Features of intestinal flora in children with food protein-induced proctocolitis based on high-throughput sequencing / 中国当代儿科杂志

OBJECTIVES@#To study the features of intestinal flora in children with food protein-induced proctocolitis (FPIP) by high-throughput sequencing.@*METHODS@#A total of 31 children, aged <6 months, who experienced FPIP after exclusive breastfeeding and attended the outpatient service of the Third Affiliated Hospital of Zunyi Medical University from October 2018 to February 2021 were enrolled as the FPIP group. Thirty-one healthy infants were enrolled as the control group. Fecal samples were collected to extract DNA for PCR amplification. High-throughput sequencing was used to perform a bioinformatics analysis of 16S rDNA V3-V4 fragments in fecal samples.@*RESULTS@#The diversity analysis of intestinal flora showed that compared with the control group, the FPIP group had a lower Shannon index for diversity (P>0.05) and a significantly higher Chao index for abundance (P<0.01). At the phylum level, the intestinal flora in both groups were composed of Firmicutes, Actinobacteria, Proteobacteria, and Bacteroidetes. Compared with the control group, the FPIP group had a significant reduction in the composition ratio of Actinobacteria (P<0.001) and a significant increase in the composition ratio of Proteobacteria (P<0.05). At the genus level, the intestinal flora in the FPIP group were mainly composed of Escherichia, Clostridium, Enterococcus, Klebsiella, and Bifidobacterium, and the intestinal flora in the control group were mainly composed of Bifidobacterium and Streptococcus. Compared with the control group, the FPIP group had a significant reduction in the composition ratio of Bifidobacterium and Ruminococcus (P<0.05) and significant increases in the composition ratios of Clostridium and Shigella (P<0.05).@*CONCLUSIONS@#Compared with the control group, the FPIP group has a reduction in the diversity of intestinal flora and an increase in their abundance, and there are certain differences in several bacterial genera. These results suggest that changes in the composition of intestinal flora at genus level may play an important role in the development and progression of FPIP.

Anaerobic bacteria in the intestinal microbiota of Brazilian children

OBJECTIVE: Changes in the neonatal gut environment allow for the colonization of the mucin layer and lumen by anaerobic bacteria. The aim of the present study was to evaluate Bifidobacterium, Lactobacillus and Lactococcus colonization through the first year of life in a group of 12 Brazilian infants and to correlate these data with the levels of Escherichia coli. The presence of anaerobic members of the adult intestinal microbiota, including Eubacterium limosum and Faecalibacterium prausnitzii, was also evaluated. METHODS: Fecal samples were collected during the first year of life, and 16S rRNA from anaerobic and facultative bacteria was detected by real-time PCR. RESULTS: Bifidobacterium was present at the highest levels at all of the studied time points, followed by E. coli and Lactobacillus. E. limosum was rarely detected, and F. prausnitzii was detected only in the samples from the latest time points. CONCLUSION: These results are consistent with reports throughout the world on the community structure of the intestinal microbiota in infants fed a milk diet. Our findings also provide evidence for the influence of the environment on intestinal colonization due to the high abundance of E. coli. The presence of important anaerobic genera was observed in Brazilian infants living at a low socioeconomic level, a result that has already been well established for infants living in developed countries.

Effects of Probiotics on Gut Microbiota in Patients with Inflammatory Bowel Disease: A Double-blind, Placebo-controlled Clinical Trial / 대한소화기학회지

BACKGROUND/AIMS: Several clinical trials have revealed various advantages for probiotics in inflammatory bowel disease (IBD). The aim of this study was to further investigate the effects of probiotic yogurt consumption on gut microbiota in patients with this disease. METHODS: A total of 305 participants were divided into three groups; group A (IBD patients receiving probiotic yogurt; n=105), group B (IBD patients receiving placebo; n=105), and control group (healthy individuals receiving probiotic yogurt; n=95). Stool samples were collected both before and after 8 weeks of intervention; and population of Lactobacillus, Bifidobacterium and Bacteroides in the stool specimens was measured by Taqman real-time PCR method. ': By the end of the intervention, no significant variations in the mean weight and body mass index were observed between three groups (p>0.05). However, the mean numbers of Lactobacillus, Bifidobacterium, and Bacteroides in group A were significantly increased compared to group B (p<0.001, p<0.001, and p<0.01, respectively). There were also significant differences in the mean numbers of either of three bacteria between group A and the healthy control group; however, these differences between two groups were observed both at baseline and the end of the intervention. CONCLUSIONS: Consumption of probiotic yogurt by patients with IBD may help to improve intestinal function by increasing the number of probiotic bacteria in the intestine and colon. However, many more studies are required in order to prove the concept.

Establishment of the bacterial fecal community during the first month of life in Brazilian newborns

OBJECTIVE: The establishment of the intestinal microbiota in newborns is a critical period with possible long-term consequences for human health. In this research, the development of the fecal microbiota of a group of exclusively breastfed neonates living in low socio-economic conditions in the city of São Paulo, Brazil, during the first month of life, was studied. METHODS: Fecal samples were collected from ten neonates on the second, seventh, and 30th days after birth. One of the neonates underwent antibiotic therapy. Molecular techniques were used for analysis; DNA was extracted from the samples, and 16S rRNA libraries were sequenced and phylogenetically analyzed after construction. A real-time polymerase chain reaction (PCR) was performed on the samples taken from the 30th day to amplify DNA from Bifidobacterium sp. RESULTS: The primary phylogenetic groups identified in the samples were Escherichia and Clostridium. Staphylococcus was identified at a low rate. Bifidobacterium sp. was detected in all of the samples collected on the 30th day. In the child who received antibiotics, a reduction in anaerobes and Escherichia, which was associated with an overgrowth of Klebsiella, was observed throughout the experimental period. CONCLUSION: The observed pattern of Escherichia predominance and reduced Staphylococcus colonization is in contrast with the patterns observed in neonates living in developed countries.

Faecal bifidobacteria in Indian neonates & the effect of asymptomatic rotavirus infection during the first month of life.

Background & Objectives: Bifidobacteria colonize the gut after the first week of life and remain an important component of the gut microbiota in infancy. This study was carried out to characterize the diversity and number of bifidobacteria colonizing the gut in Indian neonates and to investigate whether asymptomatic infection with rotavirus in the first month of life affected gut colonization by bidifobacteria. Methods: DNA was isolated from faeces of 14 term-born neonates who were under surveillance for rotavirus infection. Bacterial and bifidobacterial diversity was evaluated by temporal temperature gradient electrophoresis (TTGE) of 16S rDNA amplified using total bacteria and bifidobacteria-specific primers. Real time PCR, targeting 16S rDNA, was used to quantitate faecal bifidobacteria and enterobacteria. Results: TTGE of conserved bacterial 16S rDNA showed 3 dominant bands of which Escherichia coli (family Enterobacteriaceae) and Bifidobacterium (family Bifidobacteriaceae) were constant. TTGE of Bifidobacterium genus-specific DNA showed a single band in all neonates identified by sequencing as Bifidobacterium longum subsp. infantis. Faecal bifidobacterial counts (log10 cfu/g faeces) ranged from 6.1 to 9.3 and enterobacterial counts from 6.3 to 9.5. Neonates without and with rotavirus infection in the first week of life did not show significant differences in the median count of bifidobacteria (log10 count 7.48 vs. 7.41) or enterobacteria (log10 count 8.79 vs. 7.92). Interpretation & Conclusions: B. longum subsp. infantis was the sole bifidobacterial species colonizing the gut of Indian neonates. Asymptomatic rotavirus infection in the first month of life was not associated with alteration in faecal bifidobacteria or enterobacteria.