Susan E. Power

Gut microbiota composition correlates with diet and health in the elderly

Alterations in intestinal microbiota composition are associated with several chronic conditions, including obesity and inflammatory diseases. The microbiota of older people displays greater inter-individual variation than that of younger adults. Here we show that the faecal microbiota composition from 178 elderly subjects formed groups, correlating with residence location in the community, day-hospital, rehabilitation or in long-term residential care. However, clustering of subjects by diet separated them by the same residence location and microbiota groupings. The separation of microbiota composition significantly correlated with measures of frailty, co-morbidity, nutritional status, markers of inflammation and with metabolites in faecal water. The individual microbiota of people in long-stay care was significantly less diverse than that of community dwellers. Loss of community-associated microbiota correlated with increased frailty. Collectively, the data support a relationship between diet, microbiota and health status, and indicate a role for diet-driven microbiota alterations in varying rates of health decline upon ageing.

Intestinal microbiota, diet and health

The human intestine is colonised by 10¹³ to 10¹⁴ micro-organisms, the vast majority of which belong to the phyla Firmicutes and Bacteroidetes. Although highly stable over time, the composition and activities of the microbiota may be influenced by a number of factors including age, diet and antibiotic treatment. Although perturbations in the composition or functions of the microbiota are linked to inflammatory and metabolic disorders (e.g. inflammatory bowel diseases, irritable bowel syndrome and obesity), it is unclear at this point whether these changes are a symptom of the disease or a contributing factor. A better knowledge of the mechanisms through which changes in microbiota composition (dysbiosis) promote disease states is needed to improve our understanding of the causal relationship between the gut microbiota and disease. While evidence of the preventive and therapeutic effects of probiotic strains on diarrhoeal illness and other intestinal conditions is promising, the exact mechanisms of the beneficial effects are not fully understood. Recent studies have raised the question of whether non-viable probiotic strains can confer health benefits on the host by influencing the immune system. As the potential health effect of these non-viable bacteria depends on whether the mechanism of this effect is dependent on viability, future research needs to consider each probiotic strain on a case-by-case basis. The present review provides a comprehensive, updated overview of the human gut microbiota, the factors influencing its composition and the role of probiotics as a therapeutic modality in the treatment and prevention of diseases and/or restoration of human health.

Food and nutrient intake of Irish community-dwelling elderly subjects: who is at nutritional risk?

Objectives: To assess the dietary intakes of Irish community-dwelling elderly individuals, participating in the ELDERMET project. Design: Cross-sectional study. Setting: Cork city and county region of southern Ireland. Participants: Two hundred and eight (94 males, 114 females) community-dwelling subjects aged 64-93 yrs. Measurements: Dietary intake was assessed using a validated semi-quantitative food frequency questionnaire (FFQ). Anthropometric data were recorded. Nutritional status was assessed using the Mini Nutritional Assessment (MNA). Results: A high rate of overweight/obesity was observed in this population group. Consumption of energy-dense, low-nutrient foods was excessive among this population group. Older elderly subjects (≥75 yrs) consumed significantly (P<0.01) more desserts/sweets than younger elderly (64–74 yrs). Intakes of dietary fat and saturated fat were high while dairy food consumption was inadequate in both males and females. Elderly females typically had a more nutrient-dense diet than males. A considerable proportion of subjects, particularly males, had inadequate intakes of calcium, magnesium, vitamin D, folate, zinc and vitamin C. Conclusion: The data indicate that the diet of Irish community-dwelling elderly individuals is suboptimal with respect to nutrient intake, and excessive in terms of fat intake, with implications for the health status of this population group. Reductions in dietary fat and increased low fat dairy food intakes are recommended for the prevention of diet-related disease in older persons. In addition, strategies to improve a number of sub-optimal micronutrient intakes need to be developed and implemented, particularly among elderly males.

Metabolic Syndrome and Obesity in Adults

The relatively recent discovery that changes in the composition and metabolic activity of the gut microbiota are associated with obesity and related disorders has led to an explosion of interest in this now distinct research field. In the following chapter, we discuss the current evidence related to how the modulation of gut microbial populations might have beneficial effects with respect to controlling obesity. A number of studies in both animals and humans have shown that the composition of the gut microbiota is significantly altered in obesity and diabetes. Strategies including specific functional foods, probiotics, and prebiotics have the potential to favorably influence host metabolism by targeting the gut microbiota. Indeed, probiotics appear to be a promising approach to alter the host metabolic alterations linked to the changes in the gut microbiota. However, the mechanisms by which probiotics may impact on the development of obesity and metabolic health remain unclear and require further investigation.

Draft Genome Sequence of Lactobacillus crispatus EM-LC1, an Isolate with Antimicrobial Activity Cultured from an Elderly Subject

ABSTRACT Here we report the 1.86-Mb draft genome sequence of Lactobacillus crispatus EM-LC1, a fecal isolate with antimicrobial activity. This genome sequence is expected to provide insights into the antimicrobial activity of L. crispatus and improve our knowledge of its potential probiotic traits.

Gender differences in food intake among Irish community-dwelling elderly subjects: The ELDERMET project

The proportion of citizens older than 65 years of age in Western populations is increasing. It is therefore important to investigate the fundamental role of diet in the prevention of age-associated chronic disease. In addition, gender differences in food consumption and nutrient intakes are well recognised, and need to be further explored and addressed. The aim of this study was to establish the frequency of consumption of the major food groups within a cohort of elderly, Irish subjects (n = 210; 113 male and 97 female 64–93 y), who participated in the ELDERMET project. Dietary data was collected using a validated semi-quantitative, 147-item food frequency questionnaire (FFQ). Individual food and beverage items were aggregated into 30 (mutually exclusive) food groups. Median daily serving intake was calculated and statistical analysis was conducted using PASW2 (version 18.0) for two age categories, 64–75 yrs and ‡ 76 yrs. Females (64–75y) consumed significantly (P<0.05) more unrefined wholegrain cereals, dietary supplements, salad dressings, probiotic yoghurts, fresh soups, fish, hot beverages and fruit than males. Males of the same age range consumed significantly (P<0.05) more processed soups, meat products, soft drinks, alcohol, meat and refined cereals (see table). Cross-gender, food group variance among the more senior group (n = 102) was limited to alcohol intake; with males consuming significantly more than females (P<0.05). In addition, females from both age groups showed higher compliance rates with the recently revised Irish dietary guidelines for adults aged >51 y.

Fish-oil consumption is inversely correlated with depression and cognition decline in healthy Irish elderly adults

Epidemiological studies investigating associations between diet and cognitive function suggest a protective role for fish and fish-oil consumption in cognitive decline and depression, particularly among elderly populations. As longevity increases and elderly subjects become an increasing proportion of populations worldwide, it is important to establish dietary components associated with healthy brain aging. The aim of this study was to evaluate fish and fish-oil consumption in a sample of healthy, community-dwelling Irish adults and to explore the association between fish and fish oil consumption, and cognitive function and depression score. Fish and fish product intakes, cognitive function and depressive symptoms were assessed among community-dwelling, elderly adults (n = 172; age 64–93 yrs) who participated in the ELDERMET project. Fish and fish product consumption was evaluated using a 147-item, validated, semi-quantitative Food Frequency Questionnaire, where fish intakes were categorized into the following groups; processed/fried fish, white fish, oily fish, shellfish and fish-oil supplements. The Mini Mental State Exam (MMSE) and Geriatric Depression Scale (GDS) were used to determine cognitive function and depressive symptoms, respectively. Among the fish and fish-products assessed, white fish was consumed most frequently, by 84% of the group, with 72% of consumers complying with recommended intakes of one or more servings of white fish/wk. Seventy-six percent of the group consumed oily fish with 64% complying with recommendations. Shellfish consumption was lowest at 31%. Consumption and compliance to recommended intakes was highest among females for all fish and fish-products, except for processed/fried fish consumption, which was higher among males. Fish-oils were consumed by 19% of the group, of which 55% were female. No significant correlation was observed between white fish consumption and GDS (Pearson correlation coefficient r = 0.007; P = 0.97) and MMSE (r = 0.007; P = 0.928). Similarly for oily fish, there was no association between GDS (r = 0.072; P = 0.427) and MMSE> (r = 0.052; P = 0.497), indicating no positive effect of either white or oily fish consumption on improved depressive symptoms or cognitive function. However, an inverse association was found between fish-oil supplement consumption and GDS (r = 0.229; P = 0.010); suggesting an association between reduced depressive symptoms and increased fish-oil consumption. In addition, a trend for association between fish-oil consumption with MMSE (r = 0.145; P = 0.057) was also observed, whereby increasing fish-oil consumption was associated with a trend for improved cognitive function. In conclusion, fish consumption was comparable with a nationally representative sample of healthy, elderly Irish individuals. However gender differences indicate better compliance with guidelines among females. Further studies investigating the effect of fish-oil consumption on cognitive function and depressive symptoms in elderly groups are warranted. Fish consumption should be promoted in the elderly as it may prevent brain ageing processes and reduce cognitive decline.

Response to Letter to the Editor from Dr. Kawada regarding the article Dietary glycaemic load and cognitive performance in elderly subjects

In his offered opinion piece, (Dietary glycaemic load and cognitive performance in elderly subjects) Dr. Kawada comments upon the statistical analysis and suggests that the conclusions of the study should be interpreted with caution. Having closely examined these comments, we believe that they are over-stated and we draw different conclusions. At first viewing, the statistical arguments put forward by Dr. Kawada look complicated, but one may summarize that he believes the analysis lacked statistical power. This argument is directed towards two sets of regression analyses, a Poisson analysis on which one of the messages of the paper hinges, and a second logistic analysis that was acknowledged as statistically underpowered in our publication. No statistical argument is provided as to why the Poisson regression model is underpowered; the critique contains no new scientific content but relies on a technical re-iteration of the limitations of the study (that were highlighted in the original manuscript) combined with quasi philosophical arguments on data set size and the need for biochemical markers in observational dietary studies.

Compliance with Irish food-based dietary guidelines in elderly subjects recruited from rehabilitation wards and out-patient clinics in Southern region hospitals (The ELDERMET project)

The elderly population are an “at-risk” group for under-nutrition which is associated with longer duration in hospitalised care as well as increased prevalence of morbidity and mortality. Identifying food consumption patterns and the contribution of the main food groups to nutritional status is essential to identify those at risk of underor over-nutrition. The aim of this study was to establish the frequency of consumption of the major food groups in two groups of elderly Irish subjects, who participated in the ELDERMET project, and to explore their compliance with the recently revised Irish food based dietary recommendations. Subjects were recruited from rehabilitation wards (n 62; aged 65–93 y) and out-patient clinics (n 45; aged 67–92 y) in two Southern region hospitals. Dietary data was collected using a validated semi-quantitative, food frequency questionnaire (FFQ). Daily food group consumption was estimated and compared to Irish food-based dietary guidelines. Over 82% of rehab and out-patient subjects complied with the recommended number of servings for breads, cereals and potatoes. In addition, both groups consumed adequate fruit and vegetables (see Table) with 51.6% of rehab and 53.3% of out-patient subjects meeting recommendations to consume 5+ servings per day. However, poor compliance was evident for dairy-rich foods with only 14.5% of rehab and 4.4% of out-patient subjects meeting recommendations. Compliance with recommendations for low-nutrient dense foods, high in fat and/or sugar for rehab and out-patients was also particularly low in both groups at 6.5% and 13.3%, respectively. In addition, 53.2% of rehab and 66.7% of out-patient subjects were classified as overweight or obese according to Body Mass Index (BMI). This high rate of overweight and obesity is in line with general healthy population trends.

Consumption of fruit and vegetables among elderly Irish people in long-term institutionalised care: the ELDERMET project

Fruit and vegetables are an important source of vitamins and minerals such as vitamin C, folate, K and b-carotene . High fruit and vegetable consumption may reduce the risk of several chronic diseases, including cancers, CVD, hypertension and stroke. The benefits of fruit and vegetable consumption continue into old age. In fact, with advancing age the requirements for some antioxidants may be increased. The Irish food-based dietary guidelines therefore recommends consumption of at least five portions of fruit and vegetables daily. The aim of this study was to establish the frequency of consumption of fruit and vegetables within a sample of institutionalised elderly, Irish subjects (n 99; twenty-six men and seventy-three women; aged 66–104 years), who participated in the ELDERMET project. Dietary data was collected using a validated semi-quantitative, 147-item FFQ. Fruit and vegetables that contributed to the recommended five portions a day included all fresh, frozen and canned fruit and vegetables, pure fruit drinks, dried fruit, vegetable soups, tomato-based pasta sauces, baked beans and other pulses. Potatoes and nuts were excluded. In order to estimate the number of servings of fruit and vegetables consumed on a daily basis, frequency of consumption was converted to a single daily serving. The number of servings of fruit and vegetables was then calculated by adding the daily value for each relevant fruit/vegetable item. Statistical analysis was conducted using PASW (version 18.0). Overall, fruit and vegetable intake was below the recommended 5+ servings (see Table). The most commonly consumed vegetables were carrots, parsnips/turnips and cabbage, while the most commonly consumed fruit items were pure fruit drinks, bananas and apples. A large proportion of subjects (71.7%) did not meet recommendations to consume 5 + servings of fruit and vegetables daily. Almost half (46.5%) of these subjects consumed less than three servings a day. Percentage compliance with recommendations for other food groups was also poor. Over all, one-fifth (21.2%) of subjects consumed dietary supplements (including vitamin and mineral supplements) on a daily basis that may contribute to vitamin and mineral intakes.