Fecal microbiota analysis of children with small intestinal bacterial overgrowth among residents of an urban slum in Brazil

Abstract

Children who lived in a slum and were diagnosed with small intestinal bacterial overgrowth showed lower H/A Z-scores and hemoglobin levels. Furthermore, differences were observed in the fecal microbiota of children with small intestinal bacterial overgrowth, when compared to those without it; specifically, a higher frequency and count of Salmonella, and lower counts of Firmicutes and total Eubacteria.

Stunted childhood growth is associated with decompartmentalization of the gastrointestinal tract and overgrowth of oropharyngeal taxa

“…SIBO is prevalent in children living in difficult sanitary and economic situations, where they are often exposed to sewage and waste material. Studies of children living in shantytowns in South America and Asia have detected SIBO at a prevalence of 16-61% (23,(25)(26)(27)(28). SIBO has also been described in children affected by PEE (23) and in undernourished children living in Gambia (29), Indonesia (30), and Nigeria (31).…”

“…However, previous studies have been limited. Most of them used the hydrogen or lactulose breath test to diagnose the presence of SIBO (in this test, bacterial fermentation of an ingested sugar leads to increased hydrogen in the breath); however, this approach does not provide any information on the community composition of SIBO (25)(26)(27)(28). Furthermore, these studies included only a limited number of participants or were performed before next-generation sequencing methods became available.…”

Randomized, Double-Blind, Placebo-Controlled Parallel Clinical Trial Assessing the Effect of Fructooligosaccharides in Infants with Constipation

“…The standard curve for all of the analyses was created by amplifying a Topo TA plasmid (Invitrogen, ThermoFisher, Waltham, MA, USA) carrying a fragment of the reference gene previously amplified by conventional PCR, and its specificity was confirmed by sequencing and BLAST system alignment. With the molecular mass of the plasmid and insert known, it is possible to calculate the copy number as follows: mass in daltons (g/mol) = (size of double-stranded (ds) product in base pairs (bp)) (330 Da × 2 nucleotides (nt)/bp) [ 29 , 30 , 31 ]. If the copy number and the concentration of the plasmid DNA are known, the number of molecules added to subsequent real-time PCR runs can be calculated, thus providing a standard for determining the copy numbers of specific genes [ 29 , 30 , 31 ].…”

“…With the molecular mass of the plasmid and insert known, it is possible to calculate the copy number as follows: mass in daltons (g/mol) = (size of double-stranded (ds) product in base pairs (bp)) (330 Da × 2 nucleotides (nt)/bp) [ 29 , 30 , 31 ]. If the copy number and the concentration of the plasmid DNA are known, the number of molecules added to subsequent real-time PCR runs can be calculated, thus providing a standard for determining the copy numbers of specific genes [ 29 , 30 , 31 ]. The real-time PCR results are expressed as log CFU per gram of stool (log CFU/g) using the average number of copies of 16S rRNA genes in each bacterium to normalize the counts [ 29 , 30 , 31 ].…”

“…If the copy number and the concentration of the plasmid DNA are known, the number of molecules added to subsequent real-time PCR runs can be calculated, thus providing a standard for determining the copy numbers of specific genes [ 29 , 30 , 31 ]. The real-time PCR results are expressed as log CFU per gram of stool (log CFU/g) using the average number of copies of 16S rRNA genes in each bacterium to normalize the counts [ 29 , 30 , 31 ].…”