Lisiane Lopes da Conceição

Obesity and diabetes: the link between adipose tissue dysfunction and glucose homeostasis.

Obesity and type 2 diabetes mellitus (T2DM) epidemics, which have already spread, imply the possibility of both conditions being closely related. Thus, the goal of the present review was to draw a parallel between obesity, adipose tissue (AT) changes, and T2DM development. To this end, a search was conducted in PubMed, MEDLINE and SciELO databases, using the following key words and their combinations: obesity; diabetes; insulin resistance; diet; weight loss; adipocin; inflammation markers; and interleukins. Based on a literature review, AT dysfunction observed in obesity is characterised by adipocyte hypertrophy, macrophage infiltration, impaired insulin signalling and insulin resistance. In addition, there is release of inflammatory adipokines and an excessive amount of NEFA promoting ectopic fat deposition and lipotoxicity in muscle, liver and pancreas. Recent evidence supports the hypothesis that the conception of AT as a passive energy storage organ should be replaced by a dynamic endocrine organ, which regulates metabolism through a complex adipocyte communication with the surrounding microenvironment. The present review demonstrates how glucose homeostasis is changed by AT dysfunction. A better understanding of this relationship enables performing nutritional intervention strategies with the goal of preventing T2DM.

Milk kefir: nutritional, microbiological and health benefits.

Kefir is fermented milk produced from grains that comprise a specific and complex mixture of bacteria and yeasts that live in a symbiotic association. The nutritional composition of kefir varies according to the milk composition, the microbiological composition of the grains used, the time/temperature of fermentation and storage conditions. Kefir originates from the Caucasus and Tibet. Recently, kefir has raised interest in the scientific community due to its numerous beneficial effects on health. Currently, several scientific studies have supported the health benefits of kefir, as reported historically as a probiotic drink with great potential in health promotion, as well as being a safe and inexpensive food, easily produced at home. Regular consumption of kefir has been associated with improved digestion and tolerance to lactose, antibacterial effect, hypocholesterolaemic effect, control of plasma glucose, anti-hypertensive effect, anti-inflammatory effect, antioxidant activity, anti-carcinogenic activity, anti-allergenic activity and healing effects. A large proportion of the studies that support these findings were conducted in vitro or in animal models. However, there is a need for systematic clinical trials to better understand the effects of regular use of kefir as part of a diet, and for their effect on preventing diseases. Thus, the present review focuses on the nutritional and microbiological composition of kefir and presents relevant findings associated with the beneficial effects of kefir on human and animal health.

Mechanisms used by inulin-type fructans to improve the lipid profile

AIMS The consumption of prebiotics has been associated with improvement in the lipid profile. Thus, this review aims to describe the main mechanisms by which inulin-type fructans improve the lipid profile and thereby reduce the cardiovascular risk. DATA SYNTHESIS Inulin-type fructans have been demonstrated to improve the lipid profile through a number of mechanisms. These mechanisms include: decrease in gene expression of hepatic enzymes responsible for de novo synthesis of lipids; increase of muscle lipoprotein lipase enzyme activity, enhancing the production of short-chain fatty acids; altered production of polyamines which increases the production of satiogenic peptide; altered blood glucose and insulinemia; increase of fecal excretion of bile salts and cholesterol and increase of the Bifidobacterium population. CONCLUSIONS The consumption of inulin-type fructans enhances lipid profile. Generally, the mechanisms vary according to the physiologic state of the individual and the type of diet to which the inulin-type fructans are added. Thus, inulin may be used for the prevention and/or treatment of cardiovascular diseases.

Review of the mechanisms of probiotic actions in the prevention of colorectal cancer

The purpose of this review is to discuss the potential mechanisms of probiotics action in colorectal cancer prevention. In this regard, the composition of the intestinal microbiota is considered as an important risk factor in the development of colorectal cancer, and probiotics are able to positively modulate the composition of this microbiota. Studies have shown that the regular consumption of probiotics could prevent the development of colorectal cancer. In this respect, in vitro and experimental studies suggest some potential mechanisms responsible for this anticarcinogenic action. The mechanisms include modification of the intestinal microbiota composition, changes in metabolic activity of the microbiota, binding and degradation of carcinogenic compounds present in the intestinal lumen, production of compounds with anticarcinogenic activity, immunomodulation, improvement of the intestinal barrier, changes in host physiology, inhibition of cell proliferation, and induction of apoptosis in cancer cells. In contrast, very few reports demonstrate adverse effects of probiotic oral supplementation. In light of the present evidence, more specific studies are needed on probiotic bacteria, especially regarding the identification of the bacterial strains with greater anticarcinogenic potential; the verification of the viability of these strains after passing through the gastrointestinal tract; the investigation of potential adverse effects in immunocompromised individuals; and finally establishing the dosage and frequency of use.

Mechanisms responsible for the hypocholesterolaemic effect of regular consumption of probiotics

CVD affect a large proportion of the worlds population, with dyslipidaemia as the major risk factor. The regular consumption of both probiotic bacteria and yeast has been associated with improvement in the serum lipid profile. Thus, the present review aims to describe and discuss the potential mechanisms responsible for the hypocholesterolaemic effect of regular consumption of probiotic bacteria and yeast. Regarding the hypocholesterolaemic effect of probiotic bacteria, the potential mechanisms responsible include: deconjugation of bile salts; modulation of lipid metabolism; and decreased absorption of intestinal cholesterol through co-precipitation of intestinal cholesterol with the deconjugated bile salts, incorporation and assimilation of cholesterol in the cell membrane of the probiotics, intestinal conversion of cholesterol in coprostanol, and inhibition of the expression of the intestinal cholesterol transporter Niemann-Pick C1 like 1 (NPC1L1) in the enterocytes. The potential mechanisms responsible for the hypocholesterolaemic effect of probiotic yeasts include: deconjugation of bile salts; co-precipitation of intestinal cholesterol with the deconjugated bile salts; incorporation and assimilation of cholesterol in the cell membrane; and inhibition of hepatic cholesterol synthesis. The regular consumption of probiotic bacteria and yeast, as a non-pharmaceutical approach to help manage cardiovascular risk, holds promise, according to the beneficial hypocholesterolaemic effects described herein. However, the hypocholesterolaemic effects vary according to the strains used, the physiological state of the host, and the type of diet to which the probiotics are added. Further studies are necessary to fill the gaps with regard to the knowledge related to this topic.

Difference in fatty acids composition of breast adipose tissue in women with breast cancer and benign breast disease

INTRODUCTION Breast cancer is the second most common cancer in the world, and the most frequent cancer among women. Moreover, there are factors that influence the risk for breast cancer including the age, genetic and endocrine factors, and lifestyle. OBJECTIVES To evaluate the consumption of fatty acids; compare the fatty acids composition in the breast adipose tissue of women with breast cancer and benign breast disease as well as potential risk factors; and describe the genotypic frequency of the Pro12Ala PPARγ polymorphism. MATERIAL AND METHODS A hospital-based case-control study was conducted including incident cases (n= 38 breast cancer; n= 75 benign breast disease; n= 166 control). Lifestyle features, socioeconomic issues, dietary intake, anthropometry, and blood and tissue data were assessed. RESULTS No differences were observed for fatty acids intake. Interestingly, lauric acid (p = 0.001), myristic acid (p = 0.036), stearic acid (p = 0.031), and total saturated fatty acids (SFAs) (p = 0.048) had lower concentrations in BC than in BBD women, while palmitoleic acid (p = 0.022), erucic acid (p = 0.002), total monounsaturated fatty acids (MUFAs) (p = 0.039) and oleic acid/stearic acid ratio (p = 0.015) increased. There was no significant association between PPARγ polymorphism and studied groups (p = 0.977). The age at first full pregnancy (p = 0.004) was significantly associated with the development BC, whereas BMI (p = 0.005); percentage of body fat (p = 0.024); physical activity (p = 0.036); and age at menarche (p = 0.008), at first full pregnancy (p < 0.001), and of first mammogram (p = 0.018) were significantly associated with the development of BBD. CONCLUSION The results suggest a different fatty acids composition of breast adipose tissue, a biomarker of long-term dietary intake, particularly for SFAs, MUFA and 18: 1 n-9/18: 00 ratio. Our findings also show that are differences in the factors related to the development of BC and BBC.

EFEITO DE PROTETORES E TRATAMENTOS DE ESTRESSE NA SOBREVIVÊNCIA DE LACTOCOCCUS LACTIS SUBSP LACTIS AO CONGELAMENTO Effect of protective and stress treatment on survival of Lactococcus lactis subsp. lactis to freezing

O efeito de substâncias crioprotetoras e de tratamentos subletais de estresse foi avaliado no aumento da tolerância ao congelamento em Lactococcus lactis subsp lactis PD 6.9. Todas as substâncias crioprotetoras avaliadas aumentaram a sobrevivencia de L. lactis subsp lactis PD 6.9 a estocagem de 15 dias a - 20 oC. Entretanto, o leite desnatado reconstituido a 10 % foi o que conferiu maior protecao. Quanto a exposicao da suspensao de celulas a tratamentos subletais de estresse, a exposicao a 10 oC por 4 horas foi capaz de manter a sobrevivencia de L. lactis subsp lactis PD 6.9 estavel durante 70 dias de estocagem a - 20 oC. O tratamento a 40 oC por 30 minutos conferiu protecao durante 70 dias de estocagem a - 20 oC quando comparado com a suspensao de celulas que nao recebeu nenhum tratamento antes do congelamento. A aplicacao desses tratamentos e importante para assegurar a viabilidade de L. lactis subsp lactis PD 6.9 no decorrer do periodo de estocagem, e tambem de assegurar a qualidade sensorial e microbiologica de alimentos obtidos por processos de fermentacao.