencing relies on PCR amplification of a single bacterial ‘housekeeping’ gene (the 16S rRNA gene) which is considered ubiquitous but helpfully contains both highly conserved and variable regions across species. ...a reduction in 11 different bacteria in faeces from children with coeliac disease are specific to that disease state;3 a distinct faecal bacterial cluster described in children postallogenic haematopoietic stem cell transplantation confers distinct prognostic outcomes in terms of subsequent viraemia episodes (unpublished data from author MBE); and exploration of microbiota changes during exclusive enteral nutrition treatment for Crohn’s disease4 has led directly to the development of new solid food approaches to treating the condition.5 If we are to embrace the diagnostic, prognostic and therapeutic revolution offered to us by a greater understanding of the microbiome, there is an urgent need to integrate microbiome analysis into clinical practice.
The present report summarises key insights from a recent symposium focusing on the impact of the intestinal microbiota on health and disease. A more appropriate definition of health was proposed ...since health maintenance is a dynamic process better assessed in terms of ability to adapt to stress and maintain physiological homeostasis. Biomarkers specifically for health are needed; use of challenge models and subjects with suboptimal health or specific disease risk were advised. The complexity of interactions between external factors, the intestinal epithelium, intestinal microbiota, the immune system and health was exemplified by describing the effects of antibiotics, the Western diet and non-digestible carbohydrates on the microbiota. The association of certain bacteria with different states of health or disease was acknowledged but also that is not always clear whether this is a cause or effect. Recent identification of three robust faecal metagenome clusters may advance this understanding. It was speculated that knowledge of the intestinal microbiota profile may eventually help in the diagnosis of health risks and choice of therapy. It was agreed that beneficial manipulation of the commensal microbiota can improve health outcome. For this purpose, three areas were reviewed. Firstly, research into probiotics as vaccine adjuvants was considered useful for substantiation of immune function claims. Secondly, positive results with certain probiotics and synbiotics for colorectal cancer are emerging, mostly from in vitro and animal studies. Finally, studies in endurance athletes have shown strain-specific probiotic benefit in terms of maintenance of immune function and, for certain strains, reduction of episodes of respiratory and/or gastrointestinal tract infections.
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