Probiotics and Inflammatory Status in Patients With Heart Failure

Overview

Cachexia is a very common condition in patients with advanced heart failure (HF) and is considered a predictor of mortality. Studies have been carried out in an attempt to discover the mechanisms that leads to cachexia in order to improve the therapies and the survival of these patients. Some of these studies give the hypothesis that the gastrointestinal tract, more precisely the intestine, can collaborate with cachexia. Some of these studies suggest that, the intestinal mucosa, due to hypoperfusion, becomes more permeable to some substances, as like endotoxins, being the lipopolysaccharide (LPS) one of them. The circulating LPS can stimulate the increase of tumor necrosis alpha (TNF-alpha) further increasing the inflammation and, consequently, contributing to the worsening of prognosis. The intestinal microbiota is also affected by hypoperfusion, contributing with increase of permeability. As known, probiotics can help to maintain or recover the microbiota and maintain a healthy intestinal barrier. In view of the importance of microbiota to inflammation in the prognosis of the patients and the performance of microbiota in maintenance of intestinal barrier, this study has as primary objective to verify the influence of supplementation of the probiotic Lactobacillus acidophilus (LA) in the lowering of serum levels of TNF-alpha in the patients with HF.

The present study will be a clinical trial compounded by two parallel arms, randomized, double-blind (researcher-patient), placebo-controlled, with patients with heart failure (HF), functional class according the New York Heart Association (NYHA) III and IV. It will be included 58 patients, 29 will receive probiotics and 29 will receive placebo. These patients will be accompanied during 6 months and should take one capsule every day during the study. In the beginning of the study and at the end, venous blood sample will be collected of each patient for laboratory measurement of TNF alpha, interleukins 1,6 and 10, LPS, B-type natriuretic peptide (BNP) and C-reactive protein (CRP). To establish the normality pattern of these markers studied, a control group, with healthy individuals, will be performed.An anthropometric evaluation will be performed with measurements of weigh, height, arm circumference, triceps skin fold. According to nutritional status, it will be calculated the caloric and protein needs of each patient and, to monitor the consumption, in each consult will be applied the 24-hour food recall and calculated the consumption from it. In order to measure the appetite of the patients, in each consult, an appetite questionnaire will be applied. To statistical analysis, the test of Kolmogorov-Smirnov will be used to assess whether the distribution is normal for the quantitative variables. If the variable follows normal distribution, it will be described as mean and standard deviation, otherwise, it will be described as median and interquartile range. The groups will be compared using t-Student or Mann-Whitney tests. The categorical variables will be presented descriptively with absolute and relative frequencies. The association between categorical variables will be analyzed with chi square test or Fisher exact test or likelihood ratio test. For the repeated measures, will be used the ANOVA test or Friedman test and Wilcoxon signs. The analyzes will be performed according to the intent-to-treat principle and the two-tailed tests. The value of p\<0,5 will be considered statistically significant.