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Aim The composition of faecal microbiota of babies is known to be influenced by diet. Faecal calprotectin and α1-antitrypsin concentrations may be associated with mucosal permeability and inflammation. We aimed to assess whether there was any difference after consumption of a probiotic/prebiotic formula on faecal microbiota composition, calprotectin and α1-antitrypsin levels, and diarrhoea in comparison with breast milk-fed Indonesian infants. Methods One hundred sixty infants, 2 to 6 weeks old, were recruited to the study. They were either breastfed or formula fed (80 per group). Faecal samples were collected at recruitment and 3 months later. Bacterial groups characteristic of the human faecal microbiota were quantified in faeces by quantitative polymerase chain reaction. Calprotectin and α1-antitrypsin concentrations were measured using commercial kits. Details of diarrhoeal morbidity were documented and rated for severity. Results The compositions of the faecal microbiota of formula-fed compared with breast milk-fed children were similar except that the probiotic strain Bifidobacterium animalis subsp. lactisâ€...DR10 was more abundant after 3 months consumption of the formula. Alpha1-antitrypsin levels were higher in breastfed compared with formula-fed infants. The occurrence of diarrhoea did not differ between the groups of babies. Conclusion Feeding Indonesian babies with a probiotic/prebiotic formula did not produce marked differences in the composition of the faecal microbiota in comparison with breast milk. Detrimental effects of formula feeding on biomarkers of mucosal health were not observed.

BACKGROUND: Allergic disease has been associated with altered intestinal microbiota. Therefore, probiotics have been suggested as a potential treatment for eczema. OBJECTIVE: We investigated whether dietary supplementation of infants with eczema at age 3-6 months with Lactobacillus paracasei CNCM I-2116 or Bifidobacterium lactis CNCM I-3446 had a treatment effect or altered allergic disease progression. METHODS: Primary outcome included eczema severity (SCORing Atopic Dermatitis, SCORAD) 3 months post-randomization. Secondary: SCORAD (other visits); infant dermatitis quality of life (IDQoL); gastrointestinal permeability; urinary eosinophilic protein X; allergen-sensitization; allergic symptoms (age 12, 18, 36 months). A total of 208 infants aged 3-6 months with physician-diagnosed eczema were recruited; 137/208 (SCORAD ? 10, consuming ? 200 mL standard formula/day) were randomized to daily supplements containing L. paracasei or B. lactis or placebo for a 3-month period, while receiving extensively hydrolysed whey-formula (dairy-free diet). There were two open observational groups, one group exclusively breastfed (n = 22) and the other, standard formula-fed (n = 49). TRIAL NUMBER: ISRCTN41490500. RESULTS: Eczema severity decreased significantly over time in all groups. No significant difference was observed between randomized groups after 12-week treatment-period (SCORAD-score pre-/post-intervention: B. lactis 25.9 [95% CI: 22.8-29.2] to 12.8 [9.4-16.6]; L. paracasei 25.4 [22.1-29] to 12.5 [9.2-16.4]; placebo 26.9 [23.4-30.6] to 11.8 [9.6-14.3]; P = 0.7). Results were similar when analysis was controlled for allergen-sensitization, or when only sensitized infants were analysed. No differences were found for secondary outcomes. No difference was observed in SCORAD-score between randomized and observational groups. CONCLUSION AND CLINICAL RELEVANCE: We found no benefit from supplementation with B. lactis or L. paracasei in the treatment of eczema, when given as an adjunct to basic topical treatment, and no effect on the progression of allergic disease from age 1 to 3 years.

Summary The dlt operon of Gram-positive bacteria encodes proteins required for the incorporation of d-alanine esters into cell wall-associated teichoic acids (TA). d-Alanylation of TA has been shown to be important for acid tolerance, resistance to antimicrobial peptides, adhesion, biofilm formation, and virulence of a variety of pathogenic organisms. The aim of this study was to determine the importance of d-alanylation for colonization of the gastrointestinal tract by Lactobacillus reuteri 100-23. Insertional inactivation of the dltA gene resulted in complete depletion of d-alanine substitution of lipoteichoic acids. The dlt mutant had similar growth characteristics as the wild type under standard in vitro conditions, but formed lower population sizes in the gastrointestinal tract of ex-Lactobacillus-free mice, and was almost eliminated from the habitat in competition experiments with the parental strain. In contrast to the wild type, the dlt mutant was unable to form a biofilm on the forestomach epithelium during gut colonization. Transmission electron microscope observations showed evidence of cell wall damage of mutant bacteria present in the forestomach. The dlt mutant had impaired growth under acidic culture conditions and increased susceptibility to the cationic peptide nisin relative to the wild type. Ex vivo adherence of the dlt mutant to the forestomach epithelium was not impaired. This study showed that d-alanylation is an important cell function of L. reuteri that seems to protect this commensal organism against the hostile conditions prevailing in the murine forestomach.

Purpose Chronic pouchitis is an important long-term complication following ileal pouch formation. Antibiotics reduce symptoms indicating bacteria play a role in pathogenesis. We analyzed and compared the bacterial content (microbiota) of stool collected from chronic pouchitis and familial adenomatous polyposis patients. Additionally, we compared the microbiota of chronic pouchitis patients on and off antibiotics. We aimed to determine which of the bacterial inhabitants of pouches had a role in the pathogenesis of pouchitis. Methods The stool microbiota of 17 patients with chronic pouchitis and of 15 familial adenomatous polyposis patients were analyzed by nucleic acid-based methods (temporal temperature gradient gel electrophoretic profiles, fluorescence in situ hybridization with flow cytometry). Results The composition of the stool of chronic pouchitis and familial adenomatous polyposis patients was markedly different. Electrophoretic profiles of the stool microbiota of familial adenomatous patients clustered at the 80% level of similarity, whereas those of chronic pouchitis patients were disparate. The results of fluorescence in situ hybridization analysis showed that bacteria not commonly present in human faeces, nor in the stool of familial adenomatous polyposis patients, comprised about 50% of the stool microbiota of untreated chronic pouchitis patients. Antibiotic treatment reduced the proportion of these unknown bacteria in the stool of every chronic pouchitis patient. Conclusion Chronic pouchitis is associated with a microbiota that contains bacteria not commonly associated with human faeces. These bacteria are reduced with antibiotics and are likely to be the pathogenic agents of chronic pouchitis.

Growth comparisons were made, using Shigella, Escherichia, and Salmonella cultures, in liquid and agar-solidified defined media containing beta-2-thienylalanine (beta-2-t). The comparisons were performed to determine the nature of growth inhibition by beta-2-t under different physical growth conditions. In a plate assay, with increasing beta-2-t mixed into the agar, inhibition of Escherichia and Shigella increased. However, Salmonella cultures were not inhibited even at the highest beta-2-t concentrations used. With beta-2-t added to liquid cultures, however, dose-response growth relationships were exhibited by all three genera. The differences occurring in beta-2-t inhibition between liquid and plate assay conditions were not due to composition of culture plates, time of challenge of cultures with beta-2-t, availability of oxygen and associated differences in ratios of volume of media to available surface area, selection of mutants in the plate assay, or to extractable substances from the agar. However, when beta-2-t diffusion into the liquid medium was delayed by using agar plug diffusion cultures, a physiological mechanism was demonstrable which largely protected Salmonella cultures, but not Escherichia and Shigella cultures, from growth inhibition.

Fourteen isolates of spiral-shaped bacteria were isolated from the caecum of conventional mice. All of the isolates had the same characteristics and resembled, but did not conform exactly to, the species Campylobacter faecalis.