Determinants of the human infant intestinal microbiota after the introduction of first complementary foods in infant samples from five European centres.

Although it is well established that early infant feeding has a major influence on the establishment of the gut microbiota, very little is understood about how the introduction of first solid food influences the colonization process. This study aimed to determine the impact of weaning on the faecal microbiota composition of infants from five European countries (Sweden, Scotland, Germany, Italy and Spain) which have different lifestyle characteristics and infant feeding practices. Faecal samples were collected from 605 infants approximately 4 weeks after the introduction of first solid foods and the results were compared with the same infants before weaning (6 weeks of age) to investigate the association with determining factors such as geographical origin, mode of delivery, previous feeding method and age of weaning. Samples were analysed by fluorescence in situ hybridization and flow cytometry using a panel of 10 rRNA targeted group- and species-specific oligonucleotide probes. The genus Bifidobacterium (36.5 % average proportion of total detectable bacteria), Clostridium coccoides group (14 %) and Bacteroides (13.6 %) were predominant after weaning. Similar to pre-weaning, northern European countries were associated with a higher proportion of bifidobacteria in the infant gut microbiota while higher levels of Bacteroides and lactobacilli characterized southern European countries. As before weaning, the initial feeding method influenced the Clostridium leptum group and Clostridium difficile+Clostridium perfringens species, and bifidobacteria still dominated the faeces of initially breast-fed infants. Formula-fed babies presented significantly higher proportions of Bacteroides and the C. coccoides group. The mode of birth influenced changes in the proportions of bacteroides and atopobium. Although there were significant differences in the mean weaning age between countries, this was not related to the populations of bifidobacteria or bacteroides. Thus, although the faecal microbiota of infants after first complementary foods was different to that before weaning commenced, many of the initial influences on microbiota composition were still evident.

Faecal microbiota and short-chain fatty acid levels in faeces from infants with cow's milk protein allergy.

BACKGROUND: The present study was designed to compare the faecal microbiota and concentrations of faecal short-chain fatty acid and ammonia between healthy and cow's milk protein allergic (CMPA) infants. METHODS: The population comprised 92 infants aged 2-12 months who were nonallergic (n = 46) or diagnosed as having CMPA (n = 46). Faecal samples were analyzed by fluorescent in situ hybridization and flow cytometry, using a panel of 10 rRNA targeted group- and species-specific oligonucleotide probes. Acetic, propionic, butyric, isocaproic and branched-chain short fatty acids (BCSFA) were measured by gas-liquid chromatography, lactate by enzymatic reaction, and pH and ammonia levels were determined. RESULTS: CMPA infant faeces had significantly higher proportions of the Clostridium coccoides group and Atopobium cluster and a higher sum of the proportions of the different bacterial groups in comparison to healthy infant faeces. Faecal pH and ammonia did not significantly differ between CMPA and healthy infants. Faeces concentrations and percentages of butyric acid and BCSFA were higher in CMPA infants than in healthy infants. CONCLUSIONS: The findings clearly set a link between a dysbiosis in gut microbiota composition and the pathogenesis of CMPA. No single species or genus appeared to play an essential role, but dysbiosis led to biomarkers of CMPA among bacterial fermentation products.

Intestinal microbiota of 6-week-old infants across Europe: geographic influence beyond delivery mode, breast-feeding, and antibiotics.

OBJECTIVES: : There are many differences in diet and lifestyle across Europe that may influence the development of the infant gut microbiota. This work aimed to assess the impact of geographic area, mode of delivery, feeding method, and antibiotic treatment on the fecal microbiota of infants from 5 European countries with different lifestyle characteristics: Sweden, Scotland, Germany, Italy, and Spain. PATIENTS AND METHODS: : Fecal samples from 606 infants (age 6 weeks) recruited within the European project INFABIO were analyzed by fluorescent in situ hybridization combined with flow cytometry using a panel of 10 rRNA targeted group- and species-specific oligonucleotide probes. Information on factors potentially affecting gut microbiota composition was collected with questionnaires and associations were evaluated with multivariate analyses. RESULTS: : The Bifidobacterium genus was predominant (40% average proportion of total detectable bacteria), followed by Bacteroides (11.4%) and enterobacteria (7.5%). Northern European countries were associated with higher proportions of bifidobacteria in infant feces, whereas a more diverse microbiota with more bacteroides characterized southern countries. Bifidobacteria dominated the microbiota of breast-fed infants, whereas formula-fed babies had significantly higher proportions of Bacteroides and members of the Clostridium coccoides and Lactobacillus groups. Newborns delivered by cesarean section or from mothers treated with antibiotics perinatally had lower proportions of Bacteroides and members of the Atopobium cluster. CONCLUSIONS: : Delivery mode and feeding method influenced the fecal microbiota of European infants at 6 weeks, as expected, but the effect of country of birth was more pronounced, with dominant bifidobacteria in northern countries and greater early diversification in southern European countries.

Clostridium difficile and Clostridium perfringens species detected in infant faecal microbiota using 16S rRNA targeted probes.

Clostridium perfringens and Clostridium difficile are pathogenic clostridia potentially associated with gastrointestinal infections and allergy in infants. To enable the molecular detection and quantification of these species in the infant gut, two 16S rRNA oligonucleotide probes were developed: Cdif198 for C. difficile and Cperf191 for C. perfringens. We defined the probes in silico using the RDP sequence database. The probes were then validated using FISH combined with flow cytometry and a collection of target and non-target strains, and faecal samples inoculated with dilutions of C. difficile and C. perfringens strains. These new probes were used to assess the composition of the intestinal microbiota of 33 infants of 1.5 to 18.5 months of age, associated with a panel of 8 probes targeting the predominant faecal bacterial groups of humans. The probes designed allowed detection and quantification of the relative proportions of C. difficile (0.5+/-1.0%) and C. perfringens (2.1+/-2.3%) in the microbiota of infants.

Automated innovative diagnostic, data management and communication tool, for improving malaria vector control in endemic settings.

Malaria is a life-threatening disease that caused more than 400,000 deaths in sub-Saharan Africa in 2015. Mass prevention of the disease is best achieved by vector control which heavily relies on the use of insecticides. Monitoring mosquito vector populations is an integral component of control programs and a prerequisite for effective interventions. Several individual methods are used for this task; however, there are obstacles to their uptake, as well as challenges in organizing, interpreting and communicating vector population data. The Horizon 2020 project "DMC-MALVEC" consortium will develop a fully integrated and automated multiplex vector-diagnostic platform (LabDisk) for characterizing mosquito populations in terms of species composition, Plasmodium infections and biochemical insecticide resistance markers. The LabDisk will be interfaced with a Disease Data Management System (DDMS), a custom made data management software which will collate and manage data from routine entomological monitoring activities providing information in a timely fashion based on user needs and in a standardized way. The ResistanceSim, a serious game, a modern ICT platform that uses interactive ways of communicating guidelines and exemplifying good practices of optimal use of interventions in the health sector will also be a key element. The use of the tool will teach operational end users the value of quality data (relevant, timely and accurate) to make informed decisions. The integrated system (LabDisk, DDMS & ResistanceSim) will be evaluated in four malaria endemic countries, representative of the vector control challenges in sub-Saharan Africa, (Cameroon, Ivory Coast, Ethiopia and Zambia), highly representative of malaria settings with different levels of endemicity and vector control challenges, to support informed decision-making in vector control and disease management.

Isoflavones and functional foods alter the dominant intestinal microbiota in postmenopausal women.

Dietary phytoestrogens, such as isoflavones, are used as food additives to prevent menopause-related disorders. In addition to other factors, their bioavailability strongly depends on the activity of intestinal bacteria but the underlying interactions remain poorly understood. A randomized, double-blind, placebo-controlled study was undertaken with 39 postmenopausal women to characterize changes in the dominant microbial communities of the intestinal tract after 2 mo of isoflavone supplementation with and without pro- or prebiotic. The diversity and composition of the dominant microbiota were analyzed by temporal temperature-gradient gel electrophoresis (TTGE) and fluorescent in situ hybridization. Isoflavones alone stimulated dominant microorganisms of the Clostridium coccoides-Eubacterium rectale cluster, Lactobacillus-Enterococcus group, Faecalibacterium prausnitzii subgroup, and Bifidobacterium genus. The stimulation of the Clostridium coccoides-Eubacterium rectale cluster depended on the women's equol excretion and was transient, with the exception of a prolonged bifidogenic effect. Lasting changes in the diversity of the dominant species were also observed. The probiotic strain supplied could be detected by TTGE during its passage through the intestinal tract, and ingestion of fructooligosaccharides triggered a marked and specific bifidogenic effect. In conclusion, this is the first human study that shows changes in the diversity and composition of dominant bacterial communities in response to dietary supplementation with hormone-related compounds combined with functional foods.