Role of Microorganisms Present in Dairy Fermented Products in Health and Disease

Non peer reviewe

Impact of intrapartum antimicrobial prophylaxis upon the intestinal microbiota and the prevalence of antibiotic resistance genes in vaginally delivered full-term neonates

Background: Disturbances in the early establishment of the intestinal microbiota may produce important implications for the infant's health and for the risk of disease later on. Different perinatal conditions may be affecting the development of the gut microbiota. Some of them, such as delivery mode or feeding habits, have been extensively assessed whereas others remain to be studied, being critical to identify their impact on the microbiota and, if any, to minimize it. Antibiotics are among the drugs most frequently used in early life, the use of intrapartum antimicrobial prophylaxis (IAP), present in over 30% of deliveries, being the most frequent source of exposure. However, our knowledge on the effects of IAP on the microbiota establishment is still limited. The aim of the present work was to evaluate the impact of IAP investigating a cohort of 40 full-term vaginally delivered infants born after an uncomplicated pregnancy, 18 of which were born from mothers receiving IAP. Results: Fecal samples were collected at 2, 10, 30, and 90 days of age. We analyzed the composition of the fecal microbiota during the first 3 months of life by 16S rRNA gene sequencing and quantified fecal short chain fatty acids by gas chromatography. The presence of genes for resistance to antibiotics was determined by PCR in the samples from 1-month-old infants. Our results showed an altered pattern of intestinal microbiota establishment in IAP infants during the first weeks of life, with lower relative proportions of Actinobacteria and Bacteroidetes and increased of Preoteobacteria and Firmicutes. A delay in the increase on the levels of acetate was observed in IAP infants. The analyses of specific antibiotic resistance genes showed a higher occurrence of some beta-lactamase coding genes in infants whose mothers received IAP. Conclusions: Our results indicate an effect of IAP on the establishing early microbiota during the first months of life, which represent a key moment for the development of the microbiota-induced host homeostasis. Understanding the impact of IAP in the gut microbiota development is essential for developing treatments to minimize it, favoring a proper gut microbiota development in IAP-exposed neonates

Insights into Microbe-Microbe Interactions in Human Microbial Ecosystems: Strategies to be Competitive

All parts of our body having communication with the external environment such as the skin, vagina, the respiratory tract or the gastrointestinal tract are colonized by a specific microbial community. The colon is by far the most densely populated organ in the human body. The pool of microbes inhabiting our body is known as “microbiota” and their collective genomes as “microbiome”. These microbial ecosystems regulate important functions of the host, and their functionality and the balance among the diverse microbial populations is essential for the maintenance of a “healthy status”. The impressive development in recent years of next generation sequencing (NGS) methods have made possible to determine the gut microbiome composition. This, together with the application of other high throughput omic techniques and the use of gnotobiotic animals has greatly improved our knowledge of the microbiota acting as a whole. In spite of this, most members of the human microbiota are largely unknown and remain still uncultured. The final functionality of the microbiota is depending not only on nutrient availability and environmental conditions, but also on the interrelationships that the microorganisms inhabiting the same ecological niche are able to establish with their partners, or with their potential competitors. Therefore, in such a competitive environment microorganisms have had to develop strategies allowing them to cope, adapt, or cooperate with their neighbors, which may imply notable changes at metabolic, physiological and genetic level. The main aim of this Research Topic was to contribute to better understanding complex interactions among microorganisms residing in human microbial habitats.All parts of our body having communication with the external environment such as the skin, vagina, the respiratory tract or the gastrointestinal tract are colonized by a specific microbial community. The colon is by far the most densely populated organ in the human body. The pool of microbes inhabiting our body is known as “microbiota” and their collective genomes as “microbiome”. These microbial ecosystems regulate important functions of the host, and their functionality and the balance among the diverse microbial populations is essential for the maintenance of a “healthy status”. The impressive development in recent years of next generation sequencing (NGS) methods have made possible to determine the gut microbiome composition. This, together with the application of other high throughput omic techniques and the use of gnotobiotic animals has greatly improved our knowledge of the microbiota acting as a whole. In spite of this, most members of the human microbiota are largely unknown and remain still uncultured. The final functionality of the microbiota is depending not only on nutrient availability and environmental conditions, but also on the interrelationships that the microorganisms inhabiting the same ecological niche are able to establish with their partners, or with their potential competitors. Therefore, in such a competitive environment microorganisms have had to develop strategies allowing them to cope, adapt, or cooperate with their neighbors, which may imply notable changes at metabolic, physiological and genetic level. The main aim of this Research Topic was to contribute to better understanding complex interactions among microorganisms residing in human microbial habitats

Development of functional foods to fight against obesity : opportunities for probiotics and prebiotics

Obesity is a complex and multifactorial disorder that has become one of most prevalent health issues of the 21st century. Recent evidence suggests that an altered composition and functionality of the gut microbiota plays a key role in the increased prevalence of obesity. In this regard, gut microbiota modulation through the diet emerges as an efficient approach for the management of obesity. We provide an overview of the current evidence regarding the potential benefits of functional foods containing probiotics and prebiotics on reduction of weight and body fat and the use of these nutritional ingredients for the development of tailor-made solutions to fight against the epidemic of obesity

Different metabolic features of Bacteroides fragilis growing in the presence of glucose and exopolysaccharides of bifidobacteria

Bacteroides is among the most abundant microorganism inhabiting the human intestine. They are saccharolytic bacteria able to use dietary or host-derived glycans as energy sources. Some Bacteroides fragilis strains contribute to the maturation of the immune system but it is also an opportunistic pathogen. The intestine is the habitat of most Bifidobacterium species, some of whose strains are considered probiotics. Bifidobacteria can synthesize exopolysaccharides (EPS), which are complex carbohydrates that may be available in the intestinal environment. We studied the metabolism of B. fragilis when an EPS preparation from bifidobacteria was added to the growth medium compared to its behavior with added glucose. 2D-DIGE coupled with the identification by MALDI-TOF/TOF evidenced proteins that were differentially produced when EPS was added. The results were supported by RT-qPCR gene expression analysis. The intracellular and extracellular pattern of certain amino acids, the redox balance and the α-glucosidase activity were differently affected in EPS with respect to glucose. These results allowed us to hypothesize that three general main events, namely the activation of amino acids catabolism, enhancement of the transketolase reaction from the pentose-phosphate cycle, and activation of the succinate-propionate pathway, promote a shift of bacterial metabolism rendering more reducing power and optimizing th

The human intestinal microbiome at extreme ages of life. Dietary intervention as a way to counteract alterations

The intestinal microbiome is defined as the assembly of genomes from microorganisms inhabiting the gut. This microbial ecosystem regulates important functions of the host and its correct composition and functionality is essential for a healthy status. Metagenomic studies have highlighted variations of the intestinal microbiota as a function of age and diet. Colonization of the infant gut starts at birth and is influenced by feeding habits (formula vs. breast-feeding), birth mode and antibiotic exposure. The intestinal microbiota of full-term vaginally-delivered breast-fed infants is considered the gold-standard of a healthy infant microbiota, representing the reference for studies of alterations in other pediatric populations. At two to three years of age, the intestinal microbiota reaches a composition similar to adults, remaining without noticeable variations until senescence, when microbial instability and changes reappear. Here we summarize the current knowledge on intestinal microbiota alterations at extreme stages of life and tools for designing differentiated nutritional strategies by the use of probiotics, prebiotics and specific nutrients in order to restore a balanced microbiota and to improve immune and nutritional status

Bifidobacterium breve IPLA20005 affects “in vitro” the expression of hly and LuxS genes, related to the virulence of Listeria monocytogenes Lm23

Mechanistic features about the interaction and inhibition of the food borne pathogen Listeria monocytogenes by members of the genus Bifidobacterium still remain unclear. In the present work we tried to shed light into the influence that co-cultivation of L. monocytogenes with Bifidobacterium breve may exert on both microorganisms and on the pathogen virulence. Production of acetate and lactate was measured by gas chromatography and HPLC respectively, bacterial counts were obtained by plate count, gene expression was determined by RT-qPCR and the hemolytic activity was analyzed against goat erythrocytes. We found a slight but significantly lower final counts of Listeria and Bifidobacterium (PThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Co-culture affects protein profile and heat tolerance of Lactobacillus delbrueckii subsp. lactis and Bifidobacterium longum

Some strains of the genus Bifidobacterium are considered probiotics and can be added as adjunct cultures to functional dairy products. Lactobacillus delbrueckii subsp. lactis is used as a starter in food fermentations. The influence of co-culturing strains Bifidobacterium longum NCIMB 8809 and L. delbrueckii subsp. lactis 193 on the physiology and heat tolerance of these microorganisms was studied. 2DE coupled to MS protein analysis allowed the identification of several proteins from each bacterium whose expression changed when cells were grown in compartmentalized co-cultures compared to mono-cultures. Remarkably, production of stress response chaperones was enhanced in both strains and was related with increased survival to heat shock, a technologically suitable property in the manufacture of some dairy products. This study provides the first insight in understanding communication between B. longum and L. delbrueckii subsp. lactis. © 2013 Elsevier Ltd.Fil: Sanchez, Borja. Consejo Superior de Investigaciones Científicas. Instituto Superior de Productos Lacteos de Asturias; España;Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto de Lactologia Industrial; ArgentinaFil: Ruiz, Lorena. Consejo Superior de Investigaciones Científicas. Instituto Superior de Productos Lacteos de Asturias; España;Fil: Binetti, Ana Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto de Lactologia Industrial; ArgentinaFil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto de Lactologia Industrial; ArgentinaFil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto de Lactologia Industrial; ArgentinaFil: Margolles, Abelardo. Consejo Superior de Investigaciones Científicas. Instituto Superior de Productos Lacteos de Asturias; España;Fil: Ruas Madiedo, Patricia. Consejo Superior de Investigaciones Científicas. Instituto Superior de Productos Lacteos de Asturias; España;Fil: de Los Reyes-Gavilan, Clara G.. Consejo Superior de Investigaciones Científicas. Instituto Superior de Productos Lacteos de Asturias; España