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Purpose: Impaired gut barrier function is associated with systemic inflammation and many chronic diseases. Undigested dietary proteins are fermented in the colon by the gut microbiota which produces nitrogenous metabolites shown to reduce barrier function in vitro. With growing evidence of sex-based differences in gut microbiotas, we determined whether there were sex by dietary protein interactions which could differentially impact barrier function via microbiota modification., Methods: Fermentation systems were inoculated with faeces from healthy males (n = 5) and females (n = 5) and supplemented with 0.9 g of non-hydrolysed proteins sourced from whey, fish, milk, soya, egg, pea, or mycoprotein. Microbial populations were quantified using fluorescence in situ hybridisation with flow cytometry. Metabolite concentrations were analysed using gas chromatography, solid phase microextraction coupled with gas chromatography-mass spectrometry and ELISA., Results: Increased protein availability resulted in increased proteolytic Bacteroides spp (p < 0.01) and Clostridium coccoides (p < 0.01), along with increased phenol (p < 0.01), p-cresol (p < 0.01), indole (p = 0.018) and ammonia (p < 0.01), varying by protein type. Counts of Clostridium cluster IX (p = 0.03) and concentration of p-cresol (p = 0.025) increased in males, while females produced more ammonia (p = 0.02), irrespective of protein type. Further, we observed significant sex-protein interactions affecting bacterial populations and metabolites (p < 0.005)., Conclusions: Our findings suggest that protein fermentation by the gut microbiota in vitro is influenced by both protein source and the donor's sex. Should these results be confirmed through human studies, they could have major implications for developing dietary recommendations tailored by sex to prevent chronic illnesses., (© 2024. The Author(s).)

Objective: To investigate whether diets differing in fat content alter the gut microbiota and faecal metabolomic profiles, and to determine their relationship with cardiometabolic risk factors in healthy adults whose diet is in a transition from a traditional low-fat diet to a diet high in fat and reduced in carbohydrate., Methods: In a 6-month randomised controlled-feeding trial, 217 healthy young adults (aged 18-35 years; body mass index <28 kg/m 2 ; 52% women) who completed the whole trial were included. All the foods were provided during the intervention period. The three isocaloric diets were: a lower-fat diet (fat 20% energy), a moderate-fat diet (fat 30% energy) and a higher-fat diet (fat 40% energy). The effects of the dietary interventions on the gut microbiota, faecal metabolomics and plasma inflammatory factors were investigated., Results: The lower-fat diet was associated with increased α-diversity assessed by the Shannon index (p=0.03), increased abundance of Blautia (p=0.007) and Faecalibacterium (p=0.04), whereas the higher-fat diet was associated with increased Alistipes (p=0.04), Bacteroides (p<0.001) and decreased Faecalibacterium (p=0.04). The concentration of total short-chain fatty acids was significantly decreased in the higher-fat diet group in comparison with the other groups (p<0.001). The cometabolites p-cresol and indole, known to be associated with host metabolic disorders, were decreased in the lower-fat diet group. In addition, the higher-fat diet was associated with faecal enrichment in arachidonic acid and the lipopolysaccharide biosynthesis pathway as well as elevated plasma proinflammatory factors after the intervention., Conclusion: Higher-fat consumption by healthy young adults whose diet is in a state of nutrition transition appeared to be associated with unfavourable changes in gut microbiota, faecal metabolomic profiles and plasma proinflammatory factors, which might confer adverse consequences for long-term health outcomes., Trial Registration Number: NCT02355795; Results., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background/objectives: Individuals with high pre-treatment bacterial Prevotella-to-Bacteroides (P/B) ratio have been reported to lose more body weight on diets high in fiber than subjects with a low P/B ratio. Therefore, the aim of the present study was to examine potential differences in dietary weight loss responses between participants with low and high P/B., Subjects/methods: Eighty overweight participants were randomized (52 completed) to a 500 kcal/d energy deficit diet with a macronutrient composition of 30 energy percentage (E%) fat, 52 E% carbohydrate and 18 E% protein either high (≈1500 mg calcium/day) or low ( ≤ 600 mg calcium/day) in dairy products for 24 weeks. Body weight, body fat, and dietary intake (by 7-day dietary records) were determined. Individuals were dichotomized according to their pre-treatment P/B ratio derived from 16S rRNA gene sequencing of collected fecal samples to test the potential modification of dietary effects using linear mixed models., Results: Independent of the randomized diets, individuals with high P/B lost 3.8 kg (95%CI, 1.8,5.8; P < 0.001) more body weight and 3.8 kg (95% CI, 1.1, 6.5; P = 0.005) more body fat compared to individuals with low P/B. After adjustment for multiple covariates, individuals with high P/B ratio lost 8.3 kg (95% CI, 5.8;10.9, P < 0.001) more body weight when consuming above compared to below 30 g fiber/10MJ whereas this weight loss was 3.2 kg (95% CI, 0.8;5.5, P = 0.008) among individuals with low P/B ratio [Mean difference: 5.1 kg (95% CI, 1.7;8.6, P = 0.003)]. Partial correlation coefficients between fiber intake and weight change was 0.90 (P < 0.001) among individuals with high P/B ratio and 0.25 (P = 0.29) among individuals with low P/B ratio., Conclusions: Individuals with high P/B lost more body weight and body fat compared to individuals with low P/B, confirming that individuals with a high P/B are more susceptible to weight loss on a diet rich in fiber.

Background: Metritis is an inflammatory disease of the uterus caused by bacterial infection, particularly Bacteroides, Porphyromonas, and Fusobacterium. Bacteria from the environment, feces, or vagina are believed to be the only sources of uterine contamination. Blood seeps into the uterus after calving; therefore, we hypothesized that blood could also be a seeding source of uterine bacteria. Herein, we compared bacterial communities from blood, feces, and uterine samples from the same cows at 0 and 2 days postpartum using deep sequencing and qPCR. The vaginal microbiome 7 days before calving was also compared., Results: There was a unique structure of bacterial communities by sample type. Principal coordinate analysis revealed two distinct clusters for blood and feces, whereas vaginal and uterine bacterial communities were more scattered, indicating greater variability. Cluster analysis indicated that uterine bacterial communities were more similar to fecal bacterial communities than vaginal and blood bacterial communities. Nonetheless, there were core genera shared by all blood, feces, vaginal, and uterine samples. Major uterine pathogens such as Bacteroides, Porphyromonas, and Fusobacterium were part of the core genera in blood, feces, and vagina. Other uterine pathogens such as Prevotella and Helcococcus were not part of the core genera in vaginal samples. In addition, uterine pathogens showed a strong and significant interaction with each other in the network of blood microbiota, but not in feces or vagina. These microbial interactions in blood may be an important component of disease etiology. The copy number of total bacteria in blood and uterus was correlated; the same did not occur in other sites. Bacteroides heparinolyticus was more abundant in the uterus on day 0, and both B. heparinolyticus and Fusobacterium necrophorum were more abundant in the uterus than in the blood and feces on day 2. This indicates that B. heparinolyticus has a tropism for the uterus, whereas both pathogens thrive in the uterine environment early postpartum., Conclusions: Blood harbored a unique microbiome that contained the main uterine pathogens such as Bacteroides, Porphyromonas, and Fusobacterium. The presence of these pathogens in blood shortly after calving shows the feasibility of hematogenous spread of uterine pathogens in cows.

Quantitative PCR (qPCR) assays targeting the host-specific Bacteroides-Prevotella 16S rRNA genetic markers have been proposed as one of the promising approaches to identify the source of fecal contamination in environmental waters. One of the concerns of qPCR assays to environmental samples is the reliability of quantified values, since DNA extraction followed by qPCR assays are usually performed without appropriate sample process control (SPC) and internal amplification controls (IACs). To check the errors in sample processing and improve the reliability of qPCR results, it is essential to evaluate the DNA recovery efficiency and PCR amplification efficiency of the target genetic markers and correct the measurement results. In this study, we constructed a genetically-engineered Escherichia coli K12 strain (designated as strain MG1655 Δlac::kan) as sample process control and evaluated the applicability to environmental water samples. The recovery efficiency of the SPC strain MG1655 Δlac::kan was similar to that of Bacteroides fragilis JCM 11019, when DNA were extracted from water samples spiked with the two bacteria. Furthermore, the SPC was included in the qPCR assays with propidium monoazide (PMA) treatment, which can exclude the genetic markers from dead cells. No significant DNA loss was observed in the PMA treatment. The inclusion of both the SPC (strain MG1655 Δlac::kan) and IAC in qPCR assays with PMA treatment gave the assurance of reliable results of host-specific Bacteroides-Prevotella 16S rRNA genetic markers in environmental water samples.

Strains of gram-negative anaerobic rods were isolated from chinchilla (Chinchilla lanigera) faeces, and three strains, ST161(T), ST33 and ST37(T), were investigated taxonomically. Based on phylogenetic analyses and specific phenotypic characteristics, the three strains were allocated to the genus Bacteroides. Phylogenetic analyses of their 16S rRNA gene sequences revealed that strain ST161(T) formed a distinct line of descent, with highest sequence similarity to strain ST33 (98.7 %) and Bacteroides oleiciplenus JCM 16102(T) (97.7 %). High levels of DNA-DNA relatedness (79-89 %) were found between strains ST161(T) and ST33, but low levels were found between strain ST161(T) and B. oleiciplenus JCM 16102(T) (33-37 %) and between strain ST33 and B. oleiciplenus JCM 16102(T) (33-37 %). These data clearly indicated that strains ST161(T) and ST33 represent a single novel species. 16S rRNA gene sequence analyses showed that strain ST37(T) also formed a distinct line of descent, with highest sequence similarity to Bacteroides acidifaciens JCM 10556(T) (96.5 %) and Bacteroides caccae JCM 9498(T) (95.6 %). Analysis of hsp60 gene sequences also supported these relationships. Based on phenotypic and phylogenetic characteristics, two novel species, Bacteroides stercorirosoris sp. nov. and Bacteroides faecichinchillae sp. nov., are thus proposed. The type strains of B. stercorirosoris and B. faecichinchillae are ST161(T) ( = JCM 17103(T) = CCUG 60872(T)) and ST37(T) ( = JCM 17102(T) = CCUG 60873(T)), respectively. The DNA G+C contents of strains ST161(T) and ST37(T) were 45.7 and 41.0 mol%, respectively.

The interrelationships between our diets and the structure and operations of our gut microbial communities are poorly understood. A model community of 10 sequenced human gut bacteria was introduced into gnotobiotic mice, and changes in species abundance and microbial gene expression were measured in response to randomized perturbations of four defined ingredients in the host diet. From the responses, we developed a statistical model that predicted over 60% of the variation in species abundance evoked by diet perturbations, and we were able to identify which factors in the diet best explained changes seen for each community member. The approach is generally applicable, as shown by a follow-up study involving diets containing various mixtures of pureed human baby foods.

Gram-negative anaerobic rods were isolated from chinchilla (Chinchilla lanigera) faeces and three strains, ST170(T), ST180 and ST28(T), were investigated taxonomically. On the basis of phylogenetic analyses and specific phenotypic characteristics, the three strains belonged to the genus Bacteroides. Phylogenetic analysis of their 16S rRNA gene sequences revealed that strains ST170(T) and ST180 formed a single cluster and a distinct line of descent. Strain ST170(T) exhibited 99.7 % 16S rRNA gene sequence similarity with strain ST180 and 95.1, 94.6 and 94.4 % 16S rRNA gene sequence similarity with Bacteroides massiliensis JCM 13223(T), Bacteroides dorei JCM 13471(T) and Bacteroides vulgatus JCM 5826(T), respectively. Strain ST28(T) also formed a distinct line of descent and exhibited the highest 16S rRNA gene sequence similarity with Bacteroides uniformis JCM 5828(T) (98.1 %). Low DNA-DNA relatedness (1 %) between strain ST28(T) and B. uniformis JCM 5828(T) clearly indicated that they belonged to different species. Analysis of hsp60 sequences also supported these relationships. The DNA G+C contents of strains ST170(T) and ST28(T) were 45.2 and 41.0 mol%, respectively. On the basis of phenotypic characteristics and phylogenetic data, two novel species, Bacteroides chinchillae sp. nov. (type strain ST170(T)  = JCM 16497(T)  = CCUG 59335(T)) and Bacteroides rodentium sp. nov. (type strain ST28(T)  = JCM 16496(T)  = CCUG 59334(T)), are proposed.

Bacteroidales are attractive as water quality indicators because of their potential to discern sources of fecal pollution, and it is presumed that these bacteria do not multiply outside their host organisms. The persistence of a fecal Bacteroidales marker was monitored over 14 days in river water microcosms that varied in temperature from 10°C to 30°C and salinity from 0‰ to 30‰ by quantitative PCR (qPCR). Decay rates were estimated and compared to the results of other studies examining the survival and persistence of Bacteroidales markers by converting decay rates from other studies to a common decay rate unit. The log-linear decay rates estimated in this work ranged from -0.18 to -1.31 ln(C(T)/C(0)) day(-1), where C(T) is the threshold cycle and C(0) is the concentration of cells at time zero, which is comparable to findings in previous studies. Salinity had a positive effect on Bacteroidales marker persistence, while decay was more rapid at higher temperatures. Comparison of 16S rRNA gene clone libraries generated from microcosm samples indicated that most of the operational taxonomic unit (OTU) and phylogenetic diversity was found within samples and not between samples, indicating at least qualitatively that diverse lineages persist and likely have similar survival characteristics under most of the conditions examined. It was noted that the samples at higher salinities also had the smallest amount of diversity between samples as well as the lowest decay rates. This research also highlights the need for a repository of raw survival and persistence data if more sophisticated models of decay are to be employed and compared between different studies.

Temporal dynamics of the human gut microbiota is of fundamental importance for the development of proper gut function and maturation of the immune system. Here we present a description of infant gut ecological dynamics using a combination of nonlinear data modeling and simulations of the early infant gut colonization processes. Principal component analysis of infant microbiota 16S rRNA gene microarray data showed that the main directions of variation were defined by three phylum-specific probes targeting Bacteroides, Proteobacteria and Firmicutes. Nonlinear regression analysis identified several dynamic interactions between these three phyla. Simulations of the early phylum-level colonization process showed the relatively rapid establishment of an equilibrium community after an unstable initial phase. In general, varying the initial composition of phyla in the simulations had little bearing on the final equilibrium. The dynamic interaction model was found to maintain its predictive ability for Proteobacteria and Firmicutes well into the simulation, whereas Bacteroides densities tended to be underestimated, possibly due to host top-down selection for Bacteroides. In accordance with our model, initial perturbation of the microbiota by different mode of delivery (vaginal and C-section) did not affect the later phylum composition in the infants investigated. Considering the predictive ability and convergence of our phylum-level model, we now propose that deterministic bacterial-bacterial interactions are more important for shaping the human infant gut microbiota than previously anticipated.

Human fecal contamination of coral reefs is a major cause of concern. Conventional methods used to monitor microbial water quality cannot be used to discriminate between different fecal pollution sources. Fecal coliforms, enterococci, and human-specific Bacteroides (HF183, HF134), general Bacteroides-Prevotella (GB32), and Clostridium coccoides group (CP) 16S rDNA PCR assays were used to test for the presence of non-point source fecal contamination across the southwestern Puerto Rico shelf. Inshore waters were highly turbid, consistently receiving fecal pollution from variable sources, and showing the highest frequency of positive molecular marker signals. Signals were also detected at offshore waters in compliance with existing microbiological quality regulations. Phylogenetic analysis showed that most isolates were of human fecal origin. The geographic extent of non-point source fecal pollution was large and impacted extensive coral reef systems. This could have deleterious long-term impacts on public health, local fisheries and in tourism potential if not adequately addressed.

Background/aims: This study aimed to investigate the quantitative and qualitative changes of bacteria, Bacteroides, Bifidobacterium and Clostridium cluster IV in faecal microbiota associated with a vegetarian diet., Methods: Bacterial abundances were measured in faecal samples of 15 vegetarians and 14 omnivores using quantitative PCR. Diversity was assessed with PCR-DGGE fingerprinting, principal component analysis (PCA) and Shannon diversity index., Results: Vegetarians had a 12% higher abundance of bacterial DNA than omnivores, a tendency for less Clostridium cluster IV (31.86 +/- 17.00%; 36.64 +/- 14.22%) and higher abundance of Bacteroides (23.93 +/- 10.35%; 21.26 +/- 8.05%), which were not significant due to high interindividual variations. PCA suggested a grouping of bacteria and members of Clostridium cluster IV. Two bands appeared significantly more frequently in omnivores than in vegetarians (p < 0.005 and p < 0.022). One was identified as Faecalibacterium sp. and the other was 97.9% similar to the uncultured gut bacteriumDQ793301., Conclusions: A vegetarian diet affects the intestinal microbiota, especially by decreasing the amount and changing the diversity of Clostridium cluster IV. It remains to be determined how these shifts might affect the host metabolism and disease risks., (Copyright 2009 S. Karger AG, Basel.)

Three Gram-negative, anaerobic, rod-shaped bacteria (strains CB40, CB41 and CB42(T)) were isolated from human faeces. Based on phylogenetic analysis and specific phenotypic characteristics, these strains were included in the genus Bacteroides, and 16S rRNA gene sequence analysis indicated that these strains represented a novel species. The strains were most closely related to the type strains of Bacteroides barnesiae and Bacteroides salanitronis, with sequence similarities of 93.4 and 89.8 %, respectively. The G+C content of strain CB42(T) is 44.7 mol%. Major fatty acids were anteiso-C(15 : 0), C(16 : 0), iso-C(17 : 0) 3-OH and C(18 : 1)omega9c. On the basis of the data presented, a novel Bacteroides species, Bacteroides coprophilus sp. nov., is proposed, with CB42(T) (=JCM 13818(T)=DSM 18228(T)) as the type strain.

Two Gram-negative, anaerobic, non-spore-forming rod-shaped organisms were isolated from human faeces. These isolates were tentatively identified as Bacteroides based on morphological and biochemical criteria and appeared closely related to Bacteroides vulgatus ATCC 8482(T). The 16S rRNA gene sequence analysis showed that the isolates were highly related to each other (99.5 %) and confirmed their placement in the genus Bacteroides. 16S rRNA gene sequence similarity values with close phylogenetic neighbours Bacteroides vulgatus ATCC 8482(T) (96 %) and Bacteroides massiliensis CCUG 48901(T) (93 %) preliminarily demonstrated that the organisms represented a novel species. The results of phenotypic, chemotaxonomic and 16S rRNA gene sequence analyses, and DNA-DNA homology values provided evidence that these two unknown isolates represent a single species and should be assigned to a novel species of the genus Bacteroides, as Bacteroides dorei sp. nov. The type strain is JCM 13471(T) (=DSM 17855(T)).

Two strains, 199T and 176, of Gram-negative, anaerobic, rod-shaped, non-spore-forming bacteria were isolated during studies of microbiota in human faeces using polyamine-deficient medium. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the isolated strains belonged to the genus Bacteroides. The G+C content (42.4-43.0 mol%) and major fatty acid composition (anteiso-C15:0, 31.8-36.2 %) supported the affiliation of the two strains to the genus Bacteroides. 16S rRNA gene sequence similarities with their closest neighbours, Bacteroides thetaiotaomicron and Bacteroides ovatus, ranged from 94.6 to 96.5 %. DNA-DNA hybridization and phenotypic analysis showed that the two strains belonged to the same species (DNA-DNA relatedness of 89 %) and were distinct from their close relatives, B. thetaiotaomicron and B. ovatus (<23 % DNA-DNA relatedness). On the basis of these data, a novel species of the genus Bacteroides, Bacteroides finegoldii sp. nov., is proposed, comprising the designated type strain 199T (=JCM 13345T=DSM 17565T) and strain 176 (=JCM 13346).

During studies of the microbiota of human faeces, five strains of Gram-negative anaerobic rods were isolated following growth in a polyamine-deficient medium. These strains belonged to the genus Bacteroides on the basis of 16S rRNA gene sequence data. 16S rRNA gene sequence similarity between one of the strains, 341T, and recognized species within the genus Bacteroides was <95 %. The DNA G+C content (44 mol%) and major fatty acid composition (anteiso-C(15 : 0), 32.0 %) supported the affiliation of strain 341(T) to the genus Bacteroides. Biochemical tests and DNA-DNA hybridization analysis demonstrated that strain 341T was distinct from Bacteroides uniformis and Bacteroides helcogenes, to which it was related most closely. On the basis of these data, a novel Bacteroides species, Bacteroides intestinalis sp. nov., is proposed with strain 341T (= JCM 13265T = DSM 17393T) as the type strain.

To verify the influence of some predominant components from indigenous microbiota on systemic immunological responses during experimental Chagas disease, germ-free NIH Swiss mice were mono-associated with Escherichia coli, Enterococcus faecalis, Bacteroides vulgatus or Peptostreptococcus sp. and then infected with the Y strain of Trypanosoma cruzi. All the mono-associations predominantly induced a Th1 type of specific immune response to the infection by T. cruzi. A direct correlation was observed between a higher survival rate and increased IFN-gamma and TNF-alpha production (P<0.05) in E. faecalis-, B. vulgatus-, and Peptostreptococcus-associated mice. Moreover, higher levels of anti-T. cruzi IgG1 and anti-T. cruzi IgG2a were also found in mono-associated animals after infection. On the other hand, with the exception of E. faecalis-associated mice, mono-association induced a lower IL-10 production after infection (P<0.05) when compared with germ-free animals. Interestingly, spleen cell cultures from non-infected germ-free and mono-associated mice spontaneously produced higher levels (P<0.05) of IL-10 than cultures from infected mono-associated mice, except again for E. faecalis-associated animals. In conclusion, the presence of the components of the indigenous microbiota skews the immune response towards production of inflammatory cytokines during experimental infection with T. cruzi in gnotobiotic mice. However, the degree of increase in production of cytokines depends on each bacterial component.

Nine strains of Gram-negative, anaerobic rod were isolated from human faeces. Based on phylogenetic analysis and specific phenotypic characteristics, these strains were included within the Bacteroides cluster and were divided into two clusters. Strains from the two clusters showed 16S rRNA gene sequence similarities of 90.4 and 92.7% to the nearest recognized species, Bacteroides vulgatus. The strains also formed two clusters exhibiting a 16S rRNA gene sequence divergence of approximately 6%. DNA-DNA hybridization studies confirmed that the two novel strain clusters were distinct from each other. Based on the phenotypic and phylogenetic findings, two novel species, Bacteroides plebeius sp. nov. and Bacteroides coprocola sp. nov., are proposed, each representing one of the two strain clusters. The DNA G+C content of the type strains were 43.9 mol% for B. plebeius (M12(T)=JCM 12973(T)=DSM 17135(T)) and 42.4 mol% for B. coprocola (M16(T)=JCM 12979(T)=DSM 17136(T)).

One-day old chickens were treated with a faecal suspension and faecal samples were cultivated either in non-selective broth (Viande Levure broth) or in broths selective for Lactobacillus spp., Bacteroides spp., faecal enterococci and coliforms. The chickens were infected 48 h later with 10(4) colony-forming units of nalidixic-acid resistant Salmonella kedougou and examined seven days later. Faecal suspensions and faecal samples cultivated in non-selective broth exerted a protection against Salmonella infection; no protection was obtained with faecal samples cultivated in selective broths, administered either alone or in combination.

Manasan is an adapted formula for infants on the basis of cow's milk simulating the mode of action of human milk on faeces-pH and faeces microflora. In two temporally separated tests the effect of Manasan-feeding on faeces-pH, faeces flora, and acid-base-homeostasis was controlled and compared with the effect of human milk and Ki-Na-formula. With Manasan fed up from birth or following breast-feeding faeces-pH was to be found in an acid range, clearly. With Ki-Na the faeces-pH was situated in the neutral range. With Manasan the bacteria flora revealed a noteworthy decrease in the number of Bacteroides germs achieving a non-putrefactive milieu. Concerning the acid-base-homeostasis as with human milk so with Manasan late metabolic acidosis were to meet rarely. The experiments revealed that in important parameters, particularly with microecological signs, Manasan is comparable with human milk.

Bacteroides spp. were isolated from the faeces of neonates and identified by rapid modifications of established conventional methods. Gram-negative anaerobic bacilli were recovered from 12 out of 16 neonates and a heavy growth of Bacteroides spp. was obtained from all 12 specimens. Twelve representative isolates from each subject were selected for identification; 141 of the 144 Bacteroides isolates belonged to the B. fragilis group and three to the B. melaninogenicus/oralis group. Eight species were represented within the B. fragilis group. B. vulgatus (c. 46%) and B. thetaiotaomicron (c. 30%) were the predominant species. B. fragilis, the type-species of the group, formed only a small proportion of neonatal faecal flora. The proportional representation of individual species were similar to that found in adults but B. asaccharolyticus was not represented.