Lactobacillaceae and Cell Adhesion: Genomic and Functional Screening

The analysis of collections of lactic acid bacteria (LAB) from traditional fermented plant foods in tropical countries may enable the detection of LAB with interesting properties. Binding capacity is often the main criterion used to investigate the probiotic characteristics of bacteria. In this study, we focused on a collection of 163 Lactobacillaceace comprising 156 bacteria isolated from traditional amylaceous fermented foods and seven strains taken from a collection and used as controls. The collection had a series of analyses to assess binding potential for the selection of new probiotic candidates. The presence/absence of 14 genes involved in binding to the gastrointestinal tract was assessed. This enabled the detection of all the housekeeping genes (ef-Tu, eno, gap, groEl and srtA) in the entire collection, of some of the other genes (apf, cnb, fpbA, mapA, mub) in 86% to 100% of LAB, and of the other genes (cbsA, gtf, msa, slpA) in 0% to 8% of LAB. Most of the bacteria isolated from traditional fermented foods exhibited a genetic profile favorable for their binding to the gastrointestinal tract. We selected 30 strains with different genetic profiles to test their binding ability to non-mucus (HT29) and mucus secreting (HT29-MTX) cell lines as well as their ability to degrade mucus. Assays on both lines revealed high variability in binding properties among the LAB, depending on the cell model used. Finally, we investigated if their binding ability was linked to tighter cross-talk between bacteria and eukaryotic cells by measuring the expression of bacterial genes and of the eukaryotic MUC2 gene. Results showed that wild LAB from tropical amylaceous fermented food had a much higher binding capacity than the two LAB currently known to be probiotics. However their adhesion was not linked to any particular genetic equipment

Evaluation of silent cerebral lesions in patients with first ischemic stroke attack

Background: We aimed to evaluate the frequency of silent cerebral lesions (silent cerebral infarction (SCI) and leukoaraiosis (LA)) in first-ever ischemic stroke patients. We wanted to identify the risk factors related with silent cerebral lesions, and the impact of these lesions on the prognosis of patients. Materials and methods: A total of 114 (58 male/56 female) patients with first-ever ischemic stroke that underwent brain MRI were enrolled in this study. Clinical features, and laboratory results were compared in the patients with and without SCI. They were also compared with LA severity, and the risk factors were evaluated. Results: SCI was detected in 90 patients and the most common location was periventricular white matter (PWM) (33%). High body mass index (BMI), hypertension (HT), and hyperlipidemia (HL) were associated with SCI (p = 0.023, 0.012, and 0.019). No associations were detected with LA (p > 0.05). The cholesterol (p = 0.011) and LDL (p = 0.009) levels of the multiple-SCI group were higher than those of the single-SCI group. Lower ejection fraction (EF) was associated with SCI and the severity of LA (p = 0.029 and 0.036). Hemoglobin and hematocrit values were low in advanced-periventricular white matter hyperintensity (adv-PWMH).The presence of SCI had no effects, on stroke recurrence, mortality, or prognosis. Multiple logistic regression analysis showed that HL and the presence of adv-PWMH were independent risk factors for SCI. Conclusion: While some parameters are associated with presence of SCI and LA, other parameters are related only with presence of LA. Different factors may play a role in development of SCI and LA. Studies on larger populations are needed for further evaluation of this issue. © 2011 Elsevier GmbH. All rights reserved

Underlying evidence for the health benefits of fermented foods in humans

International audienceFermented foods (FFs) have been a part of our diets for millennia and comprise highly diverse products obtained from plants and animals all over the world. Historically, fermentation has been used to preserve food and render certain raw materials edible. As our food systems evolve towards more sustainability, the health benefits of FFs have been increasingly touted. Fermentation generates new/transformed bioactive compounds that may occur in association with probiotic bacteria. The result can be specific, advantageous functional properties. Yet, when considering the body of human studies on the topic, whether observational or experimental, it is rare to come across findings supporting the above assertion. Certainly, results are lacking to confirm the widespread idea that FFs have general health benefits. There are some exceptions, such as in the case of lactose degradation via fermentation in individuals who are lactose intolerant; the impact of select fermented dairy products on insulin sensitivity; or the benefits of alcohol consumption. However, in other situations, the results fail to categorically indicate whether FFs have neutral, beneficial, or detrimental effects on human health. This review tackles this apparent incongruity by showing why it is complex to test the health effects of FFs and what can be done to improve knowledge in this field