Emerging Evidence on the Use of Probiotics and Prebiotics to Improve the Gut Microbiota of Older Adults with Frailty Syndrome: A Narrative Review.

BACKGROUND: The gut microbiota can impact older adults' health, especially in patients with frailty syndrome. Understanding the association between the gut microbiota and frailty syndrome will help to explain the etiology of age-related diseases. Low-grade systemic inflammation is a factor leading to geriatric disorders, which is known as "inflammaging". Intestinal dysbiosis has a direct relationship with low-grade systemic inflammation because when the natural gut barrier is altered by age or other factors, some microorganisms or their metabolites can cross this barrier and reach the systemic circulation. OBJECTIVES: This review had two general goals: first, to describe the characteristics of the gut microbiota associated with age-related diseases, specifically frailty syndrome. The second aim was to identify potential interventions to improve the composition and function of intestinal microbiota, consequently lessening the burden of patients with frailty syndrome. METHODS: A search of scientific evidence was performed in PubMed, Science Direct, and Redalyc using keywords such as "frailty", "elderly", "nutrient interventions", "probiotics", and "prebiotics". We included studies reporting the effects of nutrient supplementation on frailty syndrome and older adults. These studies were analyzed to identify novel therapeutic alternatives to improve gut microbiota characteristics as well as subclinical signs related to this condition. RESULTS: The gut microbiota participates in many metabolic processes that have an impact on the brain, muscles, and other organs. These processes integrate feedback mechanisms, comprising their respective axis with the intestine and the gut microbiota. Alterations in these associations can lead to frailty. We report a few interventions that demonstrate that prebiotics and probiotics could modulate the gut microbiota in humans. Furthermore, other nutritional interventions could be used in patients with frailty syndrome. CONCLUSION: Probiotics and prebiotics may potentially prevent frailty syndrome or improve the quality of life of patients with this disorder. However, there is not enough information about their appropriate doses and periods of administration. Therefore, further investigations are required to determine these factors and improve their efficacy as therapeutic approaches for frailty syndrome.

Effect of Chronic Consumption of Sweeteners on Microbiota and Immunity in the Small Intestine of Young Mice.

The consumption of sweeteners has increased as a measure to reduce the consumption of calories and thus combat obesity and diabetes. Sweeteners are found in a large number of products, so chronic consumption has been little explored. The objective of the study was to evaluate the effect of chronic sweetener consumption on the microbiota and immunity of the small intestine in young mice. We used 72 CD1 mice of 21 days old, divided into 3 groups: (i) No treatment, (ii) Group A (6 weeks of treatment), and (iii) Group B (12 weeks of treatment). Groups A and B were divided into 4 subgroups: Control (CL), Sucrose (Suc), Splenda® (Spl), and Svetia® (Sv). The following were determined: anthropometric parameters, percentage of lymphocytes of Peyer's patches and lamina propria, IL-6, IL-17, leptin, resistin, C-peptide, and TNF-α. From feces, the microbiota of the small intestine was identified. The BMI was not modified; the mice preferred the consumption of Splenda® and Svetia®. The percentage of CD3+ lymphocytes in Peyer's patches was increased. In the lamina propria, Svetia® increased the percentage of CD3+ lymphocytes, but Splenda® decreases it. The Splenda® and Svetia® subgroups elevate leptin, C-peptide, IL-6, and IL-17, with reduction of resistin. The predominant genus in all groups was Bacillus. The chronic consumption of sweeteners increases the population of lymphocytes in the mucosa of the small intestine. Maybe, Bacillus have the ability to adapt to sweeteners regardless of the origin or nutritional contribution of the same.

Effect of Supplementation with n-3 Fatty Acids Extracted from Microalgae on Inflammation Biomarkers from Two Different Strains of Mice.

BACKGROUND: Diabetes mellitus is considered a chronic noncommunicable disease in which inflammation plays a main role in the progression of the disease and it is known that n-3 fatty acids have anti-inflammatory properties. One of the most recent approaches is the study of the fatty acids of microalgae as a substitute for fish oil and a source rich in fatty acids EPA and DHA. OBJECTIVE: To analyze the effect of supplementation with n-3 fatty acids extracted from microalgae on the inflammatory markers from two different strains of mice. METHODS: Mice of two strains, db/db and CD1, were supplemented with n-3 fatty acids extracted from microalgae in lyophilized form and added to food; the experiment was carried out from week 8 to 16 of life. Flow cytometry was performed to determine the percentage of TCD4+ cells producing Th1 and Th2 cytokines. RESULTS: Supplementation with microalgae fatty acids decreased the percentage of TCD4+ cells producing IFN-γ and TNF-α and increased the ones producing IL-17A and IL-12 in both strains; on the other hand, supplementation decreased percentage of TCD4+ cells producing IL-4 and increased the ones producing TGF-ß. CONCLUSIONS: Microalgae n-3 fatty acids could be a useful tool in the treatment of diabetes as well as in the prevention of the appearance of health complications caused by inflammatory states.

Effect of Diet and Exercise on the Peripheral Immune System in Young Balb/c Mice.

Although diet and exercise clearly have an influence on immune function, studies are scarce on the effect caused by exercise and the consumption of a carbohydrate-rich or fat-rich diet on the peripheral immune system. The aim of the present study was to evaluate the effect of exercise and the two aforementioned unbalanced diets on young Balb/c mice, especially in relation to BMI, the level of glucose, and the percentage of lymphocyte subpopulations in peripheral blood. The changes found were then related to the synthesis of leptin and adiponectin as well as the production of oxidative stress. The increase in BMI found with the carbohydrate-rich and fat-rich diets showed correlation with the levels of leptin and adiponectin. An increase in leptin and a decrease in adiponectin directly correlated with an increase in total lymphocytes and CD4+ cells and with a decrease in B cells. The increase in leptin also correlated with an increase in CD8+ cells. Glycemia and oxidative stress increased with the two unbalanced diets, negatively affecting the proliferation of total lymphocytes and the percentage of B cells, apparently by causing alterations in proteins through carbonylation. These alterations caused by an unbalanced diet were not modified by moderate exercise.

Can the degree of concordance with recommendations for a cancer prevention diet and lifestyle be assessed from existing survey information data?

BACKGROUND: The World Cancer Research Fund convened an expert committee who analyzed the literature related to the causation of human cancers. Recommendations for preventing cancer through behavioral practices were formatted into a 14-point guideline. OBJECTIVE: We parsed the cancer prevention guidelines to determine to what extent relevant information on individual behavior could be assessed from conventional food-frequency questionnaires, which are being used in surveys conducted in developing countries. DESIGN: We examined a convenience sample of archival forms completed during 2 independent studies (a case-control and a field study) that used an adapted Willett food-frequency questionnaire that was translated into Spanish for use in Guatemala. RESULTS: All dietary related guidelines, except for salt, were evaluated by both questionnaires. Physical activity, food handling, and food preparation were not addressed by either of the questionnaires, although body mass index and dietary supplements were addressed in the case-control study and field-study questionnaires, respectively. CONCLUSIONS: Although concordance with some of the cancer prevention goals and guidelines can be evaluated from the existing questionnaires, adjustments and additions must be made with respect to salt and supplement use, physical activity, and food handling. Actual weight and height measurements are also needed, particularly in low-income populations.

[Nutrition status evaluation of the women at reproductive age. Uses and limitations]. / Evaluación del estado de nutrición de la mujer en edad reproductiva. Usos y limitaciones.

Information is given about the main methods for nutrition status evaluation of the woman, this information is oriented to three stages of the woman's life cycle: adult stage, gestation stage and lactation stage. The usefulness as well as the limitations of the diet surveys are discussed. The main anthropometric indicators are presented, useful in the clinical practice to evaluate nutrition status of the non-pregnant woman (body mass index, waist/hip index and skinfolds), pregnant woman (percentage of expected weight for height and gestation age, weight gain during pregnancy, height of fundus of uterus, arm circumference and skinfolds) and lactating woman (weight loss and skinfolds). The most important nutrition status biochemical indicators are discussed. At last some special evaluation technics as measurements of body composition and balance methods are discussed.

[Evaluation of a breakfast as screening test for the detection of gestational diabetes]. / Evaluación de un desayuno como prueba de tamiz para la detección de diabetes gestacional.

A standard breakfast was evaluated as a screening test (BT) for gestational diabetes in a case-control study. The breakfast had a high carbohydrate content and was designed based on women's preferences in a similar sample. Women were selected with a standard 50 g, 1 hour glucose screening test (GT). Fifteen women had a positive GT and 15 had a negative test. A glucose tolerance test (GTT) and a standard breakfast (719 kcal) were performed to all women. Age, weight, height, tricipital and subscapular skinfold thicknesses were obtained by previously standardized personnel and glucose levels were determined by an automatic technique (oxidase glucose). Ten women had gestational diabetes. Sensitivity and specificity were calculated for the GT and several values of the BT, in order to identify the threshold and optimum time. Concordance of both screening tests with GTT was calculated through Kappa test. For the BT, a sensitivity of 0.90 and specificity of 1.00 with a glucose level > or = 140 mg/L (7.2 mmol/L) at 60 and 90 minutes were found. The 60 minutes timing were preferred due to a shorter waiting time to performed the test. Concordance of GTT with GT and BT was 0.53 and 0.92 respectively, both statistically significant. GT had high frequency of false negative values (6/15) that explain the low kappa value. Standard breakfast can be used as an alternative method for assessing carbohydrate tolerance in pregnancy with a better physiological response in these women.

Inflammatory mediators and immune response in Mexican adolescents.

INTRODUCTION: Low-grade inflammation and increased immunity related to cardiovascular diseases have been described in children and adults, however, studies in Mexican adolescents are being done at present. OBJECTIVE: To evaluate inflammatory proteins and indicators of immunity in adolescents by gender and body mass index. MATERIAL AND METHODS: 115 Mexican adolescents, 15-18 years old (36 men), were divided into non-overweight, risk of overweight and overweight by CDC pediatric criteria by body mass index. Serum concentrations of ceruloplasmin, C3 and C4 were quantified by nephelometry; IL-6 and TNF-α from stimulated supernatant were analyzed with Human Th1-Th2 cytokine CBA II kit (BD Biosciences Pharmigen, San Diego, CA), and detected by flow cytometry. Data were analysed by Mann-Whitney U. RESULTS: Gender differences were found in C3 (men: median 118.8, mean rank: 41.0; women: median: 143.9, mean rank: 65.7, p=0.001) and ceruloplasmin (men: median: 31.01, mean rank: 47.06; women: median: 31.0, mean rank: 62.9, p=0.015). Differences by BMI were found in C3 (women non-overweight: median: 137.00 mena rank: 36.52; women with risk of overweight/overweight: median: 175.80, mean rank: 57.69, p=0.002) and C4 (men non-overweight: median: 23.40, mean rank: 16.60; men with risk of overweight/overweight: median: 26.40, mean rank: 26.36, p=0.028; women non-overweight: median: 24.25, mean rank: 37.16 and women with risk of overweight/overweight: median: 32.80, mean rank: 54.42, p=0.013). CONCLUSION: Inflammatory proteins are increased in adolescents with risk of overweight and overweight, particularly in women.

Zinc: a perinatal point of view.

Zinc is a metal with great nutritional importance, particularly during periods of rapid growth due to its intervention in cellular replication as well as in the development of the immune response. A review of studies by several authors trying to determine the normal behaviour of zinc during pregnancy and early infancy is done, in an attempt to establish adequate circulating levels, in order to be able to identify zinc deficiency correctly and provide appropriate treatment. However, the information is very contradictory and no real conclusion can be reached.

[Serum retinol in urban Mexican women during the perinatal period]. / Retinol sérico en mujeres mexicanas urbanas durante el periodo perinatal.

OBJECTIVE: To establish the prevalence of vitamin A deficiency during pregnancy and lactation in a group of urban Mexican women. MATERIAL AND METHODS: A group of pregnant women who attended a prenatal care program were invited to participate. Subjects had no added pathologies and were less than 20 weeks pregnant. Evaluations were performed 3 times during pregnancy until 24 weeks post-partum. Vitamin A levels were determined in serum by high performance liquid chromatography (HPLC). The cut-off point to consider retinol deficiency was < 1.05 mumol/L. RESULTS: During the 3 gestational evaluations, vitamin A levels were 2.34 +/- 0.70, 2.41 +/- 1.03 and 1.86 +/- 0.66 mumol/L, respectively, which shows a significant decrease. However, only 1/30 was situated below the accepted cut-off point to consider risk of deficiency, and none for deficiency. During post-partum, concentrations remained relatively constant, approximately 2.10 mumol/L. Lactation had no impact on serum retinol levels, while weight loss did. CONCLUSIONS: No cases of vitamin A deficiency were found in the studied population during the perinatal period. Maternal weight loss affects post-partum retinol levels.