Changes in the intestinal microbiota from adulthood through to old age

AbstractThe human intestinal microbiota comprises a complex community whose composition has been resolved in fine detail by recent culture-independent methodologies. The adult intestinal microbiota is stable within individuals, and individual specific when examined at high resolution. Infants and older persons, however, represent stages of life in which the microbiota is in flux. Since changes in the intestinal microbiota are associated with certain diseases or health issues, we have examined the composition and function of the intestinal microbiota in 500 subjects over 65 years of age in Ireland. Medical, biochemical and immunological parameters were measured for all subjects. Faecal microbiota was measured by amplicon pyrosequencing. The data revealed significant inter-individual variation, especially in the proportions of some major bacterial phyla, and significant differences in the microbiota compared with younger adults. These data support the notion of modulating the intestinal microbiota of older people to promote enhanced nutrition utilization and to improve general healt

The role of the microbiota in sedentary life style disorders and ageing: lessons from the animal kingdom

A paradox of so‐called developed countries is that, as the major historical causes of human mortality are eliminated or mitigated by medical progress, life‐style related diseases have become major killers. Furthermore, as life‐span is extended by the combined effects of modern medicine, health‐span is struggling to keep apace because of the burden of non‐communicable diseases linked to diet and sedentary life‐style. The gut microbiome is now recognized as a plastic environmental risk factor for many of these diseases, the microbiome being defined as the complex community of co‐evolved commensal microbes that breaks down components of a complex diet, modulates innate immunity, and produces signalling molecules and metabolites that can impact on diverse regulatory systems in mammals. Aspects of the so‐called “Western” life‐style linked to disease risk such as energy dense diet and antibiotic treatment are known to affect the composition and function of the microbiome. Here we review the detailed mechanisms whereby the gut microbiome may modulate risk of diseases linked to sedentary life‐style, and ageing related health loss. We focus on the comparative value of natural animal models such as hibernation for studying metabolic regulation, and the challenge of extrapolating from animal models to processes that occur in human ageing

The potential of non-starter lactic acid bacteria from Cheddar cheese to colonise the gut

peer-reviewedThis study was undertaken to assess the potential of Non-Starter Lactic Acid Bacteria (NSLAB) from Cheddar cheese to survive gastric transit and display probiotic-related traits including bile salt hydrolase activity, the ability to adhere to the gut epithelium and inhibition of enteropathogen binding. Populations of NSLAB, up to 107 CFU/g per cheese were recovered following exposure of cheese to Simulated Stomach Duodenum Passage (SSDP) conditions. A total of 240 isolates were randomly selected from twelve Cheddar cheeses and assessed for probiotic traits. Two strains Lactobacillus paracasei DPC 7150 and Lactobacillus rhamnosus DPC 7102 showed the most probiotic potential. The Lb. paracasei and Lb. rhamnosus strains displayed adhesion rates of 64% and 79%, respectively and inhibited binding of pathogenic Escherichia coli by >20%. This research demonstrates that Cheddar cheese harbours potentially beneficial bacteria, a large portion of which can survive simulated digestion and potentially exhibit health beneficial effects once ingested.TEAGAS

The potential of non-starter lactic acid bacteria from Cheddar cheese to colonise the gut

peer-reviewedThis study was undertaken to assess the potential of Non-Starter Lactic Acid Bacteria (NSLAB) from Cheddar cheese to survive gastric transit and display probiotic-related traits including bile salt hydrolase activity, the ability to adhere to the gut epithelium and inhibition of enteropathogen binding. Populations of NSLAB, up to 107 CFU/g per cheese were recovered following exposure of cheese to Simulated Stomach Duodenum Passage (SSDP) conditions. A total of 240 isolates were randomly selected from twelve Cheddar cheeses and assessed for probiotic traits. Two strains Lactobacillus paracasei DPC 7150 and Lactobacillus rhamnosus DPC 7102 showed the most probiotic potential. The Lb. paracasei and Lb. rhamnosus strains displayed adhesion rates of 64% and 79%, respectively and inhibited binding of pathogenic Escherichia coli by >20%. This research demonstrates that Cheddar cheese harbours potentially beneficial bacteria, a large portion of which can survive simulated digestion and potentially exhibit health beneficial effects once ingested

Diet influences the functions of the human intestinal microbiome

Gut microbes programme their metabolism to suit intestinal conditions and convert dietary components into a panel of small molecules that ultimately affect host physiology. To unveil what is behind the effects of key dietary components on microbial functions and the way they modulate host\u2013microbe interaction, we used for the first time a multi-omic approach that goes behind the mere gut phylogenetic composition and provides an overall picture of the functional repertoire in 27 fecal samples from omnivorous, vegan and vegetarian volunteers. Based on our data, vegan and vegetarian diets were associated to the highest abundance of microbial genes/proteins responsible for cell motility, carbohydrate- and protein-hydrolyzing enzymes, transport systems and the synthesis of essential amino acids and vitamins. A positive correlation was observed when intake of fiber and the relative fecal abundance of flagellin were compared. Microbial cells and flagellin extracted from fecal samples of 61 healthy donors modulated the viability of the human (HT29) colon carcinoma cells and the host response through the stimulation of the expression of Toll-like receptor 5, lectin RegIII\u3b1 and three interleukins (IL-8, IL-22 and IL-23). Our findings concretize a further and relevant milestone on how the diet may prevent/mitigate disease risk

Towards standards for human fecal sample processing in metagenomic studies

Technical variation in metagenomic analysis must be minimized to confidently assess the contributions of microbiota to human health. Here we tested 21 representative DNA extraction protocols on the same fecal samples and quantified differences in observed microbial community composition. We compared them with differences due to library preparation and sample storage, which we contrasted with observed biological variation within the same specimen or within an individual over time. We found that DNA extraction had the largest effect on the outcome of metagenomic analysis. To rank DNA extraction protocols, we considered resulting DNA quantity and quality, and we ascertained biases in estimates of community diversity and the ratio between Gram-positive and Gram-negative bacteria. We recommend a standardized DNA extraction method for human fecal samples, for which transferability across labs was established and which was further benchmarked using a mock community of known composition. Its adoption will improve comparability of human gut microbiome studies and facilitate meta-analyses

Analysis of shared heritability in common disorders of the brain

Paroxysmal Cerebral Disorder

Maintenance of a healthy trajectory of the intestinal microbiome during aging: A dietary approach

Sharing an intense transgenomic metabolism with the host, the intestinal microbiota is an essential factor for several aspects of the human physiology. However, several age-related factors, such as changes diet, lifestyle, inflammation and frailty, force the deterioration of this intestinal microbiota-host mutualistic interaction, compromising the possibility to reach longevity. In this scenario, the NU-AGE project involves the development of dietary interventions specifically tailored to the maintenance of a healthy trajectory of the intestinal microbiome, counteracting all processes connected to the pathophysiology of the human agin

Maintenance of a healthy trajectory of the intestinal microbiome during aging: A dietary approach

Sharing an intense transgenomic metabolism with the host, the intestinal microbiota is an essential factor for several aspects of the human physiology. However, several age-related factors, such as changes diet, lifestyle, inflammation and frailty, force the deterioration of this intestinal microbiota-host mutualistic interaction, compromising the possibility to reach longevity. In this scenario, the NU-AGE project involves the development of dietary interventions specifically tailored to the maintenance of a healthy trajectory of the intestinal microbiome, counteracting all processes connected to the pathophysiology of the human agin