Maternal soy protein isolate diet during lactation programs deleterious effects on hepatic lipid metabolism, atherogenic indices, and function of adrenal in adult rat offspring.

The benefits of consuming soy and its protein have been reported in many studies. However, its phytoestrogen content raises concerns about consumption during lactation and gestation We therefore examined the effects of soybean or soy protein isolate on the parameters-related cardiovascular pathophysiology in lactating mothers and their offsprings at weaning and adulthood. Lactating rats were divided: casein control (C); soy protein isolate (SPI); and soybean (S). At weaning, half of the litter received commercial ration up to 150 days. The levels of 17-ß-estradiol and superoxide dismutase were low in the S mothers. For the SPI mothers, we observed a reduction of thiobarbituric acid reactive substances (TBARS). At weaning, atherogenic indices [1 = total cholesterol (TC)/HDL; 2 = LDL/HDL; 3 = TC-HDL/HDL)] decreased in the S and SPI offsprings compared to the casein control group; TBARS and antioxidant enzymes increased in the S offspring, while reduced/oxidized glutathione ratio increased in the SPI offspring, indicating lower oxidative stress. In adulthood, the SPI offspring showed an increase in liver cholesterol and atherogenic index 1 and 3 (vs. C and S) and 2 (vs. S). In addition, we found a decrease in catecholamines in the adrenal medulla and an increase in caffeine-stimulated secretion, but tyrosine hydroxylase expression remained constant. Maternal consumption of SPI during lactation worsened atherogenic indices of the offsprings in adulthood, which was associated with increased liver cholesterol and decreased catecholamines in the adrenal medulla. Soy consumption had no consistent long-term effects on the evaluated parameters compared to casein consumption. The data suggest that the consumption of SPI during lactation should be done with caution.

Preclinical Evidence of Probiotics in Colorectal Carcinogenesis: A Systematic Review.

BACKGROUND: Colorectal cancer, the second major cause of cancer deaths, imposes a major health burden worldwide. There is growing evidence that supports that the use of probiotics is effective against various diseases, especially in gastrointestinal diseases, including the colorectal cancer, but the differences between the strains, dose, and frequency used are not yet clear. AIMS: To perform a systematic review to compile the results of studies carried out in animal models and investigated the effect of probiotics on colorectal carcinogenesis. METHODS: Studies were selected in PubMed/MEDLINE and Scopus according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Search filters were developed using three parameters: probiotics, colorectal cancer, and animal model. RESULTS: From a structured search, we discovered 34 original articles and submitted them to a risk of bias analysis using SYRCLE's tool. The studies show a great diversity of models, most were conducted in rats (55.8%) and used 1,2 dimethylhydrazine as the drug to induce colorectal carcinogenesis (61.7%). The vast majority of trials investigated Lactobacillus (64%) and Bifidobacterium (29.4%) strains. Twenty-six (86.6%) studies found significant reduction in lesions or tumors in the animals that received probiotics. The main methodological limitation was the insufficient amount of information for the adequate reproducibility of the trials, which indicated a high risk of bias due to incomplete characterization of the experimental design. CONCLUSIONS: The different probiotics' strains showed anti-carcinogenic effect, reduced the development of lesions and intestinal tumors, antioxidant and immunomodulatory activity, and reduced fecal bacterial enzymes.

Obesity, Xenobiotic Intake and Antimicrobial-Resistance Genes in the Human Gastrointestinal Tract: A Comparative Study of Eutrophic, Overweight and Obese Individuals.

Although lifestyle and physiology in obese individuals are accepted to lead to changes in the intestinal microbiota, uncertainty remains about microbiota dysbiosis, and xenobiotics intake, as a source of selective pressure, independent of antimicrobial chemotherapy. The aim of this study was to compare the occurrence of antimicrobial resistance genetic markers (ARG) in faecal specimens of eutrophic, overweight and obese individuals, and their correlation with xenobiotic intake and gut bacteria density. Methods: This was a cross-sectional case-controlled study including 72 adult participants with no record of intestinal or systemic diseases, or recent use of antimicrobials, grouped as eutrophic, overweight, or obese. Anthropometric profile, eating habits and oral xenobiotics intake were recorded. Faecal metagenomic DNA was used to screen for ARG by PCR, and to measure bacterial groups by fluorescence in situ hybridization (FISH). Student's t and Wilcoxon tests were used to compare means and differences in ARG detection (95% confidence intervals). Correlation analyses (odds ratio) and relationships between bacteria density and ARG were determined. Results: Increase in abdominal circumference, waist circumference, hip, waist-hip ratio, BMI, carbohydrate, fibres, and total calorie intakes were different from eutrophic to obese participants. Habitual use of antihypertensive and anti-inflammatory drugs, antacids, and artificial sweeteners were associated mainly with obesity and overweight. Nutritional supplements were associated to the eutrophic group. ARG screening showed differences being more frequent among obese, and positive for 27 genetic markers related to ß-lactams, tetracyclines, the macrolide lincosamide and streptogramin group, quinolones, sulfonamides, aminoglycosides, and efflux pump. Positive correlation between ARG and BMI, caloric intake, and intake of xenobiotics, was observed for obese individuals. Relationships among ARG detection and bacteria densities were also different. Conclusions: This study reinforces the hypothesis that obese individuals may harbour an altered gut microbiota, if compared to eutrophic. The overweight individuals display a transitional gut microbiota which seems to be between eutrophic and obese. Furthermore, the increased xenobiotic intake associated to obesity may play an important role in the antimicrobial resistance phenomenon.

Cis-9, trans-11 and trans-10, cis-12 CLA mixture does not change body composition, induces insulin resistance and increases serum HDL cholesterol level in rats.

Synthetic supplements of conjugated linoleic acid (CLA) containing 50:50 mixture of cis-9, trans-11 and trans-10, cis-12 CLA isomers have been commercialized in some places for reducing body fat. However the safety of this CLA mixture is controversial and in some countries the CLA usage as food supplement is not authorized. Changes in insulinemic control and serum lipids profile are potential negative effects related to consumption of CLA mixture. The present study aimed to evaluate the effects of a diet containing mixture of cis-9, trans-11 and trans-10, cis-12 CLA on prevention of obesity risk as well as on potential side effects such as insulin resistance and dyslipidemia in Wistar rats. Thirty male Wistar rats were randomly assigned to the following dietary treatments (n=10/group), for 60 days: Normolipidic Control (NC), diet containing 4.0% soybean oil (SO); High Fat-Control (HF-C), diet containing 24.0% SO; High Fat-synthetic CLA (HF-CLA), diet containing 1.5% of an isomeric CLA mixture (Luta-CLA 60) and 22.5% SO. Luta-CLA 60 (BASF) contained nearly 60% of CLA (cis-9, trans-11 and trans-10, cis-12 CLA at 50:50 ratio). The HF-CLA diet contained 0.3% of each CLA isomer. HF-CLA diet had no effect on dietary intake and body composition. HF-CLA-fed rats had lower levels of PPARγ protein in retroperitoneal adipose tissue, hyperinsulinemia compared to HF-C-fed rats, hyperglycemia compared to NC-fed rats while no differences in glycemia were observed between NC and HF-C groups, increased HOMA index and higher levels of serum HDL cholesterol. Thus, feeding rats with a high fat diet containing equal parts of cis-9, trans-11 and trans-10, cis-12 CLA isomers had no effect on body composition and induced insulin resistance. Despite HF-CLA-fed rats had increased serum HDL cholesterol levels, caution should be taken before synthetic supplements containing cis-9, trans-11 and trans-10, cis-12 CLA are recommended as a nutritional strategy for weight management.